Download Neet PG Physiology MCQs Question Bank
syndrome Signsandsymptomsofdecompressionsickness Bubble Signs&symptoms(clinical DCStype location manifestations) Mostlylarge Localizeddeeppain,rangingfrom Musculoskeletal joints mildtoexcruciating.Sometimes (elbows, adullache,butrarelyasharppain, shoulders,hip, Activeandpassivemotionofwrists,knees, thejointaggravatesthepain,Theankles) painmaybereducedbybending thejointtofindamorecomfortableposition,Ifcausedbyaltitude,paincanoccurimmediatelyoruptomanyhourslater. Cutaneous Skin Etching,usuallyaroundtheears,face,neck,arms,anduppertorso,Sensationoftinyinsectscrawlingovertheskin(formication),Mottledormarbledskinusuallyaroundtheshoulders,upperchestandabdomen,withitching,Swellingoftheskin,accompaniedbytinyscar-likeskindepressions(pittingedema) Neurologic Brain Alteredsensation,tinglingornumbnessparesthesias,increasedsensitivityhyperesthesia,Confusionormemoryloss(amnesia),Visualabnormalities,Unexplainedmoodorbehaviourchanges,Seizures,unconsciousness Neurologic Spinalcord Ascendingweaknessorparalysisinthelegs,Girdlingabdominalorchestpain,Urinaryincontinenceandfaecalincontinence Constitutional Wholebody Headache,Unexplainedfatigue,Generalisedmalaise,poorlylocalisedaches
localisedaches Audiovestibular Lossofbalance,Dizziness,vertigo, Innerear nausea,vomiting,Hearingloss Pulmonary Lungs Drypersistentcough,Burningchestpainunderthesternum,aggravatedbybreathing,Shortnessofbreath
2.Preloadmeasures? a)Endsystolicvolume b)Enddiastolicvolume c)Peripheralresistance d)Strokevolume CorrectAnswer-BEnddiastolicvolumeREF:Guyton'sphysiology22ndeditionpage111,http://en.wikipedia.org/wiki/Preload_%28cardiology%29"Forcardiaccontraction,thepreloadisusuallyconsideredtobetheend-diastolicpressurewhentheventriclehasbecomefilled"Quantitatively,preloadcanbecalculatedas WhereLVEDP=Leftventricularenddiastolicpressure,LVEDR=Leftventricularenddiastolicradius(attheventricle'smidpoint),andh=thicknessoftheventricle.ThiscalculationisbasedontheLawofLaplace.
3.CentralChemoreceptorsaremostsensitive tofollowingchangesinblood: a)TPCO2 b)IPCO2 c)TH+ d)TPO2 CorrectAnswer-A TPCO2
4.WhichofthefollowingstatementisTRUEaboutBohr'seffect? a)DecreasedaffinityofHbto02isassociatedwithdecreasedpH &increasedC02 b)DecreasedaffinityofHbto02isassociatedwithincreasedpH &decreasedC02 c)DecreasedaffinityofHbto02isassociatedwithdecreasedpH &C02 d)DecreasedaffinityofHbto02isassociatedwithincreasedpH &C02 CorrectAnswer-AThedecreaseinO2affinityofhemoglobinwhenthepHofbloodfallsiscalledtheBohr effect. Itiscloselyrelatedtothefactthatdeoxygenatedhemoglobin(deoxyhemoglobin)bindsH+ moreactivelythandoesoxygenatedhemoglobin(oxyhemoglobin). ThepHofbloodfallsasitsCO2contentincreases,sothatwhenthePCO2rises,thecurve shiftstotherightandtheP50rises.Ref:BarrettK.E.,BarmanS.M.,BoitanoS.,BrooksH.L.(2012).Chapter35.GasTransport&pH.InK.E.Barrett,S.M.Barman,S.Boitano,H.L.Brooks(Eds),Ganong'sReviewofMedicalPhysiology,24e.
5.Glandsareclassifieddependingupontheirmodeofsecretion.Sebaceousgland isanexampleofwhichofthefollowingtypeofgland? a)Eccrine b)Apocrine c)Holocrine d)Paracrine CorrectAnswer-CSebaceousglandsareholocrineglands.Holocrineglandsarethoseinwhichthecellafterfillingwithsecretoryproductdiesandisexpelledalongwithitscontent. Eccrineglandsarethoseinwhichsecretoryproductisexpelledbyexocytosis.Egsweat glandsinvolvedinthermoregulationandreceivingcholinergicsympatheticinnervation. Apocrineglandsarethoseinwhichthesecretoryproductaccumulatesintheapical cytoplasmandisexpelledoutbypinchingoftheapicalplasmamembrane.Egmammary glandandapocrinetypeofsweatglandsthatareactiveafterpubertyandarefoundinthe skinofaxillaandaroundgenitalorgans.Ref:ClinicalAnatomy:(aProblemSolvingApproach)ByKulkarnipage9
6.Ruffiniendorganisassociatedwithsensationof: a)SustainedPressure b)Heat c)Touch d)Noneoftheabove CorrectAnswer-AMeissner'scorpusclesaredendritesencapsulatedinconnectivetissueandrespondtochangesintextureandslowvibrations.Merkelcellsareexpandeddendriticendings,andtheyrespondtosustainedpressureandtouch.Ruffinicorpusclesareenlargeddendriticendingswithelongatedcapsules,andtheyrespondtosustainedpressure.Paciniancorpusclesconsistofunmyelinateddendriticendingsofasensorynervefiber,2mindiameter,encapsulatedbyconcentriclamellaeofconnectivetissuethatgivetheorgantheappearanceofacocktailonion.Thesesreceptorsrespondtodeeppressureandfastvibration.Ref:BarrettK.E.,BarmanS.M.,BoitanoS.,BrooksH.L.(2012).Chapter8.SomatosensoryNeurotransmission:Touch,Pain,andTemperature.InK.E.Barrett,S.M.Barman,S.Boitano,H.L.Brooks(Eds),Ganong'sReviewofMedicalPhysiology,24e.
7.Loweresophagealsphincterpressureisincreasedbyallofthefollowing substances,EXCEPT: a)Gastrin b)Vasopressin c)Glucagon d)Secretin CorrectAnswer-DTheloweresophagealsphincter,aphysiologicentitybutnotananatomicstructure,playsanimportantpartinpreventinggastroesophagealreflux.Neural,hormonal,myogenic,andmechanicalfactorsinfluencethetoneofthesphincter.Gastrin,vasopressin,glucagon,adrenergicagonists,andcholinergicagentsincreasethepressure.Secretinhastheoppositeeffect.
8.Colipaseis: a)IssecretedbyOxynticcells b)Issecretedintheactiveform c)Helpsgastriclipase d)EncodedbythegeneCLPS CorrectAnswer-DColipaseisasmallproteincofactorneededbypancreaticlipaseforefficientdietarylipidhydrolyisis.Itissecretedasaninactiveformprocolipasebythepancreasandintheintestinalitisconvertedtotheactiveformbytrypsin.Efficientabsorptionofdietaryfatsisdependentontheactionofpancreatictriglyceridelipase.ColipasebindstotheC-terminal,non-catalyticdomainoflipase,therebystabilisingasactiveconformationandconsiderablyincreasingtheoverallhydrophobicbindingsite.ItisencodedbythegeneCLPS. Ref:Ganong'sReviewofHumanPhysiology,21stEdition,Page476
9.Ironabsorptionisincreasedbythefollowingfactorindiet: a)Vitamin-C b)Phyticacid c)Fibrediet d)Phosphates CorrectAnswer-AInavegetariandiet,nonhemeironisabsorbedverypoorlybecauseoftheinhibitoryactionofavarietyofdietarycomponents,particularlyphosphates,phytatesandhighfibrecontent.Ascorbicacidandmeatfacilitatetheabsorptionofnonhemeiron.Ascorbateformscomplexeswithand/orreducesferrictoferrousiron.Meatfacilitatestheabsorptionofironbystimulatingproductionofgastricacid;othereffectsalsomaybeinvolved.Eitherofthesesubstancescanincreaseavailabilityseveralfold.Ref:KaushanskyK.,KippsT.J.(2011).Chapter37.HematopoieticAgents:GrowthFactors,Minerals,andVitamins.InB.C.Knollmann(Ed),Goodman&Gilman'sThePharmacologicalBasisofTherapeutics,12e.
10.Whichofthefollowingstatementregardingloweresophagealsphincteris TRUE? a)Ithasnotonicactivity b)Ithasatonewhichisprovidedbythesympatheticsystem c)Relaxesonincreasingabdominalpressure d)Relaxesaheadoftheperistalticwave CorrectAnswer-DDuringswallowingwhentheperistalticwavesweepdowntheesophagusthegastroesophagealsphincterrelaxessothatthebolusoffoodcanpassintothestomach.DistanceoftheLowerEsophagealSphincterfromtheupperincisorsis37.5cmtheloweresophagealsphincteristonicallyactivebutrelaxesonswallowing.ThistonicactivityoftheLESbetweenmealspreventsrefluxofgastriccontentsintotheesophagus.itstoneisunderneuralcontrolbytheparasympatheticnervoussystem.ContractionofLESiscausedbythereleaseofacetylcholinefromthevagusandreleaseofNOandVIPfrominterneuronsinnervatedbyothervagalfiberscausesittorelax.Ref:FundamentalsofHumanPhysiologyByLauraleeSherwoodpage447.Ganong'sReviewofMedicalPhysiology,24eCHAPTER27.
11.Trueaboutvolumereceptorsareall,EXCEPT: a)Theyarelowpressurereceptors b)Theyprovideafferentsforthirstcontrol c)Theyarelocatedincarotidsinus d)Theymediatevasopressinrelease CorrectAnswer-CThelow-pressurebaroreceptorsarelocatedinthevenaecavaeandthepulmonaryveins,andintheatria.Theyarealsocalledvolumereceptors.Thesereceptorsrespondtochangesinthewalltension,whichisproportionaltothefillingstateofthelowpressuresideofcirculation(below60mmHg).Theirimpulsesregulatethesecretionofantidiuretichormone(ADH/Vasopressin),reninandaldosterone. Thelow-pressurebaroreceptorshavebothcirculatoryandrenaleffects;theyproducechangesinhormonesecretion,resultinginprofoundeffectsontheretentionofsaltandwater;theyalsoinfluenceintakeofsaltandwater.
12.InanECGthecardiaceventcorrespondingtotheSTsegmentis: a)Atrialdepolarisation b)Ventriculardepolarisation c)Atrialrepolarisation d)Ventricularrepolarisation CorrectAnswer-DPR?IntervalcorrespondswithatrialdepolarisationandconductionthroughAVnodeQRS?correspondswithVentriculardepolarisation+atrialrepolarisationQT?correspondswithventriculardepolarisation+ventricularrepolarisationRef:ReviewofMedicalPhysiologybyGanong,20thEdition,Page532.
13.WhichoneofthefollowingistheCORRECTstatementregardingcoronary bloodflow? a)Coronarybloodflowisdirectlyrelatedtoperfusionpressureand inverselyrelatedtoresistance b)Coronarybloodflowisinverselyrelatedtoperfusionpressure anddirectlyrelatedtoresistance c)Coronarybloodflowisdirectlyrelatedtoperfusionpressureand alsotoresistance d)Coronarybloodflowisinverselyrelatedtobothpressureand resistance CorrectAnswer-ACoronarybloodflowisdirectlyrelatedtotheperfusionpressure(aorticdiastolicpressure)andthedurationofdiastole.Becausecoronaryflowdropstonegligiblevaluesduringsystole,thedurationofdiastolebecomesalimitingfactorformyocardialperfusionduringtachycardia.Coronarybloodflowisinverselyproportionaltocoronaryvascularresistance.Resistanceisdeterminedmainlybyintrinsicfactors--includingmetabolicproductsandautonomicactivity--andbyvariouspharmacologicagents.Damagetotheendotheliumofcoronaryvesselshasbeenshowntoaltertheirabilitytodilateandtoincreasecoronaryvascularresistance. Ref:KatzungB.G.(2012).Chapter12.Vasodilators&theTreatmentofAnginaPectoris.InB.G.Katzung,S.B.Masters,A.J.Trevor(Eds),Basic&ClinicalPharmacology,12e.
14.Depressorreflex,Bezold-Jarischreflex,producedbythefollowingstimulus: a)Atrialoverload b)Myocardialinfarction c)Ventriculardistension d)Isotonicexercise CorrectAnswer-CVentriculardistensioncanproduceapowerfuldepressorreflexcalledtheBezold-Jarischreflex;vagalafferentsofthiscardiopulmonaryreflexarealsoactivatedbychemicalstimulation(eg,prostanoids,cytokines,serotonin,andclassically,Veratrumalkaloids).Thecentralconnectionsforthisreflexareinthenucleustractussolitarii,whichhasbothsympatheticandparasympatheticsynapses.Ref:HoitB.D.,WalshR.A.(2011).Chapter5.NormalPhysiologyoftheCardiovascularSystem.InV.Fuster,R.A.Walsh,R.A.Harrington(Eds),Hurst'sTheHeart,13e.
15.Allofthefollowingcelltypesundergocelldivision,EXCEPT: a)Pericyte b)Cardiacmusclecell c)Smoothmusclecell d)Satellitecellofskeletalmuscle CorrectAnswer-BMyocytecelldivisioninthehumanheartceasesafewweeksafterbirth.Thereafter,enlargementoftheheartisasaresultofcellhypertrophyorthelayingdownofcollagenintheextracellularspace.DNAturnoverisalmostundetectableexceptinpathologicstates.Approximately20%ofmyocytesinthehumanhearthavetwonuclei,sothatcellseparation,ratherthanmitosis,couldbringaboutasmallincreaseinthetotalcellnumber.Ref:FrancisG.S.,TangW.,WalshR.A.(2011).Chapter26.PathophysiologyofHeartFailure.InV.Fuster,R.A.Walsh,R.A.Harrington(Eds),Hurst'sTheHeart,13e.
16.DirectFickmethodofmeasuringcardiacoutputrequiresestimationof: a)O2contentofarterialblood b)O2consumptionperunittime c)ArteriovenousO2difference d)Alloftheabove CorrectAnswer-DDirectFickmethodandtheindicatordilutionmethodareusedformeasuringcardiacoutput.TheFickprinciplestatesthattheamountofasubstancetakenupbyanorgan(orbythewholebody)perunitoftimeisequaltothearteriallevelofthesubstanceminusthevenouslevel(A-Vdifference)timesthebloodflow.Botharterialandmixedvenous(whichisequaltopulmonaryartery)bloodmustbesampledinthismethod.TheprinciplecanbeusedtodeterminecardiacoutputbymeasuringtheamountofO2consumedbythebodyinagivenperiodanddividingthisvaluebytheA-Vdifferenceacrossthelungs.Ref:BarrettK.E.,BarmanS.M.,BoitanoS.,BrooksH.L.(2012).Chapter30.TheHeartasaPump.InK.E.Barrett,S.M.Barman,S.Boitano,H.L.Brooks(Eds),Ganong'sReviewofMedicalPhysiology,24e.
17.Primitiveredcellsfirstoriginatesintheearlyembryoniclifeisin: a)Liver b)Yolksac c)Bonemarrow d)Spleen CorrectAnswer-BDuringembryogenesis,hematopoiesisoccursinextraembryonicyolksac,thefetalliver,thethymus,andthepretermmarrow.Theoriginofhematopoieticcellsiscloselytiedtogastrulation,theformationofmesodermcells,andtotheemergenceoftheendotheliallineage.Hematopoiesisisfirstestablishedsoonafterimplantationoftheblastocyst,withtheappearanceofprimitiveerythroidcellsinbloodislandsoftheyolksacbeginningatday18ofgestation. "Primitive"redcellsderivedfromtheyolksacconstituteadistincttransienterythroidlineagethatdiffersfrom"definitive"redcellsthatsubsequentlymatureinthefetalliverandmarrow.Ref:PalisJ.,SegelG.B.(2010).Chapter6.HematologyoftheFetusandNewborn.InJ.T.Prchal,K.Kaushansky,M.A.Lichtman,T.J.Kipps,U.Seligsohn(Eds),WilliamsHematology,8e.
18.Transpulmonarypressureisthedifferencebetween: a)Thebronchusandatmosphericpressure b)Pressureinalveoliandintrapleuralpressure c)Atmosphereandintrapleuralpressure d)Atmosphereandintraalveolarpressure CorrectAnswer-BTranspulmonarypressureisthepressuredifferencebetweenalveolarpressureandintrapleuralpressure.Beforethestartofinspirationorattheendofexpirationitisabout+5cmH2O.Positivetranspulmonarypressurekeepsthealveoliopen.Intrapleuralpressureisthepressurebetweentwolayersofpleura.Itisabout-5cmH2Obeforethestartofinspirationorattheendofexpiration.Alveolarpressureisthepressurewithintheterminalairspaces.Itisthesumofpleuralpressureandelasticrecoilpressureofthelung.Itisatmosphericbeforethestartofinspirationorattheendofexpiration.Transthoracicpressureisthepressuredifferencebetweenalveolarpressureandpressureatthebodysurface.Ref:FundamentalsofRespiratoryPhysiologyByASChakrabarty,Page32
19.Whatisthepartialpressureofoxygenat760mmHgatmosphericpressure? a)76 b)160 c)120 d)130 CorrectAnswer-BThepressureofagasisproportionaltoitstemperatureandthenumberofmolespervolume.P=nRT/V,where,n=numberofmolesP=PressureR=GasconstantT=AbsolutetemperatureV=VolumeThepressureexertedbyonegasinamixtureofgasesisequaltothetotalpressuretimesthefractionofthetotalamountofgasitrepresents.Thepartialpressureofoxygenindryairistherefore0.21x760=160mmofHgatsealevel. Ref:Ganong,23rdEd,Page588
20.Theprimaryactivestepforsodiumreabsorptionintheproximaltubule involves: a)Sodium-glucosecotransportacrosstheluminalmembrane b)Sodium/hydrogenioncountertransportacrosstheluminal membrane c)SodiumtransportviatheNa+-K+-ATPaseatthebasolateral membrane d)Sodium-aminoacidcotransportacrosstheluminalmembrane CorrectAnswer-C SodiumtransportviatheNa-K-ATPaseatthebasolateralmembrane.Thisistheonlytransportstepforsodiumintheproximaltubulethatinvolvesthedirectinputofenergytomovesodiumagainstitselectrochemicalgradient(inthiscasefromtheinsideofthecelltotheoutside).
21.AngiotensinIIcausesallofthefollowing,EXCEPT: a)Stimulationofthirst b)Aldosteronesecretion c)IncreasedADHsecretion d)Vasodilation CorrectAnswer-D"AngiotensinIIisoneofthemostpotentvasoconstrictorsknown,beingfourtoeighttimesasactiveasnorepinephrineonaweightbasisinnormalindividuals".Itproducesarteriolarconstrictionandariseinsystolicanddiastolicbloodpressure.-Ganong Italsoactsontheadrenalcortextoincreasesecretionofaldosterone.Itfacilitatesthereleaseofnorepinephrinebyadirectactiononpostganglionicsympatheticneurons,contractionofmesangialcellswitharesultantdecreaseinGFRandadirecteffectontherenaltubulestoincreaseNa+reabsorption.Itactsonthebraintoincreasewaterintake(throughsubfornicialorgan)andincreasethesecretionofvasopressinandACTH.
22.Whichofthefollowingisthecauseofnonshiveringthermogenesisinadults? a)Noradrenaline b)Thyroidhormone c)Musclemetabolism d)Brownfatbetweentheshoulders CorrectAnswer-ANonshiveringthermogenesisreferstoincreaseinmetabolicratethatisnotaresultofmuscleactivity.Itappearstobeelicitedthroughsympatheticstimulationandcirculatingcatecholamines.Epinephrineandnorepinephrinewhicharereleasedincreasesmetabolicactivityandheatgeneration.Ref:GuytonandHall-TextbookofMedicalPhysiology,10thEdition,Pages821,828-829;MedicalPhysiology:PrinciplesforClinicalMedicineByRodneyA.Rhoades,4thEdition,Page568;FundamentalsofHumanPhysiologyByLauraleeSherwood,Page489
23.ThenucleusinvolvedinPapezcircuitis: a)Pulvinar b)Intralaminar c)VPLnucleus d)AnteriornucleusofThalamus CorrectAnswer-DNucleusinvolvedinPapezcircuitisanteriornucleusofthalamus.Ref:ReviewofMedicalPhysiologybyWilliamganong,22ndEdition,Page256
24.WhichofthefollowingisNOTTRUEaboutCSF? a)RemovalofCSFduringduraltapcausesintenseintracranial headache b)Normallycontainnoneutrophils c)Formedbyarachnoidvilliwithintheventricles d)pHislessthanthatofplasma CorrectAnswer-CTheCSFisformedinthechoroidplexusesandtheremainderisformedaroundbloodvesselsandalongventricularwalls.CSFfillstheventriclesandsubarachnoidspace.Inhumans,thevolumeofCSFisabout150mLandtherateofCSFproductionisabout550mL/d.ThustheCSFturnsoverabout3.7timesaday.ThecompositionofCSFisessentiallythesameasthatofbrainextracellularfluid(ECF),whichinlivinghumansmakesup15%ofthebrainvolume.pH(7.31-7.34)slightlylessthanplasma(7.35-7.45).CSFcontainnoneutrophils.Itsdifferentialcountis:Lymphocyte-60-70%,Monocytes-30-50%,Neutrophils-None.Ref:BarrettK.E.,BarmanS.M.,BoitanoS.,BrooksH.L.(2012).Chapter33.CirculationthroughSpecialRegions.InK.E.Barrett,S.M.Barman,S.Boitano,H.L.Brooks(Eds),Ganong'sReviewofMedicalPhysiology,24e.
25.Cerebralbloodflowisregulatedbyall,EXCEPT: a)Intracranialpressure b)ArterialPC02 c)Potassiumions d)Cerebralmetabolicrate CorrectAnswer-CFactorsaffectingoverallcerebralbloodflowinclude: Intracranialpressure Localconstriction&dilationofcerebralarterioles Meanarterialpressureatbrainlevel Viscosityofblood MeanvenouspressureatbrainlevelThemostimportantextrinsicinfluencesonCBFarerespiratorygastensionsparticularlyarterialPC02.CerebralbloodflowisdirectlyproportionaltoarterialPC02betweentensionsof20and80mmofHg.Ref:BarrettK.E.,BarmanS.M.,BoitanoS.,BrooksH.L.(2012).Chapter33.CirculationthroughSpecialRegions.InK.E.Barrett,S.M.Barman,S.Boitano,H.L.Brooks(Eds),Ganong'sReviewofMedicalPhysiology,24e.
26.Withdrawalreflexisanexampleofwhichofthefollowing? a)Monosynapticreflex b)Polysynapticreflex c)BothAandBoftheabove d)Noneoftheabove CorrectAnswer-BThewithdrawalreflexisatypicalpolysynapticreflexthatoccursinresponsetoausuallypainfulstimulationoftheskinorsubcutaneoustissuesandmuscle.Whenareflexarcconsistsofonlytwoneuronsinananimal(onesensoryneuron,andonemotorneuron),itisdefinedasmonosynaptic.Monosynapticreferstothepresenceofasinglechemicalsynapse.Inthecaseofperipheralmusclereflexes(patellarreflex,achillesreflex),briefstimulationtothemusclespindleresultsincontractionoftheagonistoreffectormuscle.Inpolysynapticreflexpathways,oneormoreinterneuronsconnectafferent(sensory)andefferent(motor)signals.Allbutthemostsimplereflexesarepolysynaptic,allowingprocessingorinhibitionofpolysynapticreflexeswithinthebrain. Ref:Ganong'sReviewofMedicalPhysiology23rdedition,Chapter9.
27.Whichofthefollowingisreferredtoasthe"Windowofthe limbicsystem"? a)Hypothalamus b)Amygdala c)Hippocampus d)Thalamus CorrectAnswer-BAns.Bi.e.Amygdala.*Theamygdalahasbeencalledthe"window"throughwhichthelimbicsystemseestheplaceofthepersonintheworld.*Theamygdalareceivesneuronalsignalsfromallportionsofthelimbiccortex,aswellasfromtheneocortexofthetemporal,parietal,andoccipitallobes,especiallyfromtheauditoryandvisualassociationareas.
28.Broca'sareaisconcernedwith: a)Wordformation b)Comprehension c)Repetition d)Reading CorrectAnswer-AAi.e.WordformationWernicke'sarea-)Siteofintegration.Broca'sarea-+Motorpartofspeech.
29.Nucleusofbasalganglia a)Dentate b)Thalamus c)Caudate d)Rednucleus CorrectAnswer-CAns:Ci.e.CaudatenucleusThebasalgangliahavefivenucleioneachsideofthebrain.-Caudatenucleus-Putamen-Globuspallidus-Subthalamicnucleus-SubstantianigraThecaudatenucleusandputamencollectivelyformthestriatum.Theputamenandglobuspalliduscollectivelyformthelentiformnucleus.Theglobuspallidusisdividedintoexternalandinternalsegments
30.Restingmembranepotentialinnervefibre a)Isequaltothepotentialofventricularmusclefibre b)Canbemeasuredbysurfaceelectrodes c)IncreasesasextracellularK+increases d)DependsuponK+equilibrium CorrectAnswer-DDi.e.Dependsonpotassiumionequilibrium
31.AlveolarhypoventilationispresentinA/E: a)Bulberpoliomyelitis b)COPD c)Kyphoscoliosis d)Lobarpneumonia CorrectAnswer-DDi.eLobarPneumoniaTheimportantcausesofhypoventilation:-i)Obstructioninairways:-Foreignbody,COPD(chronicbronchitis,emphysema).ii)Decreaseinrespiratorydrive:-ItisduetodecreaseinstimulationofrespirationfromCNSe.g.braininjury,meningitis,bulbarpoliomyelitis,Drugs(morphine,sedative,anesthetics),hypothyroidism.iii)Decreaseinfunctioningofrespiratorymuscles:-Mystheniagravis,poliomyelitis,kyphoscoliosis,myopathy,polymyositis,GBsyndrome,interstitiallungdisorders,AML.iv)Increasedloadonrespiratorysystem:-Itmaybedueto:?a)Reducedchestwallcompliance:-Pleuraleffusion,pneumothorax,ascitis,ribcagedisorder(kyphoscoliosis),ankylosingspondylitis.b)Reducedlungcompliance:-Atelectasis,lungresection,alveolaredema,PEEP.
32.WhichofthefollowingdoesNOT stimulateperipheralchemoreceptors: a)Hypoxia b)Hypocapnia c)Acidosis d)Lowperfusionpressure CorrectAnswer-BBi.e.Hypocapnia
33.Stabilityofalveoliismaintainedby? a)Lungcompliance b)Negativeintrapleuralpressure c)Increaseinalveolarsurfaceareabythesurfactant d)Residualairinalveoli CorrectAnswer-CCi.e.Increaseinalveolarsurfaceareabythesurfactant
34.Meanarterialpressureiscalculatedas: a)(SBP+2DBP)/3 b)(DBP+2SBP)/3 c)(SBP+3DBP)/2 d)(DBP+3SBP)/2 CorrectAnswer-AAi.e.(SBP+2DBP)/3
35.Cerebralbloodflowisregulatedbyall except: a)Bloodpressure b)ArterialPCO2 c)Potassiumions d)A&C CorrectAnswer-DAns.A&C.i.e.Bloodpressure&PotassiumionsThetotalcerebralbloodflowisheldconstantinfaceofconsiderablechangesinthesystemicbloodpressure(60-150mmHg)".-Principlesofmedicalphysiology."Cerebralbloodflowisnotaffectedoverafairlywidevariationinarterialbloodpressure".-RKMarya.Regulationofcerebralbloodflow:l)Autoregulation:-Duetotheinherentpropertyofbloodvessels,explainedbymyogenictheory.2)Metabolicregulation:CBFvariesdirectlywithmetabolicactivity.FactorsaffectingregulationarePCO2,PO2,K+,andadenosine.AmongthisPCO2isthemostimportantone.3)Sympatheticinnervation:-ImportantonlyincaseswithverysevereelevationofBBe.g.inverystrenuousexercises.4)Intracranialpressure:-ByCushingreflex.5)Others:Bloodviscosity.
36.Gastrinisproducedby: a)Pancreas b)Gastricantralcells c)Pituitary d)All CorrectAnswer-DDi.e.All
37.Gastricsecretionis: a)Inhibitedbycurare b)Stimulatedbynoradrenaline c)Increasedbystomachdistention d)Stimulatedbyanincreaseintonicactivity CorrectAnswer-CCi.e.Increasedbystomachdistension
38.Whichinhibitsgastricsecretion? a)Secretin b)Insulin c)HighgastricpH d)Calcium CorrectAnswer-AAi.e.SecretinGastrinisahormonewhichisproducedbyG-cellsinthelateralwallofglandsintheantralportionofgastricmucose.Itisalsofoundinpancreaticisletsinfetallife,gastrinomasofpancreas,andpituitaryglandQ,hypothalamus,medullaoblongataandinvagus&sciaticnerves.
39.Pancreaticjuicerichinwaterand electrolytespoorinenzymesissecretedinresponseto: a)Pancreatozymin b)Cholecystokinin c)Secretin d)Proteins CorrectAnswer-CCi.e.Secretin
40.Smallintestinalperistalsisiscontrolledby : a)Myentricplexus b)Meissnersplexus c)Vagusnerve d)Parasympatheticsystem CorrectAnswer-AAi.e.MyentricplexusMyenteric(Auerbach's)plexusissituatedb/wandinnervatesouterlongitudinal&middlecircularmuscularlayersandisprimarilyconcernedwithmotorcontrolQ.Submucosal(meissner's)plexussituatedbetweenmiddlecircularlayerandmucosaisprimarlyconcernedwithcontrolofintestinalsecretionQasitinnervatesglandularepithelium,intestinalendocrinecells&submucosalbloodvessels.
41.Ovarianreserveisbestindicatedby a)LH b)FSH c)LH/FSHratio d)Estrogen CorrectAnswer-BBi.e.FSHOvarianreservecanbebestassessedbymeasuringFSHlevelson3rddayofmenstrualcycle,clomiphenecitratechallenge/provocativetest(measuresFSHlevelsoncycleday10afterantiestrogenclomiphenecitrate100mgadministrationfromday5to9).SeruminhibinBlevelandultrasonicscanningtocountthenumberofantralfolliclesinovaryareothermethods.OvarianReserve-Itreferstothesizeofresting/nongrowing/primordialfolliclepopulation,whichreflectsthequantity(no)ofgrowingfolliclesandqualityofoocyteswithinit.Soovarianreservedeterminesthefunctionalreproductivepotentialofovary.-UndertheinfluenceofFSHandLH,thereisrapidgrowthofseveralfolliclesinovary,duringfirstfewdaysofeachmenstrualcycle.Butafteraweekonly1folliclebeginstooutgrowalltheothers/whichinvolutebyaprocesscalledatresiaandthuspreventingmorethanonechildfromdevelopingwitheachpregnancy).-Ovarianreserve(&capacityofovarytoproduceeggs)declinewithadvancingage.Bestpredictorofovarianreserveisage.Teststhatcandetermineovarianreserveinclude
42.
Whichoftheseisnotapartofextracellularmatrix: a)Laminin b)Fibronectin c)Integrins d)Collagen CorrectAnswer-CCi.e.Integrins-Extracellularmatrixproteinsarecollagen,elastin,fibrillin,fibronectin,lamininandproteoglycans(GAGs)Mn-"CallElaForLastProse"Whereascelladhesionmoleculespresentincytoplasmorcellmembraneincludeintegrins,selectins,cadherinsandimmunoglobulinfamilyCAMsQ.-Integrinsarecellsurfaceadhesionproteinthatprovidelinkagebetweencelloutside&inside,betweencell-cellandbetweencell&extracellularmatrix.
43.Allofthefollowingoccurinmitochondria except a)Citricacidcycle(Kreb'scycle) b)Glycogenolysis c)Fattyacidoxidation d)Electrontransportchain CorrectAnswer-BBi.e.Glycogenolysis
44.QRScomplexisdueto: September2008 a)Ventricularrepolarization b)Atrialdepolarization c)ConductionthroughAVnode d)Ventriculardepolarization CorrectAnswer-DAns.D:VentriculardepolarizationQRScomplexisduetoventriculardepolarizationandatrialrepolarization.Normaldurationis0.08sec.
45.Coronarybloodflowismaximumduring whichphaseofcardiaccycle: a)Isovolumicrelaxationphase b)Isovolumiccontractionphase c)Ejectionphase d)Isovolumiccontractionphase CorrectAnswer-AAns.A:IsovolumicrelaxationphaseMaximumcoronarybloodflowoccursduringthephaseofisovolumetricventricularrelaxationphaseIsovolumetric/isometricrelaxationtime/IVRTAnintervalinthecardiaccycle,fromtheaorticcomponentofthesecondheartsound,thatis,closureoftheaorticvalve,toonsetoffillingbyopeningofthemitralvalve.Ventricularpressuredecreasestozerorapidlywhileaorticpressuredecreasesonlyto80mmHgi.e.itremainsfairlyhigh.Therefore,intramyocardialcompressionofbloodvesselsisminimalandperfusionpressureismaintainedfairlyhigh.SocoronarybloodflowrisessharplyMaximumcoronarybloodflowoccursduringthisphaseItcanbeusedasanindicatorofdiastolicdysfunction.ProlongedIVRTindicatespoormyocardialrelaxation.AnormalIVRTisabout70?12ms,andapproximately10mslongerinpeopleoverfortyyears.Inabnormalrelaxation,IVRTisusuallyinexcessof110ms.Withrestrictiveventricularfilling,itisusuallyunder60ms
46.Aorticvalveclosurecorrespondstothe beginningof:September2011 a)Systole b)Parasystole c)Isovolumetricrelaxation d)Isovolumetriccontraction CorrectAnswer-CAns.C:IsovolumetricrelaxationCardiacDiastoleItistheperiodoftimewhentheheartrelaxesaftercontractioninpreparationforrefillingwithcirculatingblood.Duringventriculardiastole,thepressureinthe(leftandright)ventriclesdropsfromthepeakthatitreachesinsystole.Whenthepressureintheleftventricledropstobelowthepressureintheleftatrium,themitralvalveopens,andtheleftventriclefillswithbloodthatwasaccumulatingintheleftatrium.Theisovolumicrelaxationtime(IVRT)istheintervalfromtheaorticcomponentofthesecondheartsound,thatis,closureoftheaorticvalve,toonsetoffillingbyopeningofthemitralvalve.Likewise,whenthepressureintherightventricledropsbelowthatintherightatrium,thetricuspidvalveopens,andtherightventriclefillswithbloodthatwasaccumulatingintherightatrium.Duringdiastolethepressurewithintherightventricleislowerthanthatinaorta,allowingbloodtocirculateintheheartitselfviathecoronaryarteries.
47.Chymotrypsinogenisactivatedinto chymotrypsinby: a)Trypsin b)Pepsin c)Renin d)HCl CorrectAnswer-AAns.A:TrypsinTrypsinissecretedintotheduodenum,whereithydrolyzespeptidesintoitssmallerbuildingblocks,namelyaminoacids.Trypsincatalyzesthehydrolysisofpeptidebonds.TrypsinshaveanoptimaloperatingpHofabout8.Trypsinsareconsideredendopeptidases,i.e.,thecleavageoccurswithinthepolypeptidechainratherthanattheterminalaminoacidslocatedattheendsofpolypeptides.Trypsinisproducedinthepancreasintheformofinactivetrypsinogen.Itisthensecretedintothesmallintestine,wheretheenzymeenteropeptidaseactivatesitintotrypsinbyproteolyticcleavage.Theresultingtrypsinsthemselvesactivatemoretrypsinogens(autocatalysis),chymotrypsinogen,Elastase/proelastase,CarboxypeptidaseAandB,ColipaseandPhospholipaseA2.
48.Shiveringiscontrolledby: September2012,March2013 a)Dorsomedialnucleus b)Posteriorhypothalamus c)Perifornicalnucleus d)Lateralhypothalamicarea CorrectAnswer-BAns.Bi.e.PosteriorhypothalamusShivering/ShudderingItisabodilyfunctioninresponsetoearlyhypothermiainwarm-bloodedanimals.Whenthecorebodytemperaturedrops,theshiveringreflexistriggeredtomaintainhomeostasis.Musclegroupsaroundthevitalorgansbegintoshakeinsmallmovementsinanattempttocreatewarmthbyexpendingenergy.Shiveringcanalsobearesponsetoafever,asapersonmayfeelcold,thoughtheircoretemperatureisalreadyelevated.Locatedintheposteriorhypothalamusnearthewallofthethirdventricleisanareacalledtheprimarymotorcenterforshivering.Thisareaisnormallyinhibitedbysignalsfromtheheatcenterintheanteriorhypothalamic-preopticareabutisexcitedbycoldsignalsfromtheskinandspinalcord.
49.Vomitingcentreissituatedinthe: September2008 a)Hypothalamus b)Midbarin c)Pons d)Medulla CorrectAnswer-DAns.D:MedullaVomitingisbelievedtobecontrolledbytwodistinctbraincentres--thevomitingcentreandthechemoreceptortriggerzone--bothlocatedinthemedullaoblongata.Thevomitingcentreinitiatesandcontrolstheactofemesis,whichinvolvesaseriesofcontractionsofthesmoothmusclesliningthedigestivetract
50.Bohreffectisdescribedas: September2009 a)DecreaseinCO2affinityofhemoglobinwhenthepHofblood rises b)DecreaseinCO2affinityofhemoglobinwhenthepHofblood falls c)DecreaseinO2affinityofhemoglobinwhenthepHofblood rises d)DecreaseinO2affinityofhemoglobinwhenthepHofblood falls CorrectAnswer-DAns.D:DecreaseinO2affinityofhemoglobinwhenthepHofbloodfallsThedecreaseinO2affinityofhemoglobinwhenthepHofbloodfallsiscalledtheBohreffectandiscloselyrelatedtothefactthatdeoxygenatedhemoglobin(deoxyhemoglobin)bindsH+moreactivelythandoesoxyhemoglobin.ThepHofbloodfallsasitsCO,contentincreases,sothatwhenthePCO2rises,thecurveshiftstotherightandtheP5,,rises.
51.FALSEforseminalvesicles: September2012 a)Containslargeamountoffructose b)Storessperms c)Situatedoneithersidenearprostate d)Secretionofseminalvesiclegivesmucoidconsistencyto semen CorrectAnswer-BAns.Bi.e.StoresspermsSpermsarestoredinepididymis
52.Whichofthefollowingareinactiveduring normalrespiration? a)Pre-Botzingercomplex b)Dorsalgroupofneurons c)VentralVRGgroupofneurons d)Pneumotaxiccenter CorrectAnswer-CAns.is'c'i.e.,VentralgroupofneuronsMedullaryrespiratorycentersTheprincipalareasinthemedullaoblongataconcernedwithregulationofrespirationare:?1)Dorsalrespiratorygroup(DRG):-Thedorsalrespiratorygroupofneuronsaremainlyconcernedwithinspiration.Theydescendandterminateonspinalmotorneuronsinnervatingtheprimarymusclesofinspiration,i.e.,thediaphragmandtheexternalintercostalmuscles.2)Ventralrespiratorygroup(VRG):-Theventralrespiratorygroupofneuronsismainlyconcernedwithforcefulexpirationbutalsoshowssomeactivityduringinspiration.Therefore,theseneuronscontributetobothexpirationandinspiration.Theseneuronsaredividedinto:?i)TherostralVRGneurons:-Theseneuronsshowactivityprimarilysynchronouswithinspirationandthereforebecalledinspiratory(I)neurons.Theyterminateonspinalmotorneuronssupplyingtheaccessorymusclesofinspiration,i.e.,sternocleidomastoid,scalenesandanteriorserrati.ii)TheventralVRGneurons:-Thesearemostlyexpiratory(E)neurons.Butsincetheexpirationisgenerallyapassiveprocess,E
neuronsaresilentmostofthetime.However,theseneuronsshowactivitywhenexpirationisforceful,asduringexercise.Theseneuronsterminateonspinalmotorneuronssupplythemusclesofexpiration,i.e.,internalintercostalandabdominalmuscles.3)Pre-Botzingercomplex:-Theseneuronsareresponsibleforgenerationofrespiratoryrhythm,i.e.,thepacemakercellswhichregulatetherateofrespirationarelocatedinPre-Botzingercomplex.PontinerespiratorycentersTheimportantpontineareasconcernedwithrespirationare:?1)Pneumotoxiccenter(nucleusparabrachialismedialis):-Itislocatedinupperpartofponsandtransmitssignalstotheinspiratoryarea.Thefunctionofthepneumotaxiccenterisprimarilytolimitinspiration,i.e.,theprimaryeffectofthiscenteristocontrolthe"switch-off"pointoftheinspiratoryrampthuscontrollingthedepthofinspiration,i.e.,thedurationofthefillingphaseofthelungcycle.Pneumotaxiccenteralsoinhibitsapneusticcenterfurtherinhibitinginspiration.Thereforestrongstimulationofthiscenterresultsinanearlyterminationofinspiratoryrampandhence,inspirationisshortenedandthetidalvolumedecreases.Conversely,intheabsenceofinputsfromthiscenter,inspiratoryrampcontinuesmuchlongerandhenceinspirationisprolongedandthetidalvolumeincreases.2)Apneusticcenter:-Thiscenterlocatedinthelower(caudal)partofpons.Theapneusticcenterexcitesinspiratorycenter(DRG)andproduceaprolongedinspiratorydrivewhichdelaystheonsetofexpiration.Thus,thoughtherespiratoryrhythmisestablishedinthemedulla,thisrhythmisspoiltbyastronginspiratorydriveorginatingintheapneusticcenters.However,twoinfluencesseemstokeeptheapneusticcenterincheck:(i)Pneumotaxiccenterofupperponsand(ii)Influencefromstretchreceptorsinlungviavagus.Bothoftheseinfluenceinhibitinspiratoryactivity.
53.Sleepcentreislocatedin- a)Basalganglia b)Medulla c)Hypothalamus d)Cerebellum CorrectAnswer-CAns.is'c'i.e.,Hypothalamus
54.Aromataseproducesestrogenfrom- a)Progesterone b)Cortisol c)Aldosterone d)Androgen CorrectAnswer-DAns.is'd'i.e.,Androgen
55.Actionofprogesterone? a)Increasedsensitivityofuterustooxytocin b)InhibitsLHsecretion c)Decreaseinbodytemperature d)Causesproliferativechangesinuterus CorrectAnswer-BAns.is'b'i.e.,InhibitsLHsecretion
56.Corpusleuteumstartsregressingafter howmanydaysofovulation? a)5days b)10days c)24days d)None CorrectAnswer-BAns.is'b'i.e.,10daysIfovumisnotfertilized,thecorpusluteumstartsdegeneratingaroundday24ofcycle(about10daysafterovulation)andiseventuallyisreplacedbyfibroustissue,formingcorpusalbicans.DegenerationofcorpusluteumisduetodeclineinlevelofLH(whichisrequiredformaintenanceofcorpusluteum)andincreaseinsecretionofinhibinbylutealcellitself.
57.WeberFechnerlawisrelatedto? a)Phantomlimb b)Forceofcontractioninheart c)Intensityofstimulusandsensationfelt d)Corticalplasticity CorrectAnswer-CAns.is'c'i.e.,Intensityofstimulusandsensationfelt
58.MaximumamountofK+ionisseenin whichGIsecretion? a)Saliva b)Colonic c)Gastric d)Jejunal CorrectAnswer-AAns.is'a'i.e.,Saliva
59.Bloodsupplyofbrainis? a)1500ml/min b)2000ml/min c)750ml/min d)250ml/min CorrectAnswer-CAns.is'c'i.e.,750ml/minThecerebralbloodflow(CBF)isabout750ml/min(15%oftotalcardiacoutput),or54ml/100gmbraintissueperminute.
60.Fertilizationtakesplaceafterhowmuch timeofovulation? a)1-2days b)5-6days c)8-12days d)>12days CorrectAnswer-AAns.is'a'i.e.,1-2days
61.Majorneurotransmitterinafferentsin nucleustractussolitariustoregulatecardiovascularsystem? a)Serotoxin b)Glutamate c)Glycine d)Norepinephrine CorrectAnswer-BAns.is'b'i.e.,GlutamateNucleustractussolitarius(NTS)liesinmedulla.Itreceivesfollowingafferents:?A)Generalvisceralafferentsi)Fromtonsil,pharynx,posteriorpartoftongue,carotidbodyandsinusthroughglossopharyngealnerve.ii)Frompharynx,larynx,trachea,esophagus,andotherthoracicandabdominalviscerathroughvagusnerve.B)Specialvisceralafferentsi)Fromanterior2/3oftongue(exceptcircumvallatepapillae)andpalatethroughfacialnerveii)Fromposterior1/3oftongue(includingcircumvallatepapillae)throughglossopharyngealnerve.iii)Fromposteriormostpartoftongueandepiglottisthroughvagusnerve.NTSisinvolvedinregulationofcardiovascularsystemthroughbaroreceptorsandchemoreceptors.Thereisageneralconsensusthatglutamateistheneurotransmitterreleasedatthetherminalsofbaroreceptorandchemoreceptor
afferentsinNTS.--www.springer.comHowever,cholinergic,GABAergic,andopioidergicmechanismsarealsopresentinNTS.
62.Mostdiffusibleionacrossmembrane- a)Na+ b)K+ c)Cl- d)None CorrectAnswer-CAns.is'c'i.e.,Cl?Amongthegivenoptions,Cl-haslowestpermeabilitycoefficientandmaximumpermeability.PermeabilityofmembraneAsthemajormiddleportionofmembrane(coreofthemembrane)isformedbyhydrophobicregionofphospholipids,thisportionisimpermeabletotheusualwater-solublesubstances,suchasions,glucoseandurea.Conversely,fat-solublesubstances,suchasoxygen,carbondioxide,andalcohol,canpenetratethisportionofthemembranewithease.Thepermeabilitycoefficientsofsmallmoleculesinthelipidbilayercorrelatewiththeirsolubilitiesinnonpolar(hydrophobic)regionandthustheirpermeability.
63.Cellsmostsensitivetohypoxiaare? a)Myocardialcells b)Neurons c)Hepatocytes d)Renaltubularepithelialcells CorrectAnswer-BAns.is'b'i.e.,NeuronsThesusceptibilityofatissuetohypoxiainfluencesthelikelihoodofinfarction.Neuronsaremostsensitivetohypoxia(irreversiblechangesdevelopin3-4minutes)followedbymyocardialcells(irrversiblechangesdevelopin20-40minutes).Fibroblastsareamongstthemostresistentcellstohypoxia.
64.Beta-2transferrinisfoundin? a)Blood b)Urine c)Tear d)CSF CorrectAnswer-DAns.is'd'i.e.,CSFBeta-2transferrinisanisoformoftransferrin.Itisfoundincerebrospinalfluid(CSF).Itisnotfoundinotherbodyfluids(blood,mucus,tear,saliva,urine).Therefore,itisaspecificmarkerforCSFandisusedfordiagnosticofCSFleaks.
65.Whatwilloccurwithincreaseinalveolar ventilationrate? a)DecreasedpartialpressureofO2inalveoli b)DecreasedpartialpressureofCO2inalveoli c)DecreasedCO2diffusionfrombloodtoalveoli d)DecreasedO2diffusionfromalveolitoblood CorrectAnswer-BAns.is'b'i.e.,DecreasedpartialpressureofCO2inalveoliAlveolarventilationistheamountofinspiredairenteringingas-exchangeareas(alveoli)perminuteduringquitebreathing.Itexcludestheairwhichremainsindeadspace.
66.Toneofloweresophagealsphincteris increasedby? a)NO b)VIP c)Acetylcholine d)Epinephrine CorrectAnswer-CAns.is'c'i.e.,AcetylcholineLoweresophagealsphincterUnliketherestoftheesophagus,themusculatureofthegastroesophagealjunction(loweresophagealsphincter;LES)istonicallyactivebutrelaxesonswallowing.ThetonicactivityoftheLESbetweenmealspreventsrefluxofgastirccontentsintotheesophagus.oTheLESismadeupofthreecomponents.Theesophagealsmoothmuscleismoreprominentatthejunctionwiththestomach(intrinsicsphincter).Fibersofthecruralportionofthediaphragm,askeletal,askeletalmuscles,surroundtheesophagusatthispoint(extrinsicsphincter)andexertapinchcock-likeactionontheesophagus.Inaddition,theobliqueorslingfibersofthestomachwallcreateaflapvalvethathelpscloseofftheesophagogastricjunctionandpreventregurgitationwhenintragastricpressurerises.ThetoneoftheLESisunderneuralcontrol.Releaseofacetylcholinefromvagalendingscausestheintrinsicsphinctertocontact,andreleaseofNOandVIPfrominterneuronsinnervatedbyothervagalfiberscausesittorelax.Contractionofthecruralportionofthediaphragm,whichis
innervatedbythephrenicnerves,iscoordinatedwithrespirationandcontractionsofchestandabdominalmuscles.Thus,theintrinsicandextrinsicsphinctersoperatetogethertopermitorderlyflowoffoodintothestomachandtopreventrefluxofgastriccontentsintotheesophagus.
67.Whilewalkingorstanding,postureis maintainby? a)Basalganglia b)Hypothalamus c)Cerebellum d)Amygdala CorrectAnswer-CAns.is'c'i.e.,CerebellumCerebellum,throughitsconnectionwiththerednucleusinfluencestheactivityofbrainstemreticularformationandtherebygammamotorneuronactivity.Throughitsconnectionswiththevestibularnucleusandvestibulospinaltract,cerebelluminflunencestheactivityofalphamotorneurons.Thus,normalcerebellarfunctionisessentialforthemaintenanceofnormalmuscletoneandposture.Thecerebellumseemstoplaycrucialrolesinwalkingaswellasmaintaingastandingposture.Cerebellarvermisplaysanimportantroleinmaintenanceofstandingpostuk.Basalgangliaisalsoinvolvedinmaintainingposturebyactingasrelaycenterforextrapyramidalpathways.Butitsroleisnotasimportant.
68.Pepsinogenisactivatedby? a)Enterokinase b)Enteropeptidase c)H+ d)Trypsin CorrectAnswer-CAns.isci.e.,H+Pepsinissecretedbychiefcellsofstomachinaninactive(zymogen)formcalledpepsinogen.Acid(IF)inlumenofstomachconvertspepsinogentoactivepepsin.Pepsinonceformedalsoattackspepsinogenproducingmorepepsinmoleculesbyautocatalysis.
69.Bileacidhasadetergentactiondueto? a)Formationofsoap b)Formationofzwitterion c)Amphipathicnatureofbilesalts d)Formationofmediumchaintriglycerides CorrectAnswer-CAns.isci.e.,AmphipathicnatureofbileacidsBile-saltshelpindigestionoffatbyemulsificationoffatinsmallintestinebydetergentactionofbilesalts.Thedetergentactionofbilesaltsisduetotheiramphipathicproperty.Emulsificationincreasesthesurfacetovolumeratioofthelipiddropletsfacilitatingtheactionoflipases.Bilesaltsalsohelpinformationofmicelles.Micellarformationsolubilizesthedigestedfatsandprovidesamechanismoftheirabsorptionintotheenterocytes.
70.Myelinationinperipheralnervoussystem isdoneby a)Astrocytes b)Oligodendrocytes c)Ependymalcells d)Schwanncells CorrectAnswer-DAns.isdi.e.,SchwanncellsMyelinationincentralnervoussystemOligodendrocytes.MyelinationinperipheralnervoussystemSchwanncell.
71.Digestionofdisaccharidesoccursat? a)Mouth b)Stomach c)Smallintestine d)Largeintestine CorrectAnswer-CAns.is'c'i.e.,SmallintestineDigestionofdisaccharides(maltose,sucroseandlactose)occursbytheenzymespresentinbrushborderossmallintestinalepithelialcells.Maltase(a-glucosidase)breaks1:4linkagesinmaltoseandmaltotrioseandreleasesglucose(twomoleculesofglucosefrommaltoseandthreemoleculesofglucosefrommaltotriose).Isomaltase(a-limitdextrinase)breaks1:6alinkagesofalpha-limitdextrinandreleasesglucose.Isomaltasedextrinase)istheonlyenzymethatattacks1:6alinkage.Sucroseishydrolysedintofructoseandglucosebysucrase(anenzymepresentinbrushborderofintestinalepithelium).Lactoseishydrolysedintogalactoseandglucosebylactase((3-glucosidase).Trehalasehydrolyzestrehelose(a1:1a-linkeddimerofglucose)intotwoglucosemolecules.Trehaloseisfoundinmushrooms.
72.Dicroticnotchiscausedby a)Closureofmitralvalve b)Openingofmitralvalve c)Closureofaorticvalve d)Openingofaorticvalve CorrectAnswer-CAns.is'c'i.e..ClosureofaorticvalveAorticpressurecurveWiththeonsetoftherapidejectionphaseoftheventricularsystole,theaorticpressurerisessteeplytoreachamaximumofabout120mmHg.Theejectionofbloodintotheaortacausesastretchontheaorticwallsandmakesthebloodintheentirearterialsystemtomoveatafasterrate.Thissetsupapressurewavethattravelsalongthearteries.Thepressurewaveexpandsthearterialwallasittravels,andexpansionispalpableasthepulse.Inthelaterpartoftheventricularsystole,theaorticpressuredeclinesandcontinuestodeclinethroughoutthediastole,toreachaminimumofabout80mmHgduringtheisometriccontractionofthenextcardiaccycle.Theelasticrecoiloftheaortaandtheresistanceofarterioleshelptomaintainrelativelyhighaorticpressureduringdiastole.Anotch(incisuraordicroticnotch)isrecordedintheearlypartofthedownstrokeoftheaorticpressurecurve.Itcorrespondstotheclosureoftheaorticvalve.Itisproducedbythesuddenbackwardflowofaorticbloodfollowedbytheimmediatecessationofbackflowduetoclosureoftheaorticvalves.
73.Whichofthefollowingisanexampleof activetransport? a)Movementofwateracrosscellmembrane b)Movementofoxygenacrosscellmembrane c)Co-transportofaminoacidswithsodium d)Noneoftheabove CorrectAnswer-CAns.is'C'i.e.,Co-transportofaminoacidswithNa+ActivetransportofNa+andK+isoneofthemajorenergy-usingprocessesinthebody.TheactivetransportofNa+iscoupledtothetransportofothersubstances(secondaryactivetransport).Forexample,theluminalmembranesofmucosalcellsinthesmallintestinecontainasymportthattransportsglucoseintothecellonlyifNa+bindstotheproteinandistransportedintothecellatthesametime.
74.Chlorideshiftisdueto? a)GenerationofHCO-3inRBCs b)MetabolismofglucoseinRBCs c)FormationofO2-HbcomplexinRBCs d)None CorrectAnswer-AAns.is'a'i.e.,GenerationofHCO-3inRBCsCarbondioxideistransportedinbloodasplasmabicarbonate.Redbloodcells(RBCs)playamajorroleinthemechanismbecauseRBCscontaintheenzymecarbonicanhydrasethatcatalyzesthereactionCO2+H2O=HCO3+HencewhenCO2diffusesintotheRBC,itreactschemicallywithwatertogenerateHCO3-.Theftionsaremoppedupbyhemoglobin,whichisanexcellentbuffer.Thisenablesthereactiontoproceedintheforwarddirection.TheHCO3-ionsgenerateddiffuseoutintotheplasmainexchangeforCl-ionsthatdiffuseintoRBCssimultaneously.ThemovementofchlorideionsintoRBCiscalledChlorideshift.TheaboveeventsresultsinanincreaseintotalnumberionsinsidetheRBC,whichincreasesitsosmolarity.Asaresult,waterenterstheRBCthroughosmosis.TheRBCscarryingCO2inbicarbonateformwillthereforebesomewhatlargerthannormal.Hencethehematocritofvenousbloodisnormally3%greaterthanthatofarterialblood.oInthelungs,Cl-movesoutoftheRBCsandtheyshrink.
75.Whichofthefollowingispassively absorbedingut? a)Glucose b)Lipids c)Fructose d)Amino-acids CorrectAnswer-BAns.is'b'i.e.,Lipids
76.Pulmonaryvasodilatationiscausedby? a)Hypoxia b)ThromboxaneA2 c)Histamine d)Angiotensin-II CorrectAnswer-CAns.is'c'i.e.,Histamine
77.LifespanofneonatalRBC? a)60-90days b)90-120days c)120-150days d)150-200days CorrectAnswer-AAns.is'a'i.e.,60-90days
78.Skinbloodflowisdecreasedby? a)Dopamine b)Isoprenaline c)Noradrenaline d)Acetylcholine CorrectAnswer-CAns.is'c'i.e.,NoradrenalineAutophagyistheprocessbywhichcellssequesteranddegradetheirowncytoplasmicorganelles.Duringtheprocess,autophagicvacuoleisformed,whichisabilayervaculecontainingunnecessaryordysfunctionalorganelle.Autophagicvaculefuseswithlysosometoformautophagosome(autophagolysosome).Then,hydrolyticenzymesoflysosomedegradetheorganelleofautophagicvacuole.
79.Autophagicvacuolesfusewith? a)Golgicomplex b)ER c)Lysosome d)Mitocondria CorrectAnswer-CAns.is'c'i.e.,Lysosome
80.Feedforwardinhibitionsynapseseenin a)Medulla b)Cerebellum c)Basalganglia d)Hypothalamus CorrectAnswer-BAns.is`b'i.e.,CerebellumFeedforwardcontrolsystemisemployedduringtheregulationoftemperature.Infeed-forwardinhibition,aneuronisconnectedthroughtwopathwaysoneexcitatoryandoneinhibitory.Forexample,incerebellumthestimulationofBasketcellsproducesIPSPs(inhibitorypostsynapticpotentials)inPurkinjecells.However,thebasketcellsandthePurkinjecellsareexcitedbythesameparallel-fiberexcitatoryinput.Thisarrangementiscalledfeed-forwardinhibitionandhelpstopreventthedurationoftheexcitationproducedbyanygivenafferentimpulse.
81.Mainenzymeinvolvedindigestionoffatty food? a)Linguallipase b)Gastriclipase c)Pancreaticlipase d)Phospholipase CorrectAnswer-CAns.is'c'i.e.,PancreaticlipaseEbner'sglandsonthedorsumofthetonguesecretelinguallipaseandthestomachalsosecretesalipase(gastriclipase).However,theyareofverylittlesignificanceinfatdigestion.Fatdigestionessentiallybeginsintheduodenumwithentryofpancreaticandbiliarysecretions.oPancreaticjuicecontainslipase(pancreaticlipase),themostimportantenzymeforfatdigestion.Thepancreaticlipasedigeststriglycerides(triacylglycerols)intofreefattyacidsand2-monoglycerides(2?monocylglycerols).Pancreaticlipasehydrolyzes1-and3-bondsoftriglycerideswithrelativesparingof2-bonds,sotheprincipalproductsofitsactionarefreefattyacidsand2-monoglycerides.
82.Motorproteininorganofcorti? a)Kinesin b)Albumin c)Dynein d)Myosin CorrectAnswer-DAns.isdi.e.,MyosinTheinnerhaircellsoforganofcortihave50-200ciliatedstructurecalledstereocilia.Thetopofeachstereociliumislinkedtothesideofnextadjacenthigherstereociliumbymeansofathinfilamentousstrucuturecalledthetip-link.Mechanicallygatedionchannelsarelocatedattheseattachmentpointsonthesidesofstereocilia.Eachstereociliumcomprisesofseveralactinfilamentsencasedbyaplasmamembrane.Theopeningandclosingoftheionchannelsisaccomplishedthroughthebindingandunbindingofproteinsatterminalendsofthetiplinkswithagroupofchannelmotorproteins(myosin)whichmoveupanddowntheactinfilamentsofstereocilia.
83.Vibrationsarefeltby? a)Meissner'scorpuscle b)Merkel'sdisc c)Paciniancorpuscle d)Ruffini'sendorgan CorrectAnswer-CAns.is'c'i.e.,PaciniancorpuscleTactile(touch)receptorsThesearegeneralexteroreceptorsforepicriticsenses.Thesearedividedintosuperficialanddeepreceptors.Superficialreceptorsarepresentintheepidermisorpapillarylayerofdermis.Inglabrous(nonhairy)skinthesereceptorsareMerkel'sdisc(slowlyadapting)andMeissner'scorpuscle(rapidlyadapting).Inhairyskintherearehairfolliclereceptors.Deepreceptorsarepresentindeeperdermisorinthesubcutaneoustissues.ThedeepreceptorsaresameinbothhairandnonhairyskinandincludeRuffini'sendorgan(slowlyadapting)andPaciniancorpuscle(Rapidlyadapting).Touch,pressureandvibrationaredifferentformsofsamesensation.Pressureisfeltwhentheforceappliedontheskinissufficienttoreachthedeepreceptors,whereastouchisfeltwhentheforceisinsufficenttoreachthedeepreceptors,thereforedetectedbysuperficialreceptors(Merkel'sdisc,meissner'scorpuscle).Vibrationsarerhythmicvariationsinpressure(i.e.rhymicvariationsofforcethatreachesthedeepreceptors).Whetheratactilereceptorsensespressureorvibrationdependsonwhetherthereceptorisslowlyadaptingorslowlyadaping:?i)Slowlyadapting(Ruffini'sendorgan):-Aremeanttodetect
sustainedpressure;theyareuselessforvibrations.ii)Rapidlyadapting(Paciniancorpuscle):-Stopdischargeinresponsetosustainedpressure;theyareusefulonlywhenthepressurefluctuatesrapidly,i.e.duringvibrations.Thehighertherateofadaptationofareceptor,thegreateristhevibrationfrequencyitcandetect.Thus,tactile(touch)sensationcanbedividedinto:?A)Superficial(generallyconsideredastouch):-DetectedbyMeissner'scorpuscle(detecttextureofsurface,i.e.roughorsmooth)andMerkel'sdisc(detecttwopointdiscrimination).B)Deepi)Pressure(Deeptouch):-DetectedbyRuffini'sendorgan.ii)Vibrations:-DetectedbyPaciniancorpuscle
84.HerringBreuerreflexisanincreasein? a)Durationofinspiration b)Durationofexpiration c)Depthofinspiration d)Depthofexpiration CorrectAnswer-BAns.is'b'i.e.,DurationofexpirationTheHering-Breuerinflationreflexisanincreaseinthedurationofexpirationproducedbysteadylunginflation,andtheHering-Breuerdeflationreflexisadecreaseinthedurationofexpirationproducedbymarkeddeflationofthelung.
85.Amountofgastricjuicesecretedperday? a)500-1000ml b)1000-1500ml c)2000-2500ml d)3000-3500ml CorrectAnswer-CAns.is'c'i.e.,2000-2500ml
86.Trueaboutgapjunctionsareall,except? a)Transmitelectricsignals b)Allowionstopass c)Intercellularspace1000nm d)Seenincardiacmuscle CorrectAnswer-CAns.is'c'i.e.,Intercellularspace1000nmGapjunctionsareintercellularconnectionsconsistofapairofhemichannels(connexons)insertedintothemembraneofadjacentcells.Eachconnexoneismadeofsixidenticalproteinsubunitscalledconnexinswhichencloseacentralchannel.Whenthecorrespondingconnexonsofadjacentcelllinkupend-to-end,theyformacontinuouschannelthatpermitssubstancestopassthroughfromcelltocell.Atgapjunctions,theintercellularspacenarrowsdownto3nm,therebyhelpinginbindingthecellstogether.oHowever,theirrealphysiologicalsignificanceliesinallowingionstoflowthroughthem,i.e.theyconductioniccurrent.Thisenableselectricalexcitationtospreadfromcelltocell,asinsmoothandcardiacmuscles.TheporesizeofgapjunctionsdecreaseswhenintracellularCa'ishighorpHislow,bothofwhicharecommonlyassociatedwithcelldamage.ClosureofgapjunctionsinresponsetothesestimuliisolatesdamagedcellssothattheCa+2and1-1+donotspreadfromthedamagedtonormalcells.
87.Instarvation,earliesttobecomedepleted - a)Carbohydrates b)Proteins c)Fats d)None CorrectAnswer-AAns.is'a'i.e.,CarbohydratesMetabolicalterationduringfasting-starvationohemetabolicchangesobservedinfastingaregenerallyoppositetothosedescribedforabsorptive(fed)state.Intheabsenceoffood,plasmalevelsofglucose,aminoacids,andTGsfall,triggeringadeclineininsulinsecretionandanincreaseinglucagonrelease.Thisresultsindecreasedinsulin:glucagonratio.Whichisresponsibleformostofthemetabolicchanges.
88.Growthhormonesecretionisstimulated by? a)Increasedbloodglucose b)Decreasedbloodglucose c)Cortisol d)Somatostatin CorrectAnswer-BAns.is'b'i.e.,DecreasedbloodglucoseRegulationofGHsecretionGHsecretionisregulatedbyGHRHreleasedfromhypothalamus.GHissecretedinapulsatilefashionthroughoutthelife,withelevatedratesofsecretionimmediatelyafterbirthandatpuberty.Interestingly,largeburstsofsecretionoccuratnightduringtheonsetofdeepsleep.StimulithatincreasesecretionofGHarehypoglycemia,exercise,fasting,proteinmeals,aminoacids(likearginine),stress,glucagon,pyrogen,lysinvasopressin,apomorphins,L-dopa&a-adrenergics,estrogen,androgensand2-deoxyglucose.StimulithatdecreasesecretionofGHareREMsleep,glucose,Somatostatin,cortisol,FFA,GHitself,IGF-1,andmedroxyprogesteron.
89.Isocapnicexerciseis? a)Breathingforshortdurationagainstresistance b)Breathingofdecreasedvolumeofventilation c)Breathingofincreasedvolumeofventilationforlongperiod d)Breathingofdecreasedvolumeforlongperiod CorrectAnswer-CAns.is'c'i.e.,Breathingofincreasedvolumeofventilationforlongperiod
90.Hormonesrequiredduringpuberty? a)LSH b)Testesterone c)Leptin d)Alloftheabove CorrectAnswer-DAns.is'd'i.e.,AlloftheabovePubertyistriggeredbyareleaseofgonadotropins(FSHandLH)frompituitarygland.Thesehormonesactassignalstothegonads(testes/ovaries)thattriggertheproductionof-i)Estrogen,progesteroneandsometestosteroneinwomen.ii)Testosteroneinmen.Inbothmalesandfemales,testosteroneisresponsiblefordevelopmentofpubichair,acceleratedbonegrowth,bodyodorandacneduringpuberty.Forboys,testosteroneisresponsiblefortheprocessofvirilization,includingtheenlargementofthepenis,increasedlibidoandgrowthoffacialandchesthair.Estrogenisthemajorhormoneresponsibleforfemalepuberaldevelopment.Itcausesdevelopmentofbreastandthickeningofendometrium.Progesteronecausesproliferationofaciniinmammaryglandsandconvertswaterycervicalsecretiontoviscidandscanty.Leptinfacilitatesreleaseofgonadotropinreleasinghormone(GnRH),therebyhelpinginpubertalonset.Otherhormoneswhichareinvolvedinpubertyarethyroxineandgrowthhormone.
91.Capacitancevesselshaveintheirwall? a)Moreelastictissueandlessmuscle b)Lesselastictissueandmoremuscle c)Moreelastictissueandmoremuscle d)Lesselastictissueandlessmuscle CorrectAnswer-DAns.is'd'i.e.,LesselastictissueandlessmuscleVeinsarecapacitancevessels.Theyhavelesssmoothmuscleandlesselastictissueintheirwall.StructureofvesselsA)StructureofarteryItismadeupthreelayers-1.TunicaIntimaTheinnermostlayer(towardslumen)ofarteryisintima.Itconsistsofendothelialcellswhichrestonbasmentmembrane.Thereissomesubendothelialconnectivetissue.Intimaisseparatedfrommediabyinternalelasticlamina.2.TunicaMediaItismainlycontainssmoothmusclesandlaminaeofelastictissueMediaisseparatedfromadventitiabyexternalelasticlamina.3.TunicaAdventitiaItistheoutermostlayer.Containscollegenandelasticfibers.B)StructureofcapillariesCapillariesarethinwalledvesselsmadeupofsinglelayerofendothelialcellswithitsbasementmembrane.oCapillariesareofthreetypes-1.Continouscapillaries-Thesecapillarieshascontinuousliningofendothelialcellswithno
Thesecapillarieshascontinuousliningofendothelialcellswithnofenestration.Basementmembraneisalsocontinuous.2.FenesteratedcapillariesTherearefenestrationbetweentheendothelialcells.Basmentmembraneiscontinuous.3.SinusoidalcapillariesBothendothelialcellsandbasementmembranehavefenestration.Inrestingtissues,mostofthecapillariesarecollapsedandbloodflowsthroughthethroughfarevesselsfromthearteriolestothevenules.C)StructureofveinsStructureofveinissmiliartoarteryexceptthat-1.Wallisthinner2.Threetunicaearelesswelldemarcated.3.Elastictissueisscantyandnotclearlyorganizedintodistinctinternalandexternalelasticlamina.4.Havevalves(exceptvenaecavaeandcommoniliacvein).
92.EffectofcholecystokininonGIT? a)Increasesgastricacidsecretion b)Increasessmallintestinalperistlasis c)Increasesgastricmotility d)Relaxesgallbladder CorrectAnswer-BAns.is'b'i.e.,Increasessmallintestinalperistalsis
93.Pubarcheisdueto? a)GH b)Progesterone c)Testosterone d)Estrogen CorrectAnswer-CAns.is'c'i.e.,Testosterone
94.Falseabouttotalbodywater(TBW)? a)ICFis2/3rdofTBW b)InnewbornTBWis60%ofbodyweight c)PrematurenewbornshavemoreTBW d)Inadults,TBWis60%ofbodyweight CorrectAnswer-BAns.is'b'i.e.,InnewbornTBWis60%ofbodyweightInatermnewborn,TBWis70-80%ofbodyweight.Itismoreinprematurenewbornthanintermnewborn.Otheroptionsarecorrect.
95.Whichoffollowingisamicrofilament? a)Tubulin b)Actin c)Desmin d)Vimentin CorrectAnswer-BAns.is'b'i.e.,Actin
96.Allbelongtomolecularmotorfamily except? a)Kinesin b)Dynein c)Myosin d)Actin CorrectAnswer-DAns.is'd'i.e.,ActinMolecularmotorsMolecularmotorsareproteinwithATPaseorGTPaseactivitythatmoveorganelles,proteins,andothercomponentsofcelltoallpartsofthecells.Theseproteinsproduceforcemovementinwidevarietyofcellularprocessesincludingvesiculartransport,celldivision,nuclearmigration,musclecontraction,mechanochemicaltransductionandothers.Molecularmotorsuseenergytogeneratethisforce(molecularmotorsareATPase/GTPase).Importantcytoskeletalmolecularmotorsare:?i)Kinesin(anATPase):-InvolvedinaxoplasmictransportanduseshydrolysisofATPtomovevesiclesdowntheaxontowardthepositive(+)endofmicrotubuleformation.ii)Dynein(anATPase):-ItalsousesATP.therearetwotypesofdynein:?a)Cytosolicdynein:-Involvedinaxoplasmicflowtomovevesicleinoppositedirection,i.e.,towardsthenegativeendofmicrotubules.b)Axonemaldynein:-Powerciliaryandflagellarmovement.iii)Dynamin(aGTPase):-UsesGTPandisinvolvedinendocytosis.iv)Myosin(anATPase)UsesATPandisinvolvedinmusclecontractionbybindingwithactin.
97.Cellswhichsurroundtheoocystin graafianfolliclearecalled? a)Discusproligerus b)Cumulusoophoricus c)Lutealcells d)Villuscells CorrectAnswer-BAns.is'b'i.e.,CumulusoophoricusOocytelieseccentricallyinthegraafian(ovarian)follicle.Itissurroundedbysomegranulsacellsthataregiventhenamecumulusoophoriacus(orcumulusovaricus).Thecellsthatattachittothewallofthefolliclearegiventhenamediscusproligerus.
98.Followingchangesareseenduring capacitationofaspermsexcept? a)Increasedpermeabilitytocalcium b)Decreasedpermeabilitytocalcium c)Removalofcholesterolfromacrosome d)Increasedmotility CorrectAnswer-BAns.is'b'i.e.,DecreasedpermeabilitytocalciumCapacitationofsperm(spermatozoa)Spermatozoaleavingthetestis(seminiferousubules)arenotfullymobile.Theycontinuetheirmaturationandacquiretheirmobilityduringtheirpassagethroughepididymis.Fromepididymistheycometovasdeference,distalendofwhichalsoreceivesthesecretionsofseminalvesicle,andcontinuesastheejeculatoryduct.Theejeculatoryductjoinstheprostaticurethra.Onceejeculatedintothethefemale,vaginalsecretionsimprovethemotilityandfertilizingabilityofsperms.Furtherexposuretosecretionsoffemalegenitaltract(inuterusand/orfallopiantube)furtherimprovesthemobilityandfertilizingabilityofthesperms.Thebeneficialeffectsofstayinthefemalegenitaltractarecollectivelycalledcapacitation,fromtheisthmus,capacitatedspermsmoverapidlytotheampullas,wherefertilizationtakesplace.Followingchangesoccurduringcapacitation:-Uterineandfallopiantubefluidswashawaythevariousinhibitoryfactorsthatsuppressspermactivityinmalegenitaltract.Removalofcholesterolvesiclefromacrosomesothatacrosomalmembranebecomesweakandcanreleaseenzymeatthetimeoffertilization.
Increasemembranepermeabilitytocalciumion.
99.Mismatchofventilation/perfusionratiois seenin a)Apex b)Base c)Both d)None CorrectAnswer-CAns.is'C'i.e.,BothVentilationperfusionratio(V/O)oConsideringthatcardiacoutputis5.0L/minandalveolarventilationisabout4.2L/min,theoverallventilation:perfusionratiois0-8.Idealy,therefore,eachalveolusshouldhaveaV/Qratioof0.8.However,thatisnotsoeveninnormallungs.oDuetogravity,theapicalalveoliarebothunderventilatedandunderperfusedwhilethebasalalveoliarebothoverventilatedandoverperfused.However,gravityaffectsperfusionmuchmorethanitaffectsventilation.Hence,apicalalveoliaremoreunderperfusedthanunderventilatedwhilethebasalalveoliaremoreoverperfusedthanoverventilated.Therefore,V/Qismaximunatapex(about3-0)andleastatbase(about0-6).oSinceventilationisfarinexcessofperfusionatapex,comparativelylittleoxygenistransferredfromthealveolitotheblood,andCO2transferredtothealveoliisalsoless.Hencethegastensionattheapicesarequietclosetothoseofinspiredair,i.e.,HighPa02andlowPaCO2.Ontheotherhand,atthebaseoflungperfusionisbetterthanventilation;HencePa02andPaCO2ofbasalalveoliarequietclosetothoseofpulmonaryartery,i.e.,lowPaO,
andhighPaCO2.Insimplewords,ventilation-perfusionmismatchisresponsibleforhighP02withlowPCO2atapexandLowPO2withhighPCO2atbase.
100.Carotidandaorticbodiesarestimulated when? a)Oxygensaturationdecreasesbelow90% b)Oxygensaturationdecreasesbelow80% c)Oxygensaturationdecreasesbelow70% d)Oxygensaturationdecreasesbelow60% CorrectAnswer-AAns.is'a'i.e.,Oxygensaturationdecreasesbelow90%Peripheralchemoreceptors(carotidandaorticbodies)arestimulatedifarterialPO2isbelow60mmHg.AtPO2of60mmHg,O2saturationisabout90%(89%).
101.Senseorganwhichishavingefferent supply a)Golgitendonorgan b)Organofcorti c)Retina d)Tastebud CorrectAnswer-BAns.is'bi.e.,OrganofcortiAfferent(sensory)neuronscarryinformationformsenseorganstoCNS(brain&spinalcord).Haircells(inorganofcorti)arethesensoryreceporswhicharealsoinnervatedbyefferentneurons.
102.Falseregardingpapillaeoftongue? a)Fungiformpapillaeattip b)Circumvallatepapillaeatbase c)Foliatepapillaeatbackedge d)Filiformpapillaehavetastebudsattip CorrectAnswer-DAns.is'd'i.e.,FiliformpapillaehavetastebudsattipIntongue,tastebudsaregroupedinstructurescalledpapillae.Tastebudsarelocatedinthewallsofpapillae.Therearethreetypesofpapillae:-i)Fungiformpapillae:-Areespeciallynumerousnearthetipandthemarginsofthetongue.ii)Circumvallate(Vallate)papillae:-ThesearethelargestpapillaeandaredistributedtoaV-shapedregionnearthebaseoftongue.iii)Foliatepapillae:-Confinedtothebackedgeofthetongue.Besidesthesethreetypesofpapillae,thereisalsoafourthtype,thefiliformpapillaebutthesehavenotastebuds.
103.Electricpotentialofrestingmembrane foragivenelectrolyteisgivenbywhichequation? a)Nernst b)Goldman c)Donnan-Gibbs d)None CorrectAnswer-AAns.is'a'i.e.,Nernst
104.Incirculatorybiomechanicswhichofthe followingistrue? a)Bloodviscosityisincreasedinanemia b)Bloodviscosityisdecreasedinpolycythemia c)Cardiacoutputisincreasedinanemia d)CardiacoutputisdecreasedinBeri-Beri CorrectAnswer-CAns.is'c'i.e.,CardiacoutputisincreasedinanemiaCardiacoutputisincreasedinconditionswhichcausedecreaseinperipheralvascularresistance:-Exercise 1. AVfistulaorshunt2. Severeanemia3. Thyrotoxicosis4. Wetberi-beri5. Aboutotheroptions Bloodviscosityislowinanemiaandhighinpolycythemia.
105.Hemoglobinbinds/transportsallexcept? a)CO b)O2 c)SO2 d)CO2 CorrectAnswer-CAns.is'c'i.e.,SO2
106.Feverisproducedby? a)PGF2 b)PGE2 c)PGI2 d)PGD2 CorrectAnswer-BAns.is'b'i.e.,PGE2Feveriselevatedbodytemperatureduetoresettingofhypothalamicthermostatabovethenormallevel.IL-1(mostpotent),TNF-andIL-6arepyrogens(feverproducingcytokines).Buttheydonotactdirectly.TheystimulatethereleaseofPGE2,whichresetsthehypothalamicthermostatathigherlevel.Thus,PGE2isthefinaleffectorinproductionoffever.
107.Normalcapillarwedgepressure? a)0-2mmHg b)5-10mmHg c)15-20mmHg d)20-30mmHg CorrectAnswer-BAns.is'b'i.e.,5-10mmHgNormalcapillaryWedgepressureis4-12mmHg.Itisameasureofleftatrialpressure.
108.Insulinresistancedown-regulates- a)GLUT-1 b)GLUT-2 c)GLUT-3 d)GLUT-4 CorrectAnswer-DAns.is'd'i.e.,GLUT-4
109.Plateauofoxygen-hemoglobin dissociationcurvesignifies? a)NooxygenisavailableforbindingtoHb b)NoHbmoleculeisavailabletobindwithO2 c)Alloxygenisreleasedtotissues d)Noneoftheabove CorrectAnswer-BAns.is'b'i.e.,NoHbmoleculeisavailabletobindwithO2Eachmoleculeofhemoglobincancombinewithuptofourmoleculesofoxygen.Combinationwiththefirstmoleculealterstheconformationofthehemoglobinmoleculeinsuchawayastofacilitatecombinationwiththenextoxygenmolecule.Inlightofthis,ifwelookatthecurve,asthePO2startsrisingfrom0mmHgupwards,initiallyallhemoglobinmoleculesinbloodstartscombiningwiththeirfirstoxygenmolecule.Thisisthemostdifficultmoleculetocombinewith.HencesaturationrisesonlyslowlywithinitialriseinPO2.AsPO2risesfurther,hemoglobinmoleculescombinewiththeirsecond,thirdandfourthmolecules,whichareprogressivelyeasiertocombinewith.HencesaturationrisessteeplybetweenPO2of15mmHgand40mmHg.WhenPO2risesstillfurther,oxygenfindsmostofthehemoglobinmoleculescarryingfourmoleculesofoxygeneach.Sincenomoleculesofhemoglobincancarrymorethanfour
moleculesofoxygen,thereisnotmuchscopeformoreO2combiningwithhemoglobin.HencethecurvebecomesalmostflatagainbeyondthePO2of60mmHg.
110.Whichofthefollowingincreasesappetite ? a)CART b)-MSH c)AGPP d)Insulin CorrectAnswer-CAns.is'c'i.e.,AGPP
111.Trueaboutironabsorptionareall,except ? a)Majorsiteofabsorptionisduodenum b)StoredasFerritin c)Absorbedinferrousform d)Pancreaticsecretionsimprovestheabsorption CorrectAnswer-DAns.is'd'i.e.,PancreaticsecretionsimprovestheabsorptionIronabsorptionIronisabsorbedfromuppersmallintestinemainlyduodenum.Indietironoccursintwoforms,haemeironandinorganic(non-haeme)iron.Haemironisbetterabsorbedthaninorganiciron,butthemajorfractionofdietisinorganiciron.Inorganicironismostlyinferricform;needstobereducedtoferrousformbecauseironisabsorbedinferrousform.Afterabsorptionferrousformisonceagainoxidizedtoferricforminsideenterocytes.Afractionofabsorbedironisrapidlydeliveredtoplasmatransferrin.However,mostoftheironisdepositedintheenterocytesasferritin,sometobetransferredmoreslowlytoplasmatransferrin,andsometobelostwhensenescentmucosalcells(enterocytes)aresloughedintotheintestine.Ironabsorptionisregulatedaccordingtothedemand,e.g.,whenthereisirondeficiency,absorptionincreases.Thisregulationismediatedby"ironmetabolismregulatoryhormone",i.e.,hepcidinthatinhibitironabsorption.Whenthereisirondeficiency,concentrationofhepacidinfallsand
thereisincreaseironabsorption.Hepacidinalsodecreasesreleaseofironfromstoragesites.TransportandstorageofironIronistransportedisbloodincombinationwithaglycoproteintransferrin.Ironistransportedintocellsthroughattachmentoftransferrintospecificmembraneboundreceptors.Ironisstoredasferritin(majorstorageform)orhaemosiderin.Ferritinisacomplexofironandapoferritin(iron+apoferritinferritin).Ironismainlystoredinreticulo-endothelialcellsmonocytes/macrophagesofliver,spleen,bonemarrow.Itisalsostoredinhepatocytes(parenchymalcellsofliver)andmyocytesofskeletalmuscles.Note:Ironisstoredinferritininferricform.
112.Cardiacoutputincreasesby? a)Standingfromlyingdownposition b)Expiration c)Increasedcardiaccontractility d)Parasympatheticstimulation CorrectAnswer-CAns.is'c'i.e.,IncreasedcardiaccontractilityCardiacoutputistheproductofstrokevolumeandheartrate.Henceanyfactorwhichaffectseitherthestrokevolumeortheheartrateorbothaffectsthecardiacoutput.A)FactorsaffectingstrokevolumeStrokevolume,whichistheamountofbloodpumpedbytheheartduringonestroke,dependsmainlyonthreefactors:?Preload(Degreeofventricularfillingduringdiastole):-Cardiacpreloadisrepresentedbyvolumeofvenousbloodthatdistendstheventricle,i.e.,venousreturndeterminesthepreload.Anincreaseinpreload,i.e.,increaseinvenousreturnresultsinahigherend-diastolicvolume(Preload).ThisresultsinstretchingofmyocardialfiberandthisincreaseinlengthofmyofibrilincreasesthestrengthofcardiaccontractioninaccordancewiththeFrank-StarlinglaworStarling'slawoftheheart.AccordingtoStarling'slaw,greatertheinitiallengthofmusclefiber,greateristheforceofcontraction.Theinitiallengthofmusclefiber(lengthoffiberattheinitiationofcontraction/systole)referstolengthofthefiberattheendofthediastole,i.e.,end-diastolicfiberlength.Thus,thefactorswhichimprovevenousreturnincreasethecardiacoutputbyincreasingend-diastolicventricularvolumeandlength,i.e.,preload.Oppositeistrueforfactorswhichdecreasevenousreturn.
113.Spermatogenesistakesplacein? a)Epididymis b)Seminiferoustubule c)Ductusdeferens d)Prostate CorrectAnswer-BAns.is'b'i.e.,SeminiferoustubuleSpermatogenesisoccursinseminiferoustubules.Spermatogenesisreferstotheprocessofformationofspermatozoa(sperm)fromprimitivegermcells(spermatogonia).Stepsinspermatogenesisinvolve:?i)Spermatogonia(primitivegermcells)undergomitosistoformprimaryspermatocytes.Bothspermatogoniaandprimaryspermatocyteshavediploidchromosomes(46chromosomesordiploidof23chromosomes).ii)Primaryspermatocytesundergomeiosistoformsecondaryspermatocytes.Secondaryspermatocyteshavehaploid(23)chromosomes.iii)Secondaryspermatocytesundergomitosistoformspermatids.iv)Spermatidsdonotdividefurtherbutundergomorphologicalchangestoformsperms(spermatozoa).Thisstepofformationofspermatozoafromspermatidsiscalledspermiogenesis.Thespermiogenesistakesplaceinthedeepfoldsofcytoplasmofsertolicells.
114.EstrogenBetareceptorsarefoundon a)Uterus b)Bloodvessels c)Ovary d)Vagina CorrectAnswer-CAns.is'c'i.e.,Ovary
115.Endogenouspyrogensactby? a)Increasingheatgeneration b)Raisingthermostatpointofhypothalamus c)Causingvasoconstriction d)ByNon-shiveringthermogenesis CorrectAnswer-BAns.is'b'i.e.,RaisingthermostatpointofhypothalamusBacterialtoxins(exogenouspyrogens)stimulateinflammatorycellstosecretepyrogeniccytokines(endogenouspyrogens),e.g.IL-I,TNF-a,andIL-6.TheseendogenouspyrogenesstimulatePGE2releaseinhypothalamus,whichraisestemperaturesetpointofhypothalamustocausefever.
116.Extrinsicsystemofcoagulationis activatedby a)FactorXI b)FactorX c)FactorXII d)FactorIII CorrectAnswer-DAns.isdi.e.,FactorIII
117.Sharppainistransmittedbywhichtype offibres? a)A b)A c)A d)C CorrectAnswer-CAns.is'c'i.e.,ASharpsomaticpain(fastpain)iscarriedbyASfibres.Painiscarriedbytwotypesoffibers:?i)AThesearerelativelyfast.Thereforethepaincarriesbytheseisfastpain(epicriticpainorfirstpain).ii)CTheseareslow,thereforethepaincarriesbytheseisslowpain(protopathicpainorsecondpain).
118.Rewardcenterislocatedin? a)Cerebellum b)Amygdala c)Hippocampus d)Hypothalamus CorrectAnswer-DAns.is'd'i.e.,Hypothalamus
119.Correctorderofvelocity? a)Venacava>Aorta>Vein>Artery>Venule>Arteriole b)Aorta>Venacava>Artery>Vein>Arteriole>Venule c)Aorta>Artery>Venacava>Vein>Arteriole>Venule d)Venacava>Vein>Aorta>Artery>Venule>Arteriole CorrectAnswer-BAns.is`b'i.e.,Aorta>Venacava>Artery>Vein>Arteriole>Venul
120.Maximumwaterreabsorptioninthe Gastrointestinaltractoccursin? a)Stomach b)Jejunum c)Ileum d)Colon CorrectAnswer-BAns.is'b'i.e.,JejunumWaterabsorptionfromGITWaterandelectrolytesneednodigestionandareabsorbedassuch.Thereisapproximately9litersofwaterinput:Ingestedwater:2.0litres,Saliva:1.5litres,gastricjuice:2.5litres,bile0.5litre,pancreaticjuice:1.5litres,andsmallintestinesecretions1-0litre.Outofthese9litres,7.7litres(85%)isabsorbedinsmallintestineand1.0-1.5litres(5-10%)isabsorbedinlargeintestine(colon).Total8.8litresofwaterisabsorbedand0.2litreisexcretedinfeces.Insmallintestine,mostofthewaterisreabsorbedinthejejunum.
121.Thyroidglandisstimulatedbywhich hormoneduringpregnancy? a)Prolactin b)HCG c)Humanplacentallactogen d)ACTH CorrectAnswer-BAns.is'b'i.e.,HCGTheendocrinesystemundergoesnoteworthychangesduringpregnancy.Thepituitary,thyroidandparathyroidglandsappearenlarged.TheenlargementofthyroidglandoccursundertheinfluenceofhCGspituitarythyrotropin(TSH)andhumanchorionicthyrotropinfromplacenta.Thisresultsinanincreaseinthyroxinewhichstimulatesmetabolicactivityinmotherandfetus.Increasedparathyroidhormonestimulatesliberationofcalciumionfrommaternalbonesforfetaluse.IncreasedoutputofACTHfrompituitarystimulatessecretionof:- i. Glucocorticoids:Itmobilizesaminoacidsforproteinsynthesisin fetaltissues. ii. Aldosterone:Promotesfluidretentioninpregnancy.
122.FSHandLHbothareinhibitedby? a)Cortisol b)Aldosterone c)Estrogen d)Progesterone CorrectAnswer-CAns.is'c'i.e.,EstrogenConsistentwiththephenomenonofnegativefeedbackinwhichthesecretionofthetargethormoneinhibitsitstrophichormone,pregesteroneinhibitsLHandinhibininhibitsFSH.Estrogen,whosesecretionisstimulatedbybothLHandFSH,inhibitsbothLHandFSH.Progesteroneandestrogenactatbothhypothalamicandpituitarylevelswhileinhibinsecretedbygranulosacellsactsonlyonthepituitary.Undercertainconditions,estrogencausesstimulation(positivefeedback)ratherthaninhibitionofLH,e.g.,atovulation.
123.Gammaglutamatecarboxypeptidaseis linkedwithabsorptionof? a)Riboflavin b)Niacin c)Folicacid d)Pyridoxinel CorrectAnswer-CAns.is'c'i.e.,FolicacidFolicacidorpteroylglutamicacidisaparentcompoundforagroupofsubstancescalledfolates.Naturallyoccurringfolicacidtypicallyoccursaspteroylpolyglutamate,whichissimplefolicacidthathasbeenconjugatedbygammapeptidelinkagewithsixadditionalglutamylunits.Thesepteroylpolyglutamatesarehydrolysedtopteroylmonglutamatesintheprocessofintestinalabsorption.Thesmallintestinalmucosacontainsgammaglutamatecarboxypeptidase,ahydrolyticenzymeusuallyknownasfolateconjugase,withreleasesmonglutamicfolate,whichisrapidlyabsorbedfromtheuppersmallintestine.Thusgammaglutamatecarboxypeptidaseisinvolvedintheabsorptionoffolicacid.
124.Theoxygendissociationcurveof myoglobin&hemoglobinisdifferentdueto? a)Hbcanbindto2oxygenmolecules b)CooperativebindinginHb c)Myogloobinhaslittleoxygenaffinity d)Hemoglobinfollowsahyperboliccurve CorrectAnswer-BAns.is`b'i.e.,CooperativebindinginHbCooperativebindingisresponsibleforsigmoidshapeoftheoxygen-hemoglobindissociationcurve.Asmyoglobinismonomeric(consistsofonepolypeptidechainonly),itcanbindonlyonemoleculeofoxygenandforthesamereasonmyoglobincannotshowthephenomenonofcooperativebinding.Hence,theoxygen?myoglobindissociationcurveishyperbolaascomparedtosigmoidshapeofHb-O2curve.Hemoglobin-O2bindingEachmoleculeofhemoglobincancombinewithuptofourmoleculesofoxygen.Combinationwiththefirstmoleculealterstheconformationofthehemoglobinmoleculeinsuchawayastofacilitatecombinationwiththenextoxygenmolecule.Inlightofthis,ifwelookatthecurve,asthePO2startsrisingfrom0mmHgupwards,initiallyallhemoglobinmoleculesinbloodstartscombiningwiththeirfirstoxygenmolecule.Thisisthemostdifficultmoleculetocombinewith.HencesaturationrisesonlyslowlywithinitialriseinPO2.AsPO2risesfurther,hemoglobinmoleculescombinewiththeirsecond,thirdandfourthmolecules,whichareprogressivelyeasierto
combinewith.HencesaturationrisessteeplybetweenPO2of15mmHgand40mmHg.WhenPO2risesstillfurther,oxygenfindsmostofthehemoglobinmoleculescarryingfourmoleculesofoxygeneach.Sincenomoleculesofhemoglobincancarrymorethanfourmoleculesofoxygen,thereisnotmuchscopeformoreO2combiningwithhemoglobin.HencethecurvebecomesalmostflatagainbeyondthePO2of60mmHg.Thus,theprimaryreasonforthesigmoidshapeoftheoxygen-hemoglobindissociationcurveisthatoutofthefourmoleculesofoxygenthatcancombinewithahemoglobinmolecules,thefirstcombineswiththegreatestdifficultyandbindingofanoxygenmoleculesincreasesaffinitytonextO2molecule.Thisphenomenonistermedascooperativebindingorcooperativity,i.e.,amoleculeofO2bindstoahemoglobintetramermorereadilyifotherO2moleculesarealreadybound.MyoglobinO2bindingMyoglobinispresentinhigherconcentrationinred(slow)musclefibers.MyoglobinhasgreateraffinityforoxygenthanhemoglobinanditsP50isonly5mmHg(ascomparedtoPO2ofhemoglobinwhichisabout26mmHg).Therefore,myoglobin-oxygendissociationcurveisshiftedfartotheleftthanHb-O2dissociationcurve.IthasshapeofhyperbolaascomparedtosigmoidshapeofHb-O2curvebecauseitbinds1moleculeofO2permole(incomparisontoHbwhichbinds4moleculesofO2permole).TheroleofmyoglobinistobindO2atverylowPO2andreleasethematevenlowerPO2,forexampleinexercisingmuscleswherePO2closetozero.
125.Myosinandactinfilamentsarekeptin placeby a)Tropomyosin b)Troponin c)Actinin d)Titin CorrectAnswer-DAns.is'd'i.e.,TitinTheside-by-siderelationshipbetweenthemyosinandactinfilamentsisdifficulttomaintain.Thisisachievedbyalargenumberoffilamentousmoleculesofaproteincalledtitin.Titinmoleculesactasaframeworkthatholdsthemyosinandactinfilamentsinplacesothatthecontractilemachineryofthesarcomerewillwork.Importantmuscleproteins 1. Myosin:-Myosinistheproteinthatconstitutesthethickfilaments. Myosinofskeletalmuscleismyosin-ILMyosinparticipatesinthecontractilemechanismandalsoactsasanATPase. 2. Actin:-Actinisthemajorproteinofthinfilament.Itistheactinthat slidesovermyosinduringcontraction. 3. Tropomyosin:-Itistheotherproteinofthin.filament.Itcoversthe activesites(myosin-bindingsites)onactin.WhenCa+2concentrationofcytoplasm(sarcoplasm)israised,ituncoverstheactivesitesofactinandallowsthecontractionSo,the'cross-bridgecycling'isswitchedofforonbythetropomyosinmoleculewhichslidesontheactinmoleculetocoveroruncovertheactivesiteson
it.
126.Trueaboutcerebellarneuronal connections? a)Climbingfibresfrominferiorolivarynucleus b)Mossyfibresfrominferiorolivarynucleus c)ClimbingfibresareinhibitorytoPurkinjecells d)MossyfibresareinhibitorytoPurkinjecells CorrectAnswer-AAns.is'a'i.e.,ClimbingfibresfrominferiorolivarynucleusNeuronalcircuitincerebellumAfferentforcerebellumcomesthroughtwofibers:climbingfibersandMossyfibers.Climbingfiberswhichbringsinformationonlyfromtheinferiorolivarynucleiandestablishexcitatorysynapeswithpurkinjecells.Allotherafferentinputtothecerebellumisbroughtbytheothertypesoffibers,calledMossyfiberswhichestablishexcitatorysynapsewithgranulecellsinthegranularcelllayer.Theaxonofgranulecells,calledparallelfibers,stimulatethepurkinjecells.Thusmossyfibers,liketheclimbingfibers,alsoendupinstimulatingthepurkinjecells.Granulecellsaretheonlystimulatory(excitatory)cellsincerebellarcortex.Theparallelfibers(axonsofgranulecells)alsostimulatethreetypesofinterneurons:-Stellateandbasketcellsinthemolecularlayer,andGolgicellsinthegranularlayer.Stellateandbasketcellsinhibitpurkinjecells.Golgicells,alsoactivatedbycollateralfrommossyfibers(besidesparallelfibers),inhibittransmissionfrommossyfiberstogranulecells.Overall,climbingfiberinputsexertastrongexcitatoryeffectonasinglepurkinjecell,Whereasmossyfiberinputsexertaweak
excitatoryeffectonmanypurkinjecellsviathegranulecells.Aftercomplexinhibitingandexcitatoryinteractionsofvariousfibersandcellsinthecortex,theoutputofcerebellarcortex,isprojectedtodeepcerebellarnucleibyaxonsofpyramidalcells(onlyoutputcellsofcerebellarcortex).TheoutputofthePurkinjecellsisinhibitorytothedeepcerebellarnuclei.However,theoutputofdeepcerebellarnucleitothebrainstemandthalamusisalwaysexcitatorybecause,besideinhibitoryinputsofpurkinjecells,deepcerebellarnucleialsoreceiveexcitatoryinputsfromafferentmossyandclimbingfiberswhichusuallyaremoreprominent.
127.LifespanoffetalRBCis? a)SameasadultRBC b)1/4ofadultRBC c)1/2ofadultRBC d)2/3ofadultRBC CorrectAnswer-DAns.is'd'i.e.,2/3ofadultRBC"LifespanoffetalRBCisabout2/3'oftheadultRBC,i.e.about80days."
128.Baroreceptorare? a)Carotidbody b)Carotidsinus c)Aorticbody d)None CorrectAnswer-BAns.is'b'i.e.,CarotidsinusBaroreceptorsaremechanoreceptorsthatarelocatedintheadventiaofcarotidarteryandaorta,atspecializedlocationscalledsinuses.1)Carotidsinusisalittlebulgeattherootofinternalcarotidartery,locatedjustabovethebifurcationofthecommoncarotidartery.Itisinnervatedbythesinusnerve,abranchofglossopharyngeal(IXcranial)nerve.2)Aorticarch(aorticsinus)alsocontainsmechenoreceptors(stretchreceptors)whicharesimilartocarotidsinusreceptors.However,theirafferentnervefiberstravelintheaorticnerve,abranchofVagus(Xcranial)nerve.Thesinusnerve(fromcarotidsinus)andaorticnerve/vagalfibers(fromaorticsinus)aretogethercalled`Sinoaorticnerves'.They,together,arealsoreferedtoas'Buffernerves'becausetheyaretheafferentsofcardiovascularreflexesthatbufferabruptchangesinbloodpressure.
129.Insulinsecretionisnormallystimulated by? a)GLP-1 b)GLP-2 c)VIP d)-adrenergicreceptors CorrectAnswer-AAns.is'a'i.e.,GLP-1Recently,attentionhasbeenfocusedonglucagon-likepolypeptide1(7-36)(GLP-1[7-36])asanadditionalgutfactorforinsulinsecretionandGLP-1(7-36)ismorepotentinsulinotropichormone.RegulationofinsulinsecretionFactorsaffectinginsulinsecretionare:-i)Simulatinginsulinsecretion:-Glucose;Mannose;Aminoacids(arginine,leucine);Intestinalhormones(GIP.Gastrin,Secretin,CCK,GLP-1);-ketoacids;Parasympetheticstimulation(acetylcholine);cAMP;-adrenergicstimulation;theophylline;Sulfonylureas;andcertainendocrinehormoneslikegrowthhormone,Glucagonandglucocorticoids.ii)Inhibitinginsulinsecretion:-Somatostatin;2-deoxyglucose;mannoheptulose;a-adrenergicstimulation,P-adrenergicinhibitors;galanin;Diazoxide;Thiazidediuretics;K+depletion;Phenytoin;Alloxan;microtubuleinhibitors;andinsulinitself.
130.Insulinmediatedglucosetransportis seenin? a)Adiposetissue b)Brain c)RBC d)Kidney CorrectAnswer-AAns.is'a'i.e.,AdiposetissueInsulinstimulatestheuptakeofglucosebymyocytes(skeletalmuscle,cardiacmuscles),adipocytes(adiposetissue)andhepatocytes.Tissuesthatdonotdependoninsulinforglucoseuptakeincludebrain,erythrocytes(RBC),theepithelialcellsofkidney&intestine,Liver,andCornea&lensofeye.Themechanismthroughwhichinsulinincreasesglucoseuptakeisdifferentindifferenttissues.Inthemuscleandadiposetissues,insulinincreasefacilitateddiffusionbyincreasingglucosetransporter(GLUT4)onthecellmembrane.Intheliver,insulinstimulatesglucoseentryintohepatocytesindirectlybyinductionofglucokinasesothattheglucoseenteringthelivercellsispromptlyconvertedtoglucose-6-phosphate(glucosetrapping).Thiskeepstheintracellularglucoseconcentrationlowandfavoursentryofglucoseintotheliver.Thus,thoughtheliverdonotdependoninsulinforglucoseuptake,insulinstimulatesglucoseentryintohepatocytes.Thatmeansglucoseenterycanoccurinliverwithouttheactionofinsulin,butthisisfacilitatedbyinsulin.Ontheotherhand,myocytes(skeletalandcardiacmuslces)andadipocytes(adiposetissue)aredependentoninsulinforglucoseuptake.
131.IncreasedBMRisassociatedwith? a)Increasedbodyfatstore b)Increasedglycognenesis c)Increasedglycolysis d)Increasedlipogenesis CorrectAnswer-CAns.is'c'i.e.,IncreasedglycolysisIncreasedBMRisassociatedwithhypermetabolicstatewhichischaracterizedby:?A)Carbohydratemetablismi)Glycolysisii)Gluconeogenesisiii)Glycogenesisiv)GlycogenolysisB)Lipidmetablismi)Lipogenesisii)Lipolysisiii)CholesterolSynthesisiv)TriacylglycerolSynthesisv)Lipoproteindegradationvi)KetogenesisC)Proteinmetablismi)Increasedproteindegradationii)Decreasedproteinbiosynthesis
132.Post-tetanicpotentiationisdueto- a)Hyperpolarizationofmusclefibres b)RapidK+efflux c)IncreasedavailabilityofCa++ d)RapidNa+influx CorrectAnswer-CAns.is'c'i.e.,IncreasedavailabilityofCa++"RepetitivestimulationenhancesforcedevelopmentduetoriseinintracellularCa++,aphenomenoncalledposttetanicpotentiation.Itisduetoincreasedphosphorylationofmyosinelightchainwithincreasednumberofcrossbridges."
133.Whichofthefollowinghassmall representationinsomatosensoryareaofcerebralcortex? a)Lips b)Thumb/fingers c)Tongue d)Trunk CorrectAnswer-DAns.is'd'i.e.,TrunkAdistincttopographicrepresentionofthebodycanbedemonstratedinsomatosensoryarea-I.Eachsideofthecortexreceivessensoryinformationfromtheoppositesideofthebodyonly(contralateralrepresentation).Thebodyisrepresentedupsidedown(vertical)inthepostcentralgyms,i.e.thefaceisrepresentedatthefootofthegyruswhereasthelegsandfeetarerepresentedatthetopextendingonthemedialsurface.Somepartsofbodylikeface(especiallylips,tongue)andfingershaveaproportionatelylargerepresentationthantheotherareaslikethetrunk.Thecorticalrepresentationofthepartofthebodyisproportionatetoitsinnervationdensity(numberofsensoryreceptors)ratherthanitssize.
134.FactorXis? a)Hagemanfactor b)Stuart-Prowerfactor c)Christmasfactor d)Tissuefactor CorrectAnswer-BAns.is'B'i.e.,Stuart-Prowerfactor
135.Restingmembranepotentialincardiac muscle? a)-70mV b)+70mV c)-90mV d)+90mV CorrectAnswer-CAns.is'c'i.e.,-90mVNormalRMPinmyocardialfibersisabout-90mV.
136.EffectofGLP-1? a)Increasedaldosteronesecretionbyadrenal b)IncreasedPTHsecretion c)Increasedinsulinsecretionfrombeta-cellsofpancreas d)IncreasedtestosteronesecretionfromLeydigcells CorrectAnswer-CAns.is'c'i.e.,Increasedinsulinsecretionfrombeta-cellsofpancreas
137.Noradrenalineismajorneurotransmitter in? a)Postganglionicparasympatheticfibres b)Postganglionicsympatheticfibresexceptinsweatglands c)Autonomicganglia d)Preganglionicautonomicfibres CorrectAnswer-BAns.is'b'i.e.,PostganglionicsympatheticfibresexceptinsweatglandsNeurotransmitterinallpreganglionicautonomicnerves(bothsympatheticandparasympathetic)isacetylcholine(ACH)Neurotransmitterinallganglia(bothsympatheticandparasympathetic)isacetylcholine.Neurotransmitterinpostganglionicparasympatheticfibresisacetylcholine.Inposganglionicsympatheticfibres,themajorneurotransmitterisnoradrenaline(NA)exceptinrenalandmesentricvasculaturewhereitisdopamine,insweatglands,somebloodvesselswhereitisacetylcholineandinadrenalmedullawhereitisadrenaline.Mostofthevisceralorgansaresuppliedbybothsympatheticandparasympatheticsystemexcept; 1. Bloodvessels,spleen,sweatglandsandhairfolliclesreceiveonly sympatheticinnervation. 2. Ciliarymusclegastricandpancreaticglandsreceiveonly parasympatheticinnervation.Ingeneralsympatheticandparasympatheticsystemsareantagonisticexcept:Refractoryperiodofatrialfibresisdecreasedbyboth.
Atalmostallorgansexceptheart,cholinergicsystemhasexcitatoryactivityandadrenergicsystemhasrelaxingpropertiesSympatheticsystemstimulates(Tachycardia,Positiveinotropic)andparasympatheticsystemdepresses(Bradycardia,Negativeinotropic)theheart.
138.Gammaglobulinaresynthesizedin? a)Liver b)Spleen c)Kidney d)Plasmacells CorrectAnswer-DAns.is'd'i.e.,PlasmacellsLiversynthesizesmostoftheproteinsofbodyexceptimmunoglobulins(gammaglobulins),whicharesynthesizedbyplasmacells.
139.Normalcerebralbloodflowinml/min? a)55 b)150 c)750 d)1000 CorrectAnswer-CAns.is'c'i.e.,750Thecerebralbloodflow(CBF)isabout750ml/min(15%oftotalcardiacoutput),or54m1/100gmbraintissueperminute
140.Roleofgrowthhormonein spermatogenesis? a)Latedivisionofspermatocytes b)Earlydivisionofspermatogonia c)FormationofAcrosomes d)StimulationofsertoliandLeydigcells CorrectAnswer-BAns.is`b'i.e.,EarlydivisionofspermatogoniaGrowthhormonespecificallypromotesearlydivisionsofspermatogoniathemselves.IntheabsenceofGH,spermatogenesisisseverelydeficientorabsent.Growthhormoneisalsoessentialforgeneralmetabolicprocessintestis.HormonesinvolvedinspermatogenesisSpermatogenesisisinfluencedbymanyhormones.HormonesrequiredforspermatogenesisareFSH,LH,testosterone,estrogen,growthhormonesinhibinandactivin.FSHisresponsibleforinitiationofspermatogenesis.Itbindswithsertolicellsandspermatogoniaandinducestheproliferationofspermatogonia.Itstimulatescertolicellstosecreteendrogenbindingprotein,inhibin,mullerianinhibingsubstanceandestrogen.LHstimulatesleydigcellstosecretetestosterone.Testosteroneistheprincipleshormonewhichdirectlystimulatesspermatogenesis.Itisresponsibleforthesequenceofremainingstagesofspermatogenesis(afterinitiatinbyFSH).Itisalsoresponsibleformaintenanceofspermatogenesis.Estrogenisformedfromtestosterone(byaromatase)insertolicells.Itisessentialforspermeogenesis(laststepofspermatogenesis,i.e.formationofspermatozoafromspermatids).
formationofspermatozoafromspermatids).Growthhormoneisessentialypromotesearlydivisionofspermatogonia.InhibinplaysanimportantroleinregulationofspermatogenesisbyfeedbackinhibitionofFSHsecretion.ActivinstimulatesFSHsecretionandstimulatesspermatogenesis.
141.Growthhormonehasitseffectongrowth through? a)Directly b)IG1-1 c)Thyroxine d)Intranuclearreceptors CorrectAnswer-BAns.is'b'i.e.,IGI-1GHhastwomajorfunctions:-i)Growthofskeletalsystem:-Thegrowthismediatedbysomatomedins(IGF).Increaseddepositionofcartilage(includingchondroitinsulfate)andbonewithincreasedproliferationofchondrocytesandosteocytes.ii)Metaboliceffects:-MostofthemetaboliceffectsareduetodirectactionofGH.Theseincludegluconeogenesis,decreasedperipheralutilizationofglucose(decreaseduptake),lipolysisandanaboliceffectonproteins.
142.Growthhormonedoesnotcause? a)Gigantism b)Acromegaly c)Diabetesmellitus d)Hypothyroidism CorrectAnswer-DAns.is'd'i.e.,HypothyroidismPhysiologicaleffectsofGrowthhormoneGrowthhormonehastwomajoraction,i.e.,(1)Stimulationofskeletalgrowth,and(2)Regulationofmetabolism.3)StimulationofskeletalgrowthTheeffectofGHonskeletalgrowthismediatedbysomatomedins(Insulin-likegrowthfactors:IGF).Theyaresynthesizedmainlyintheliver.Thegrowthpromotingactionofsomatomedinsishelpedbytheirinsulinlikeactions.GH,throughsomatomedin(IGF-1),stimulatesproliferationofchondrocytesandosteocytesresultinginincreaseddepositionofchondroitinsulfateincatilageandincreasedossificationofthenewlyformedcartilage.GHdeficiencyinearlylifecausesdwarfism(smallheight).GHexcessinearlylifeleadstogigantism,whereasgrowthhormoneexcessinadulthoodresultsinacromegaly.2)RegulationofmetabolismProteinmetabolism:-GHhaspredominantlyanaboliceffectsonskeletalandcardiacmusclewhereitpromotesaminoacidtransportintocellsandincreaseproteinsynthesis.Carbohydrateandfatmetabolism:-TheeffectsofGHoncarbohydrateandfatmetabolismarecomplicatedbythefactthatGHhasanti-insulineffects,whereassomatomedinsitproduceshave
insulinlikeeffects:-i)Anti-insulineffectsduetodirecteffectofGHincludedecreasedperipheralutilizationofglucose,increasedgluconeogenesis,hyperglycemia,andlipolysis.Duetoitsanti-insulineffectsGHexcesscancauseinsulinresistantdiabetesmellitus.ii)Insulinlikeeffectsduetosomatomedins(IGF)includeantilipolyticactivity,andotherinsulinlikeeffects.
143.Migratingmotorcomplexisduetowhich GIhormone? a)Gastrin b)Motilin c)CCK d)VIP CorrectAnswer-BAns.is'b'i.e.,MotilinMigratorymotorcomplex(MMC)Thegastricantrumshowsburstsofpropulsive(peristalitic)muscularactivityevery90minutes.Theactivityisconductedalongtheentirelengthofthesmallintestine,fromstomachtodistalileum,atarateofabout5cmperminute.Assoonastheactivityreachestheterminalileum,anewwavebeginsinthestomach.ThepurposeofMMCistoclearthestomachandsmallintestineofluminalcontentsinpreparationforthenextmeal.TheMMCsareinitiatedbymotilin.
144.Sensationswhichareappreciatedin thalamus a)Proprioception b)Pain&temperature c)Tactilesensations d)Pressure CorrectAnswer-BAns.is'b'i.e.,Pain&temperaturePainandtemperatureareprimarilyappreciatedbythethalamus.Forotherformsofsensation,thethalamusisunabletoanalyzethedetailsofsensations.Fiberscarryingtactileandproprioceptiveinformationascendthroughthethalamocorticalpathwaytoarea3ofprimarysomaticsensorycortexthroughthethalamicradiation.Therefore,ifthesomatosensorycortexisremoved,tactilesensationsandproprioceptionsarelost,butpainandtemperaturesensationspersist.
145.NOactsonplateletsthrough? a)cAMP b)Adenosine c)cGMP d)TX-A2 CorrectAnswer-CAns.is'c'i.e.,cGMP
146.Mitralandperiglomerularcellsareseen in? a)Medulla b)Olfactorybulb c)Primaryvisualcortex d)Geniculatebody CorrectAnswer-BAns.is'b'i.e.,OlfactorybulbThesensoryreceptorsforolfaction(smell)arelocatedintheolfactorymucousmembrane.Inhuman,theolfactorymucousmembrane(olfactoryneuroepithelium)locatedintheroofofthenasalcavityneartheseptum.Becauseofitslocationhighinthenasalcavity,theolfactorymucosaisnotdirectlyexposedtotheflowofinspiredairenteringthenose.Theolfactorymucosacontainsolfactoryreceptors.Theolfactoryreceptorsareuniqueinthatthereceptorcellitselfisaneuron.Theolfactoryreceptorcellhasciliaprojectinginthenasalmucosawhichactasreceptorforolfaction(Thesearedendritesofneuron/receptorcells).Theaxonsofolfactoryneuron(olfactoryreceptorcells)formolfactorynervewhichpassesthroughcribriformplateandterminatesintheolfactorybulb.Inolfactorybulbaxonsofolfactorynervesynapsewithdendridesofmitralcellstoformtheolfactoryglomeruli.Mitralcellsaretheprincipaloutputneuronsofolfactorybulbandtheiraxonsformtheolfactorytract.Theolfactorybulbalsocontainsperiglomerularcells,whichareinhibitoryneuronsandgranulecellswhichhavenosynapseandmakereciprocalsynapseswithmitalandtuftedcells.Likethetastefibers,olfactorytractalsoprojectstotheprimitiveparts
ofthebrainaswellastheneocortex.Theprojectionstotheprimitivepartsareprincipallytothepyriformarea(olfactorycortex),amygdalaandentorhinalcortex,whichinturnprojectstothehippocampus.Thepathwaytotheneocortexinvolvesarelayintheolfactorytubercle,andtheninthethalamus,theoutputofwhichprojectstotheorbitofrontalcortex.
147.DerivativeofPOMC a)Norepinephrine b)Dopamine c)ACTH d)Acetylcholine CorrectAnswer-CPro-opiomelanocortin(POMC)comprises285aminoacidresidues(MW31000)andservesasaprecursorofmanyproteins/polypeptide.DerivativesofPOMCare:-i)Pituitaryhormones:ACTH,MSHii)-lipotropichormone(-LPH)iii)-lipotropichormone(-LPH)iv)-endorphinv)CLIP(corticotropin-likeintermediatelobepeptide).
148.Preaccelerinis? a)EaterII b)FacterV c)FacterVII d)FacterX CorrectAnswer-CAns.is'c'i.e.,FacterVII
149.Whichofthefollowingisnotan intermediatefilament? a)Keratin b)Desmin c)Tubulin d)Lamin CorrectAnswer-CAns.is`c'i.e.,Tubulin
150.Antimullerianhormoneissecretedby? a)Granulosacells b)Lyedigcells c)Sertolicells d)None CorrectAnswer-CAns.is'c'i.e.,SertolicellsAntimullerianhormoneorMullerianinhibitingsubstanceissecretedbysertolicells.
151.Hepcidininhibits? a)Absorptionofcobalamine b)Transferofironintoenterocytes c)Folicacidsynthesis d)Respiratoryoxidase CorrectAnswer-BAns.is'b'i.e.,TransferofironintoenterocytesHepcidinisanironmetabolismregulatoryhormonethatinhibitsironabsorption(transferofironintoenterocytes).Ascorbicacid(vitaminC)formssolublecomplexeswithironandreducesironfromtheferrictotheferrousstate,therebyenhancingironabsorption.Tannins,presentintea,forminsolublecomplexeswithironandloweritsabsorption.
152.Strokevolumeisincreasedby? a)Increasedend-diastolicandend-systolicvolumes b)Decreasedend-diastolicandend-systolicvolumes c)Increasedend-diastolicvolumeanddecreasedend-systolic volume d)Decrasedend-diastolicvolumeandincreasedend-systolic volume CorrectAnswer-CAns.is'c'i.e.,Increasedend-diastolicvolumeanddecreasedend-systolicvolumeThestrokevolumeistheamountofbloodpumpedoutbyleftventricleineachstroke.Strokevolumeisgivenbythedifferencebetweenend-diastolicventricularvolume(thevolumeofbloodintheleftventricleattheendofdiastole;normal120inl)andend-systolicventricularvolume(thevolumeofbloodattheendofsystole;normal50ml).Strokevolume(70ml)=End-diastolicventricularvolume(120ml)-End-systolicventricularvolume(50ml)
153.Effectofinfusionofhypotonicsaline? a)IncreasedICFonly b)IncreasedECFonly c)IncreasedinbothICFandECF d)IncreasedICFanddecreasedECF CorrectAnswer-CAns.is'c'i.e.,IncreasedinbothICFandECFAfterinfusionofhyptonicsalinecausesadeclineinplasmaosmolalityandashiftofwaterintointerstialspace(aswatermovesfromhigherosmolaritytolowerosmolarity),causingdecreaseinICFosmolality.ThisresultsinshiftofwaterfromECFtoICF.Finally,bothECFandICFcompartmentsareincreased(duetoincreaseswater)andosmolalityofbothcompartmentaredecreased.
154.Smoothmusclephysiologydifferent fromskeletalmuscle a)K+requiresforcontraction b)Ca2+requiredforcontraction c)Troponinisabsent d)Myosinisrequiredforcontraction CorrectAnswer-CAns.is'c'i.e.,Troponinisabsent*Troponinisabsentinsmoothmusclebutrequiredinskeletalmusclesforcontraction.*Ca+andMyosinarerequiredbybothsmoothmusclesandskeletalmuscles.*K+hasnodirectroleinthecontractionofsmoothmuscleandskeletalmuscle.Smoothmusclecontraction*Insmoothmuscle,thereisnotroponin.Thereforecalciuminitiatescontractionthroughamechanismdifferentfromthatemployedbyskeletalmuscle.Smoothmusclecontainsacalcium-bindingproteincalledcalmodulin.Anincreaseincytoplasmic(sarcoplasmic)calciumleadstoitsbindingtocalmodulin.Thecalcium-calmodulincomplexactivatesmyosinkinase,alsocalledmyosinlightchainkinase(MLCK).MLCKisaphosphorylasewhichphosphorylatesalightchainbelongingtomyosinchain,oftencalledcross-bridgephosphorylation.Thephosphorylatedmyosinheadinteractswithactin,i.e.,cross-bridgingofmyosinwithactin.Thecross-bridgingleadstocontraction.*Thereversalofcontractileresponsedependsonareductionin
sarcoplasmiccalciumbycalciumpumpsinthesarcoplasmicreticulummembraneandsarcolemmawhichpumpcalciumintothesarcoplasmicreticulumandextracellularfluidrespectively.Reductionincytoplasmic(sarcoplasmic)calciumlevelactivatesanenzymemyosinphosphatase.Myosinphosphatasedephosphorylatesthemyosinhead,therebyterminatingtheactin-myosininteractionandproducesrelaxation.So,calciuminfluxhastwofunctionsinsmoothmuscles:-*Generationofactionpotential*Essentialforcontractioninitiation(Excitationcontractioncoupling)-Itisinterestingtoknowthatalthoughdephosphorylationofmyosinheadisnecessaryforrelaxation,thedephosphorylationofmyosindoesnotnecessarilyleadtotherelaxationofthesmoothmuscle.Thisisduetothelatchingeffect,i.e.,myosinbridgesholdontotheactinfilamentlikealatch.Duetothissmoothmusclecontracts,anditcanmaintainitscontractionforaprolongedperiod(sustainedcontraction)foralongperiodwithminimalexpenditureofenergyCharacteristicfeatureofsmoothmuscle.-Aswithskeletal,muscleATPisrequiredwhichishydrolyzedbymyosinheadwhichhasATPaseactivity(Inasimilarwayasinskeletalmuscle).
155.Normalrespiratorycomplianceis? a)200ml/cmwater b)50ml/cmwater c)100ml/cmwater d)150ml/cmwater CorrectAnswer-AAns.is'a'i.e.,200ml/cmwaterThelungsandthoraciccagearebothelasticstructures.Hencetheydisplayaconstantrelationshipbetweendistendingpressureandchangeinvolume.Thechangeinvolumeperunitchangeinpressureiscalled"compliance".Thetotalcomplianceofbothlungstogetherinthenormaladulthumanbeingisabout0.2L/cmwater.Thatis,everytimethetranspulmonarypressureincreasesby1centimeterofwater,thelungvolumewillexpand0.2L(200ml).Complianceisameasureofdistensibility.
156.Cushingreflexisassociatedwithall except? a)Hypotension b)Increasedintracranialpressure c)Bradycardia d)Tachyponea CorrectAnswer-AAns.is'a'i.e.,HypotensionAriseinintracranialpressurecausesimpairedbloodsupplytoVMC(RVLM)neuronsandthelocalhypoxiaandhypercapniaincreasetheirdischargetothesystemicresistancevessels,i.e.,cushingreflex.TheresultantriseinBPtendstorestorecerebralbloodflowandoveraconsiderablerange,theBPriseisproportionaltotheincreaseinintracranialpressure.TheincreaseinBPcausesreflexbradycardiathrougharterialbaroreceptors.Thatiswhybradycardiaratherthantachycardiaischaracteristicallyseeninpatientswithincrease(ICP).Cushingreflexconsistsofhypertension(increasedBP),bradycardiaandtachyponea.
157.Whichofthefollowingtechniqueisused tostudycurrentflowacrossasingleionchannel? a)Patchclamp b)Voltageclamp c)lontophoresis d)Galvanometry CorrectAnswer-AAns.a.Patch-clampPatch-clampisatechniquetorecordioncurrentflowthroughasingleproteinchannel.Thepatch-clamptechniqueisalaboratorytechniqueinelectrophysiology,thatallowsthestudyofsingleormultipleionschannelsincells.Thetechniquecanbeappliedtoawidevarietyofcellsbutisespeciallyusefulinthestudyofexcitablecellssuchasneurons,cardiomyocytes,musclefibers,andpancreaticbetacells.Itcanalsobeappliedtothestudyofbacterialionchannelsespeciallypreparedgiantspheroplasts.Inthepatch-clampexperiment,asmallpipetteiscarefullymaneuveredtosealoffaportionofacellmembrane.Thepipettehasanelectrodebathedinanappropriatesolutionthatallowsfortherecordingofelectricalchangesthroughanyporeinthemembrane.
158.Poiseuille'sequationstatesthat a)Bloodflowisdirectlyproportionto2ndpowerofradius b)Bloodflowisdirectlyproportionto4thpowerofradius c)Bloodflowisinverselyproportionto2ndpowerofradius d)Bloodflowisinverselyproportionto4thpowerofradius CorrectAnswer-BBloodflowisdirectlyproportionedto4thpowerofradius.POISEUILLE'SLAW:*Alsoreferredas"Hagen-Poiseille'sLaw".*Poiseuille'sequationstates,-Q=P1-P2*{(r4)/(8L)}-Q-Flowrate-(P1-P2)-Pressuredifferenceacrossvessel(providedP1>P2).--Bloodviscosity.-r-Radius.-L-Tubelength.*Ifparametervaluesremainsconstant,-Bloodflowisdirectlyproportionalto4thpowerofradius.*ResistanceofvesseltobloodflowcanbecalculatedbycombiningOhm'slawwithPoiseuille'sequation.-BysubstitutingvaluesofQfromPoiseuille'slawinOhm'slaw.*Implying,resistanceismainlyaffectedby,-Bloodvesselradius,-Vasodilatation/vasoconstriction.*Thusultimately,ifparametervaluesremainconstant,_Resistancetobloodflowisinverselyproportionalto4thpowerofradius.
159.Trueaboutcalciumreabsorptioninthekidney? a)MostofthecalciumreabsorptionoccursinDCT b)MajorregulatingfactorisParathormone c)Parathormonedecreasescalciumreabsorption d)Increasedplasmaphosphatedecreasescalciumreabsorption CorrectAnswer-BMajorregulatingfactorisparathormone.Theprimarycontrollerofrenaltubularreabsorptionisparathormone.ItincreasescalciumreabsorptioninLoopofHenle(thickascendinglimb)anddistaltubules.Mostofthecalcium(6590)isreabsorbedinPCT.Increasedplasmaphosphateincreasescalciumreabsorption.
160.Whichcarrierpumpistransportingsolutesinthick ascendinglimbofHenleloop? a)CarrierpumpNa-K-2Cltransporter. b)NaCl-cotransporter c)Na2+-H+exchanger d)Na2+-K+exchanger CorrectAnswer-ACarrierpumpNa-K-2Cltransporter.REABSORPTIONINTHICKASCENDINGLIMB:Sodium,Potassium&Chloridereabsorption:By"Secondaryactivetransport"-ThroughNa2+-K+-2Cl--carriertransporter.TransportsoneNa2+,oneK+,&twoCl-.Activesodiumabsorptionoccurs.30%filteredNa2+reabsorbed.
161.Whatisthepartialpressureforoxygenintheinspired air? a)116mmHg b)158mmHg c)100mmHg d)0.3mmHg CorrectAnswer-BPartialpressureofO2ininspiredair(PiO2)-158mmHgGaseousconcentration&itspartialpressureinalveoli:1.Oxygen:Concentration&partialpressurecontrolledby,*RateofabsorptionofO2intoblood*RateofentryofnewO2intolungsbyventilatoryprocess.Values:*PartialpressureofO2ininspiredair(PiO2)-158mmHg*PartialpressureofO2inalveolarair(PAO2)-100mmHg-Calculatedby"Alveolargasequation".*PartialpressureofO2inexpiredair(PEO2)-116mmHg2.Carbon-di-oxide:*PartialpressureofCO2ininspiredair(PiCO2)-0.3mmHg*PartialpressureofCO2inalveolarblood(PACO2)-40mmHg*PartialpressureofCO2inexpiredair(PECO2)-32mmHg
162.Whatarethecellularcontentsofcerebellarcortex? a)Corticalcells b)Glomuscells c)Principlecells d)Intercalatedcells CorrectAnswer-AAns.ACorticalcells.CELLSINCEREBRALCORTEX:Corticalcells:MajorityarepyramidalcellsPyramidalcells-"Sinequanon"forcerebralcortexAxonsofpyramidalcellsleavethecortexFormsdescendingtract(e.g.Corticospinal,Corticobulbaretc).
163.Whichcellsarereferredas"Pacemakercells"with relationto'BER'? a)SAnode b)AVnode c)InterstitialcellsofCajal. d)Pyramidalcells CorrectAnswer-CInterstitialcellsofCajalBasicElectricalRhythm(BER):Smoothmusclecellsofthegastrointestinaltracthavespontaneousrhythmicfluctuationsinmembranepotentialbetweenabout-65and-45mV.BERinitiatedbyPacemakercellscalled"InterstitialcellsofCajal".Pacemakercells-InterstitialcellsofCajal.Stellatemesenchymalcellswithsmoothmuscle-likefeatures.Location:Areabsentinesophagus&proximalstomach.Indistalstomach&smallintestine-Locatedinoutercircularmusclelayernearmyentericplexus.Incolon-Locatedatthesubmucosalborderofcircularmusclelayer.Frequency:InStomach&smallintestine-Pacemakerfrequencyisindescendinggradient.Pacemakerwiththehighestfrequencyusuallydominates(Eg.,InHeart).
164.Testosteronesecretedby, a)Leydig'scells. b)Somatotropiccells. c)Acidophiliccells. d)Gonadotropiccells CorrectAnswer-AAns:A.Leydig'scells.Thehypothalamussendsasignaltopituitaryglandtoreleasegonadotrophicsubstances(folliclestimulatinghormoneandluteinizinghormone).Luteinizinghormone(LH)stimulatestestosteroneproduction.Testosteroneisproducedbygonads(byLeydigcellsintestesinmen&byovariesinwomen).
165.Vasopressinactsthroughwhich channelsincollectingduct? a)Aquaporin1 b)Aquaporin2 c)GLUT? d)GLUT?4 CorrectAnswer-BAns:B.Aquaporin2Principalcellsofcollectingductcontainaregulatedsystemofwaterchannelsantidiuretichormone(ADH,alsocalledargininevasopressin,AVP).ADHcontrolspermeabilityofthesecellstowaterbyregulatinginsertionofpre-formedwaterchannels(aquaporin-2,AQP2)intoapicalmembrane.
166.Trueaboutdecorticaterigidity? a)Removalofcerebralcortexandbasalganglia b)Flexionoflowerlimbs&extensionofupperlimbs c)Rigidityislesspronouncedthandecerebraterigidity d)Noneoftheabove CorrectAnswer-CAns:C.Rigidityislesspronouncedthandecerebraterigidity.Decorticaterigidity:Madebyremovingwholecerebralcortexbutleavingbasalgangliaintact.Characterizedbyflexionofupperextrimitiesatelbow&extensionoflowerextrimities.Flexionduetorubrospinaltractexcitationofflexorsinupperextremities&hyperextensionoflowerextermity.Decorticateanimaldoesnothaveintensehypertoniaasdecerebrateanimal.Duetointactbasalgangliaindecorticateanimal.
167.Bainbridgerefluxcauses? a)Bradycardia b)Increasedcardiacoutput c)Decreasedvenousreturn d)Increasedheartrate CorrectAnswer-DAns:D.Increasesheartrate.BainbridgeReflex:Positivefeedbackmechanismwithcompensatoryincreaseinheartrate?Duetoriseinrightatrialpressure.Commonlyreferredtoas"atrialreflex".Resultingfromincreasedbloodpressureorincreaseddistensionoflargesystemicveins&rightupperchamberofheart.
168.Golgitendonorganresponsiblefor? a)Tension b)Length c)Pressure d)Proprioception CorrectAnswer-AAns:A.Tension.Differencebetweenfunctionsofmusclespindle&golgitendonorgan:Musclespindle:Actsas"Musclelengthdetectors".Alsodetectsrateofchangeinmusclelength.Golgitendonorgan:Actsas"Muscletensiondetectors".Alsodetectsrateofchangeinmuscletension.Becauseoflocationofmusclespindle&golgitendonorgan.Musclespindleareparalleltomusclefibers(extrafusalfibers).Golgitendonorganinseriestomusclefibers(extrafusalfibers).Yet,Bothareactivatedbymusclestretch.
169.Hormonepredominatelysecretedafter 14dayonendometriumis? a)Progesterone b)Estrogen c)LH d)FSH CorrectAnswer-AAns:A.Progesterone.Eventsofovariancycle:Bleedingcontinuesforabout4days.By5thday,ovarianfollicleissufficientlydeveloped.Secretesconsiderablequantitiesofestrogen.Duringpre-ovulatoryphase:Estrogeninfluencesendometrialproliferativechanges.Hence,"Preovulatoryphaseofuterinecycle"alsoreferred"Proliferativephase".Duringpost-ovulatoryphase:Endometriumenterssecretoryphase.Hence,"Postovulatoryphaseofuterinecycle"alsoreferred"Secretoryphase".Duetocombinedactionofestrogen&progesterone.Progesterone:Moreimportant&responsibleforsecretorychanges.Peakson21stday.Endofsecretoryphase:Estrogen-primedendometrium.Degenerationofcorpusluteumdeclinesestrogen&progesteronelevels.
Resultsinwithdrawalbleeding?Menstruation.
170.Peripheralchemoreceptorsrespondto hypoxiausingwhichchannel? a)Calciumchannel b)Sodiumchannel c)Potassiumchannel d)Chloridechannel CorrectAnswer-CAns:C.Potassiumchannel.Carotidbodiesarecomposedofglomuscells(alsocalledtypeI),whichareofneuronalphenotypeandcontainavarietyofneurotransmitters.Glomuscellsareinfunctionalcontactwiththeafferentnerveendings.Glomuscellsareinitialsite(s)ofsensorytransduction.Hypoxiareleasestransmitter(s)fromglomuscells,whichinturnbydepolarizingthesensorynerveendingleadstoanincreaseinsensorydischarge.OnehypothesisassumesthataK+-channelproteinisanO2sensorandthathypoxiadepolarizesglomuscellsbyinhibitingtheK+channel,leadingtoanincreaseincytosolicCa2+,resultingintransmitter(s)release.
171.Withincreaseinagewhichofthe followingistrueforlungs? a)Pulmonarycomplianceincreases b)Residualvolumedecreases c)Mucocillaryclearanceincreases d)Fibrousofinterstitiumdreaseses CorrectAnswer-AAns:A.PulmonarycomplianceincreasesAnatomicalandphysiologicalchangesofrespiratorysystemwithaging:Anatomical:Airspacesize:IncreasedCompliance:Chestwallcompliance:DecreasedLungcompliance:IncreasedtounchangedTotalrespiratorysystemcompliance:DecreasedMusclestrength:Maximalinspiratorypressure(MIP):DecreasedTransdiaphragmaticpressure(Pdi):DecreasedMaximumvoluntaryventilation(MVV):DecreasedLungfunction:FEV1:DecreasedFVC:DecreasedTLC:UnchangedVitalcapacity:DecreasedFunctionalresidualcapacity:IncreasedResidualvolume:IncreasedDLCO/VA:Decreased
Exercisecapacity:VO2max:DecreasedDeadspaceventilation:IncreasedImmunology:Bronchialfluid:Neutrophils%:IncreasedRatioofCD4+/CD8+cells:IncreasedEpithelialliningfluidantioxidants:Decreased.
172.Functionalresidualvolumeis? a)Afternormalinspiration b)Afternormalexpiration c)Afterforcefulexpiration d)Afterforcefulinspiration CorrectAnswer-AAns:A.AfternormalinspirationFunctionalResidualCapacity(FRC)isthevolumeofairpresentinthelungsattheendofpassiveexpiration.
173.Polyuriais- a)70ml/kg b)60ml/kg c)50ml/kg d)40ml/kg CorrectAnswer-CAns:C.50ml/kgConsideredpolyuricifurineproductionisgreaterthan50ml/kg/day.
174.Tubuloglomerularfeedbackcontrolis usefulforwhichoneofthefollowing? a)GFR b)Plasmasodium c)Plasmavolume d)Determiningtubularsecretion CorrectAnswer-AAns:A.GFR.Tubuloglomerularfeedback?Twocomponents:*Afferentarteriolefeedbackmechanism-Usuallyreferredas"Tubuloglomerularfeedback"*Efferentarteriolefeedbackmechanism.Afferentarteriolarfeedbackmechanism:*Transmitterinvolved?AdenosinecausingCa2+channelopening.Efferentarteriolarfeedbackmechanism:*Activatesrenin-angiotensinsystemgeneratingangiotensinIIefferentarterioleconstriction?edGFR.*Feedbackdependsonjuxtaglomerularapparatus&itsspecializedcells.-Maculadensa?Specializedepitheliumofdistaltubuleinclosecontactwithafferentarteriole
175.Calcitoninlevelsincreasedin a)Hyperthyroidism b)Hyperparathyroidism c)Hypoparathyroidism d)CushingSyndrome CorrectAnswer-BAns:B.HyperparathyroidismTheserumcalcitoninlevelisstronglyincreasedinthistypeofcancer.Aftersuccessfultotalthyroidectomy,calcitoninisnolongerdetectable.Increasingconcentrationsofcalcitoninaftertherapyindicaterelapseormetastasis.Hyperparathyroidismispresentin20-30%ofpatientswithmedullarthyroidcarcinoma.
176.WhenthevaluesofFev1=1.3&FCV=3.9. Whichofthefollowingdoesthissignify? a)Normallungfunction b)Obstructivelungdisease c)Restrictivelungdisease d)Both CorrectAnswer-BAns:B.ObstructivelungdiseaseMeasurementofthebronchodilatorresponseofforcedexpiratoryvolumein1second(FEV1)isanimportantmethodinclinicalrespiratorymedicine.ThismeasurementisusedtopredicttheresponsetobronchodilatortreatmentandispartofthediagnosisofCOPDandasthma.Thebronchodilatorresponseofforcedvitalcapacity(FVC)haslessclinicalusethanthebronchodilatorresponseofFEV1butmayaddimportantclinicalphysiologicalinformationAirwayobstructionwasdefinedasFEV1/FVCratiobelowlowerlimitofnormal(LLN)beforebronchodilation,andCOPDwasdefinedasanFEV1/FVCratiobelowLLNafterbronchodilation.
177.Antegradeperistalsisdueto? a)Ach b)Serotonin c)SubstanceP d)VIP CorrectAnswer-DAns:D.VIPDefinedasamotorpatternofthegutorganmusculaturethatcanpropelcontentintotheanal(antegradeperistalsis)ororal(retrogradeperistalsis)direction.Impulsestravelingoradactivateascendingcontraction:Neurotransmittershereareacetylcholine,substanceP,andneurokininA.Impulsestravelingcaudadactivatedescendingrelaxation:NeurotransmittershereareVIP,NO,andPACAP(pituitaryadenylylcyclaseactivatingpolypeptide).
178.C-peptideseenin? a)InPre-proinsulin b)InProinsulin c)Asacombinedentitywithinsulinaftersecretion d)Agastrointestinalproactivemolecul CorrectAnswer-BAns:B.InproinsulinSynthesisofinsulin:Synthesizedaslargerpreprohormone(Pre-proinsulin)enteringER.Removalof23amino-acidsignalpeptidetakesplace.Convertedto"Prohormone-Proinsulin".Proinsulinstructure:MadeupA&Bchain,connectedbyC-peptide/chain.C-peptide?Detachedfromgranulesbeforesecretion.90%?97%insulinfromBcells.AlongwithequimolaramountsofC-peptide.
179.Inforcefulexpiration,whichofthe followingneuronsgetsfired? a)VRG b)DRG c)Pneumotaxiccentre d)Chemoreceptors CorrectAnswer-AAns:A.VRGMedullaryrespiratorygroup:Principalareasinmedullaoblongataconcernedwithrespiratoryregulation.Includes,Dorsalrespiratorygroup(DRG).Ventralrespiratorygroup(VRG).Pre-Botzingercomplex.Peripheralinputs.Dorsalrespiratorygroup(DRG):DRGneurons?Mainlyconcernedwithinspiration.Descend&terminateonspinalmotorneuronsinnervatingprimaryinspiratorymuscles.I.e.,Diaphragm&Externalintercostalmuscles.Ventralrespiratorygroup(VRG):VRGneurons?Mainlyconcernedwithforcefulexpiration.Minimalactivitiesw.r.tinspiration.Contributestobothexpiration&inspiration.
180.Slowconductionvelocityisseenwith whichofthefollowingnervefibers? a)Preganglionicautonomicnervefibers b)Postganglionicautonomicnervefibers c)Motornerves d)Sympatheticnervefibers CorrectAnswer-BAns:B.PostganglionicautonomicnervefibersErlanger&Gasserclassification:Cfiber?Characteristics:Diameter?0.2-1.0Myelination?UnmyelinatedConduction?0.2-2(minimum)Functions:Pain?Slowpain("Protopathic/Secondpain)TemperaturePressurePostganglionicautonomicfibers.Highsusceptibilityto:Localanesthetics
181.Calculatetheejectionfractionfromthe givenvolumepressurecurve: a)40% b)50% c)55% d)60% CorrectAnswer-DAns:D.60%(RefGunong25/ep54024/ep542)Ejectionfractioncalculatedfromthegivenvolumepressurecurveis60%. PressureVolumeLoop:ab:isovolumetriccontractionbc:Ventricularcontractionduringsystolecd:Isovolumetricrelaxation.Calculation:End-DiastolicVolume(EDV)(Pointa)=130mL
EndSystolicVolume(ESV)(Pointd)=50mLStrokeVolume(SV)=EDV?ESV=80mLEjectionFraction=SV/EDV=80/130=0.6i.e.%EF=60%.
182.Chemoreceptorsarelocatedinwhich area? a)Medulla b)Archofaorta c)Bifurcationofcarotidartery d)Alloftheabove CorrectAnswer-DAns.is'd'i.e.,AIIoftheaboveCentralchemoreceptors-VentralSurfaceOfMedulla.Peripheralchemoreceptors-Atbifurcationofcommoncarotidartery(carotidbody)andarchofaorta(aorticbodies)
183.HormoneresponsibleforBPregulation afterafallduetobloodloss. a)ADH b)ANP c)Epinephrine d)Aldosterone CorrectAnswer-AAns.is'a'i.e.,ADH(principlesofmedicalphysiologyp.573)Bloodpressureisregulatedbyfollowingmechanisms.ShorttermregulationThesemechanismsactimmediatelyandcorrectthebloodpressurequickly.Theseare:- 1. Baroreceptorreflex:WorksduringBprange70-150mmHg2. Chemoreceptorreflex-WorkswhenBpbelow80mmHg.3. CNSischemicresponse:ThistheonlyhopeofsurvivalwhenBPis below40mmHg.Hormonalrelease:Theseare- 1. Antidiuretichormone(ADH):Increaseswaterreabsorptionin kidney. 2. AngiotensinII:Causesvasoconstriction.
184.
Sodiumchannelsaremaximuminwhichpartofneuron? a)Soma b)Axonhillock c)Dendrites d)Axon CorrectAnswer-BAns.is'b'i.e.,AxonhillockInamotorneuron,theaxonhillockandtheinitialsegmentofaxonhavethelowestthresholdforexcitation.Thisisbecausetheyhaveamuchhigherintensityofvoltagegatedsodiumchannel.
185.Bloodsupplyofliver[m1/100g/min] a)1500-2000 b)1000-1500 c)50-60 d)250-300 CorrectAnswer-CAns.is'c'i.e.,50-60[Ref:Ganong23'd/ep.570]Bloodflowthroughvariousorgansareasfollow:-TotalBloodFlow(bloodflowtowholeorganinml/min)rLiver(1500)>kidney(1260)>skeletalmuscle(540)>Brain(750)>Skin(,162)>Heart(250).
186.Conversionofprekallikreintokallikrein requireswhichclottingfactor- a)XIII b)XII c)XI d)X CorrectAnswer-BAns.is'b'i.e.,XII[RelEssentialofmedicalphysiologyp.612]InitiationofintrinsiccoagulationpathwayoccurswhenfactorXIIisexposedtonegativelychargedsurface.ThisleadstoactivationoffactorXIItoXIIa.FactorXIIacanthenhydrolyzeprekallikreintokallikrein,whichinturnactivatesmoreXIItoXIIa.
187.Theonlyexcitatoryneuronsincerebellar cortexare? a)Purkinje b)Basket c)Golgi d)Granulecells CorrectAnswer-DAns.is'd'i.e.,Granulecells[RefBDCVol.3p92)Purkinjecellsaretheonlyoutputcellsfromcerebellarcortex.Purkinjecellssendinhibitoryefferentstodeepcerebellarnuclei.Basketcellsinhibitbodyofpurkinjecellswhilestellatecellsinhibitdendritesofpurkinjecells.Granulecellssendfacilitatoryefferentstobasket,stellateandpurkinjecellsthroughparallelfibers.Climbingfibersandparallelfibersstimulatepurkinjecells.
188.Temperaturecentreis? a)Supraopticnucleusofhypothalamus b)Paraventricularnucleusofhypothalamus c)Preopticnucleusofhypothalamus d)Suprachiasmaticnucleusofhypothalamus CorrectAnswer-CAns.is'c'i.e.,Preopticnucleusofhypothalamus[Ry'Ganong23'd/ep.275)
189.Rightingreflexisa? a)Cochlearreflex b)Spinalreflex c)Vestibularreflex d)Noneoftheabove CorrectAnswer-CAns.is'c'i.e.,Vestibularreflex[RefUnderstandingofmedicalphysiologyp.662]VestibularreflexesTheinformationcollectedbyvestibularapparatusleadsmainlytoreflexadjustmentinpostureandeyemovements.Vestibularreflexesare-ToniclabyrinthinereflexRightingreflex(labyrinthinerightingreflex)Visualreflexvestibulo-ocularreFlex)
190.Biphasicactionpotentialofmixednerve except? a)Allornonephenomenon b)Twoormorepositivepeaks c)Refractoryperiod d)Recordedonsurface CorrectAnswer-BAns.is'b'i.e.,TwoormorepositivepeaksActionpotentialwhenrecordedbyputtingtwoelectrodesonthesurfaceofaneuron(insteadofputtingonsurfaceandoneintracellularly),showsabiphasicresponse,i.e.Biphasicactionpotential.Asthewaveofdepolarizationreachedthefirstelectrode,thiselectrodebecomesnegativeandanupwarddeflection(Peak)isrecorded.Vagus,Glossopharyngeal,Facialaremixednerve.
191. Whichofthefollowingis/areeffectof increased2,3-DPGonoxygen- hemoglobindissociationcurve? a)edaffinityofheamoglobintooxygen b)edaffinityofhaemoglobintooxygen c)Leftshiftofoxygen-hemoglobindissociationcurve d)Rightshiftofoxygen-hemoglobindissociationcurve e)Nochangeinoxygen-hemoglobindissociationcurve CorrectAnswer-B:DAns.(B)edaffinityofhaemoglobintooxygen(D)Rightshiftofoxygen-hemoglobindissociationcurve[Ref:Ganong25th/ep.610-41;Guyton's12'h/ep.j56-57;AKlain6'h/ep.430]*Oxygen-hemoglobindissociationcurveis2,3DPGinRBC.*DPGisanoptionalby-productoftheglycolyticpathway.*DPGbindswithdeoxygenatedhemoglobinbutnotwithoxygenatedhemoglobin.*RaisedDPGconcentrationreleasesoxygenfromoxyhemoglobinbyshiftingthefollowingreversiblereactiontotheright.Mechanism:*OnemoleculeofDPGbindswithonemoleofdeoxyhemoglobin.*HenceanincreaseinDPGconcentrationshiftstheoxygen-hemoglobindissociationcurvetotheright.*Thus2,3DPGcausesdelivery(unloading)ofO,tothetissues.*Fetalhemoglobinhasconsiderablylessaffinityfor2,3-DPGthandoesadulthemoglobinthereforefetalhemoglobinhasagreater
affinityforoxygenthanadulthemoglobin.Inhumanblood,theaffinityoffetalhemoglobinfor2,3-DPGisonlyabout4O%thatofadulthemoglobin.Thismakesfetalhemoglobinbehaveasif2,3-DPGlevelsarelow.
192.Truestatementrelatingtocomplianceof lung: a)Increasedbysurfactant b)Decreasedinemphysema c)Atheightofinspirationcomplianceisless d)Itcanbemeasuredbymeasuringintrapleuralpressureat differentlungvolume e)None CorrectAnswer-A:C:DAns.(A)Increasedbysurfactant(C)Atheightofinspirationcomplianceisless(D)Itcanbemeasuredbymeasuringintrapleuralpressureatdifferentlungvolume[Ref:Ganong25th/629-32,24th/629-33;Guytonllth/473-75;A.K.Jain5th/437]Lungcompliance:Measuredbymeasuringintrapleuralpressureatdifferentlungvolume.Animportantfactoraffectingthecomplianceofthelungsisthesurfacetensionofthefilmoffluidthatlinesthealveoli.Deficiencyofsurfactant-lesscompliance;moresurfactant-morecompliance.Compliancedecreaseswiththeinflationofthelungsasmorepressureisrequiredtodistendthealreadydistendedlung.Thecurveisshifteddownwardandtotheright(complianceisdecreased)bypulmonarycongestionandinterstitialpulmonaryfibrosis;pulmonaryfibrosisisaprogressivediseaseofunknown
causeinwhichthereisstiffeningandscarringofthelung.Thecurveisshiftedupwardandtotheleft(complianceisincreased)inemphysema.
193.Lipidraftsareseenin? a)Ribosomes b)Mitochondria c)Plasmamembrane d)ER CorrectAnswer-CAns.C.Plasmamembrane.*LipidraftsareregionsinplasmamembranethataccumulateCholesterolandglycolipids(glycosphingolipids).-Sothereregionsareslightlythickerthanotherareasofplasmamembrane.-Becausefdistinctmolecularcompositionoflipidrafts,theycanactusmicrocompartmentwithincells,givingthecellanadditionalwaytoorganizepathways.-Involvedintheregulationofsignaltransduction.Typesoflipidrafts:*Planarlipidrafts(noncaveolarorglycolipidrafts)-Continuouswithplaneofcellmembrane(theyarenotinvaginate).Caveolae:*Specializedtypesoflipidraftswhichareflasklikeinvaginationsofplasmamembrane.*Producedwherecaveolinproteinispresentinlipidbilayermembrane.
194.Markerofendoplasmicreticulum? a)Acidphosphatase b)Glucose-6-phosphatase c)Catalase d)LDH CorrectAnswer-BAns.B.Glucose-6-phosphatase.OrganelleorfractionMarkersPlasmamembrane-Adenylcyclase,Na+ICATPaseLysosome-AcidphosphataseGolgiapparatus-Galactosyltransferase,GolgimannosidaseII,Sialyltransferase,G1cNActransferase.Endoplasmicreticulum-Glucose-6-phosphatasePeroxisome-Catalase,Urate(uricacid)oxidaseCytosol-LactatedehydrogenaseNucleus-DNARibosome-HighcontentofRNA
195.Followingisafeatureofsimple diffusion? a)Againstaconcentrationgradient b)Easyfornon-polarsubstance c)Moreinthickmembrane d)Requirescarrierprotein CorrectAnswer-BAns.B.Easyfornon-polarsubstanceSimplediffusion:Referstodiffusionofmoleculeacrossthemembranefollowingaconcentrationgradientorchemicalgradient,butwithoutthehelpofanycarrierprotein.Factorsinfluencing:A)Rateofdiffusionisdirectlyproportionate:-Concentration(chemical)gradientCross-sectionalareaofthemembranethroughwhichdiffusiontakesplaceLipidsolubilityofthesubstanceB)Rateofdiffusionisinverselyproportionate:-ThicknessofdiffusionmembraneSizeoftheparticleChargeorpolarityofsubstanceSo,simplediffusionisfavoredbysmallsize,lipidsolubilityandabsenceofpolarity(non-polarsubstance)andcharge(neutralmolecule)throughathin,largemembranewheretheconcentrationgradientismore.
196.Mostcommonmechanismfortransport intothecell? a)Diffusion b)Primaryactivetransport c)Antiport d)Cotransport CorrectAnswer-AAns.A.Diffusion.(RefPrinciplesofmedicalphysiologyp.3.)Mostimportantandmostcommonmechanismoftransportispassivediffusion.
197.TrueaboutNernstequation? a)Usedtocalculateequilibriumpotential b)Calculatedfornon-ionicsolution c)NernstpotentialforClis-90my d)Allarecorrect CorrectAnswer-AAns.A.Usedtocalculateequilibriumpotential.[Ref:Ganong24thlep.9;Principlesofmedicalphysiologyp.8]RMPvalueiscalculatedonbasisofNernstequation.Alsoreferred"Nernstpotential/Equilibriumpotential/DiffusionpotentialofK+.
198.Actiniswhichtypeofprotein? a)Fibrous b)Globular c)Both d)None CorrectAnswer-CAns.C.Both[RefPrinciplesofmedicalphysiologyp.731]Therearetwotypesofactinfilaments:F-actinFibrousproteinG-actinGlobularprotein
199.Somaticefferentofwhicharisefrom medulla? a)Oculomotor b)Trochlear c)Abducent d)Hypoglossal CorrectAnswer-DAns.D.HypoglossalGeneralsomaticefferent(motor)nucleiofHypoglossalnucleus:Itliesinmedullaandthroughhypoglossalnervesuppliesmusclesoftongue,exceptpalatoglossus.
200.Thirdorderneuronsofsensationsfrom facearisein? a)Medulla b)Spinalnucleusoftrigeminal c)Thalamus d)Brainstem CorrectAnswer-CAns.C.ThalamusGeneralsensationsfromthefacearecarriedbytrigeminalnerve.FromVPMnucleusofthalamus,thirdorderneuronsprojecttopostcentralgyrus(primarysensorycortex).
201.ECFconcentrationof1C.is150meq/L andICFconcentrationofleis5meq/L. WhatistheequilibriumpotentialforK+is? a)+60mV b)-60mV c)-90mV d)+90mV CorrectAnswer-CAns.'c'i.e.,-90mVNernstEquation?Canbeusedtofindthecellpotentialatanymomentinduringareactionoratconditionsotherthanstandard-state. E=cellpotential(V)underspecificconditionsE=cellpotentialatstandard-stateconditions\R=idealgasconstant=8.314J/mol-KT=temperature(kelvin),whichisgenerally25C(298K)n=numberofmolesofelectronstransferredinthebalancedequationF=Faraday'sconstant,thechargeonamoleofelectrons=95,484.56C/mollnQc=thenaturallogofthereactionquotientatthemomentintime.-61150
EK=log=90mV+15
202.Trueaboutheterophilicreceptors? a)InvolvedinbindingofGHtocellmembrane b)Bindtosameligand/hormone c)Involvedincelladhesion d)Allarecorrect CorrectAnswer-CAns.C.Involvedincelladhesion[RefTextbookofclinicalpathologyp.1132]Cell-cellandcell-tissue-interactionsoccurthroughfollowingtypesofreceptors:Homophilic&heterophilicreceptors.Heterophilicreceptors:Thesereceptorsrecognizedistinctligands(calledadhesionepitopes)ofopposingcellmembranesortissue(called"lockandkeybonds"or"links").
203.Nernnstequationrelatedtoequilibrium potentialdoesnotdependupon? a)Concentrationgradient b)Electricgradient c)Non-ionicsolution d)Concentrationofionsintwosolution CorrectAnswer-CAns.C.Non-ionicsolution[RefGuyton12th/ep.50;Principlesofmedicalphysiologyp.8]Nernstequationisforionicsolution.
204.DuetoDonnan-Gibbseffect? a)ConcentrationofK.isgreaterinECF b)ConcentrationofclisgreaterinECF c)TotalionsaremoreinICF d)Allaretrue CorrectAnswer-CAns.C.TotalionsaremoreinICF[RefPrinciplesofmedicalphysiologyp.7]Gibbs-Donnanequilibrium:Themammaliancells(intracellularfluid)containsnon-diffusibleanionlikeproteinsandorganicphosphatewhereasK'andCl-arediffusiblecationandanion,respectively.TheECFcontains1K+andCl-asdiffusiblecationandanionrespectively.DuetoGibbs-Donnanequilibrium:-ConcentraionofCl-isgreaterinICFthanECF(concentrationofdiffusiblecationisgreaterincompartmentwithnon-diffusibleanion).ConcentrationofClisgreaterinECFthanICF.TotalnumberofionsisgreaterinICFthanECF.Alltheseeffectshelptomaintaintheshapeandvolumeofcellsbydistributingdiffusibleionsacrossthemembraneaccordingtophysiologicaldemand.
205.ATPaseiswhichtypeofpump? a)Secondaryactive b)Electrogenic c)Symport d)Alloftheabove CorrectAnswer-BAns.B.Electrogenic[RefGanong24th/ep.51,10;Guyton12th/ep.53]Sodium-potassiumpump:*Mostimportantpumpforprimaryactivetransportinbody.*AnElectrogenicpump.*ResponsibleformaintainingNa+&K+conc.differenceacrosscellmembrane.Mechanism:*ICF-HighK+concentration.*ECF-HighNa+concentration.*BothNa+&K+transportedagainstconcentrationgradient.*UsesenergybyhydrolyzingATP;Functions:*PumpcontainsATPaseactivity.*Na+-K+pumpextrudes--3Na+outfromcell.-Pumps2K+intocell.-CouplingratioofNa+-K+pump-3:2.
206.Diffusionrelatedto02transportacross respiratorymembraneisanexampleof? a)Simplediffusion b)Facilitateddiffusion c)Activediffusion d)Osmoticdiffusion CorrectAnswer-AAns.A.Simplediffusion.[Ref.Ganong25thlep.51&24thlep.53]Simplediffusion-Movementoffats,oxygen,CO,throughlipidportionofmembrane.Facilitateddiffusion-Movementofglucoseandsomeamino-acids.Primaryactivetransport-IonsK+,Na*,Secondaryactivetransport-Glucoseororamino-acidintothecellalongNa`(Sympoftorcotransport)1-1+outofthecellagainstNa+(Antiportorcountertransport).
207.Apnea-hypopneaindexisusedfor? a)Emphysema b)Asthma c)Hyalinemembranedisease d)Obstructivesleepapnea[OSAI CorrectAnswer-DAns.D.Obstructivesleepapnea[OSAI[RefHarvarded]ApneaHypopneaIndex(AHI)TheAHIisthenumberofapneasorhypopneasrecordedduringthestudyperhourofsleep.Itisgenerallyexpressedasthenumberofeventsperhour.BasedontheAHI,theseverityofOSAisclassifiedasfollows:None/Minimal:AHI<5perhourMild:AHI5,but<15perhourModerate:AHI15,but<30perhourSevere:AHI30perhour.
208.Measurementofintracellularfluidina50 yearsoldmaleisdoneby? a)Dilutionmethod b)Evansblue c)D20 d)Indirectly CorrectAnswer-DAns.D.Indirectly.[RefGanong23th/ep.3-6;Guyton12th/ep.286-288]Mostofthefluidiscalculateddirectlybydilutionmethod,exceptforintracellularfluid(ICF)andinterstitialfluid.Boththesearecalculatedindirectlybycalculatingotherbodyfluids.ICF=Totalbodywatervolume-ECFvolumeInterstitialfluid=ECFvolume-Plasmavolume.
209.Calculationofinterstitialfluidina50 yearsoldisdoneby? a)TBWminusECF b)ECFminusplasmavolume c)ICFminusECF d)TBWminusICF CorrectAnswer-BAns.B.ECFminusplasmavolume.[RefGanong23th/ep.3-6;Guyton12th/ep.286-288]Mostofthefluidiscalculateddirectlybydilutionmethod,exceptforintracellularfluid(ICF)andinterstitialfluid.Boththesearecalculatedindirectlybycalculatingotherbodyfluids.ICF=Totalbodywatervolume-ECFvolumeInterstitialfluid=ECFvolume-Plasmavolume.
210.Hypercoagulablefactoris? a)ProteinC b)ProteinS c)FactorVLeiden d)AntithrombinIII CorrectAnswer-CAns.C.FactorVLeiden[RefTextbookofclinicalhematologyp.786]FactorVLeidenisthemostcommoninheritedhypercoagulablestate.Occurswhenaspecificmutationinaproteinthatismoreresistanttobeturnedoff,leadingtoanincreasedriskofthrombosis.
211.Excitabilityofcellsismaximallyaffected bychangeinconcentrationofwhichion? a)IC+ b)Na* c)a- d)Ca+2 CorrectAnswer-DAns.D.Ca+2[RefPrinciplesofmedicalphysiologyp.801]Effectsofionconcentrationchangeonmembranepotential:*Hypercalcemia-AnincreaseinextracellularCa2+concentrationcanstabilizethemembranebydecreasingexcitability.*Hypocalcemia-Calciumionismembranestabilizers.-AdecreaseinextracellularCa2+concentrationincreasestheexcitabilityofnervebydecreasingtheamountofdepolarizationnecessarytoproducetheactionpotential.-Hyperexcitabilityisseen.
212.InhibitionofNa*ATPaseleadsto? a)DecreasedNa*inthecell b)IncreasedCa'inthecell c)IncreasedK*inthecell d)IncreasedCl-inthecell CorrectAnswer-BAns.B.IncreasedCa'inthecell[RefPrinciplesofmedicalphysiology3rdlep.786]3Na+/1Ca+exchanger(Sodium/Calciumexchangepump):Itmoves3Na+intothecellinexchangeoneCa+goingout
213.Non-specificpainpathwayisfor? a)Nociceptivepain b)Neuropathicpain c)Idiopathicpain d)Inflammatorypain CorrectAnswer-CAns.C.Idiopathicpain[RefTextbookofpsychotherapyp.6]Painmaybedividedinto:-Nociceptivepain:Itismusculoskeletalpainthatresultsfrominjuryorinflammatoryordegenerativedisorders,e.g.bonefractureorarthritisorburn.Neuropathicpain:Itisduetodysfunction/damageofnerves,e.g.prolapseintervertebraldisc.Mixedpain:Ithascomponentsofbothnociceptiveandneuropathicpains.Idiopathicorunspecifiedpain:Itispurelypsychologicalinnatureandisthereforecalledpsychogenicpain.
214.Shortestphaseofsexualcycle? a)Excitementphase b)Plateuphase c)Orgasmicphase d)Resolution CorrectAnswer-CAns.C.Orgasmicphase[RefOxfordtextbookofpsychiatryp.227]Orgasmphase:PrematureejaculationoccursinthisphaseReflexivemusclecontractionoccursinpelvisItistheshortestphaseandlastsonlyafewseconds
215.Dullvisceralpainiscarriedbywhich typeofneurons? a)Agamma b)Aa c)Cfibres d)B CorrectAnswer-CAns.C."C"fibers.[RefGanong24th\ep.92&23rdlep.89]Aviscusdoesnothaveanyothersensation(e.g.touch,temperatureetc)exceptpain.Duetosparsedistributionofpainreceptors,visceralpainispoorlylocalized.Visceralpainsensationiscarriedbytype-Cafferentsinthesympatheticsystem(fromthoracicandabdominalviscera)andparasympatheticsystem(frompelvicviscera).
216. Erectionofpenisoccursinwhichphase ofsexualcycle? a)Excitementphase b)Plateuphase c)Orgasmicphase d)Resolution CorrectAnswer-AAns.A.ExcitementphaseRefOxfordtextbookofpsychiatryp.227]ExcitementphaseThereisincreasedphysiologicalexcitementsuchashighBPandheartrate.Thereiserectionofpenis(inmales)andswellingofclitoris&labiaminora(infemales).Testesswell,scrotumtightensThereisvaginallubrication
217.'C'fiberscarrysensationsthroughwhich pathway? a)Posteriorcolumn b)Anteriorspinothalamictract c)Lateralspinothalamictract d)Alloftheabove CorrectAnswer-CAns.C.Lateralspinothalamictract.[RefGanong23rdiep.648;Goyton12thlep.573].CfiberscarryPain(slowpain)andtemperaturesensation.Thesearecarriedbylateralspinothalamictract.
218. Prematureejaculationoccursinwhich phaseofsexualcycle? a)Excitementphase b)Plateuphase c)Orgasmicphase d)Resolution CorrectAnswer-CAns.C.Orgasmicphase[RefOxfordtextbookofpsychiatryp.227]Orgasmphase:PrematureejaculationoccursinthisphaseReflexivemusclecontractionoccursinpelvisItistheshortestphaseandlastsonlyafewseconds
219.TypesCnervefibersare? a)Sensory b)Motor c)Mixed d)Anyoftheabove CorrectAnswer-AAns.A.sensory.TypeCfibers:Postganglionicautonomicfibers.Sensoryfunctionafferenttotemperature&pressure.Nomotorfunction.
220.Exercisemediatedincreaseinmuscular bloodflowismediatedbywhichsympatheticfibers a)Adrenergic b)Noradrenergic c)Dopaminergic d)Cholinergic CorrectAnswer-DAns.D.CholinergicAnexerciseisaformofstress,andlikemoststresses,isaccompaniedbysympatheticoveractivity.Skeletalmuscleshavebothsympatheticnoradrenergicvasoconstrictorfibersandsympatheticcholinergicvasodilatorfibers.Vasoconstrictornervefibersactmainlyonveins.Venoconstrictionimprovesvenousreturnandhelpsinimprovingcardiacoutput.Ontheotherhand,sympatheticcholinergicfibers,whichareuniquetoskeletalmuscles,bringaboutarteriolardilatationandtherebyincreasemusclebloodflow.
221.
Phosphate/phosphorusispresentinwhichpartofcell? a)Cellmembrane b)DNA c)RNA d)Alloftheabove CorrectAnswer-DAns.D.Alloftheabove[RefPrinciplesofmedicalphysiology/ep.116]PhosphorusisacomponentofDNA,RNA,ATPandalsothephospholipidsthatformallcellmembranes.NearlyeverycellularprocessthatusesenergyobtainsitintheformofATP.Thus,itisanessentialelementforalllivingcellsandimportantforenergyutilizationinthebody.
222.Warmthsensationiscarriedby? a)Aafibers b)A(3fibers c)Ayfibers d)ASfibers CorrectAnswer-AAns.a.Aafibers[RefGanong25"Yep.94&24"lep.92;Principlesofphysiologyp.512]Temperature(warmth/cold)sensationiscarriedbyA&Cfibers.
223.Trueaboutmyosin? a)Thinfilament b)Coversactivesiteofaction c)HasATPaseactivity d)Ca'bindingprotein CorrectAnswer-CAns.C.HasATPaseactivity[RefGanong241thlep.100,102]Theshorteningofmusclefiberoccursduetoslidingofactinfilamentsonmyosinfilament.However,therearefourmuscleproteinsinvolvedintheprocess:-Actin,Myosin,Tropomyosin,andtroponin.Myosin:Myosinistheproteinthatconstitutesthethickfilaments.Myosinofskeletalmuscleismyosin-II.MyosinparticipatesinthecontractilemechanismandalsoactsasanATPase.
224.
Maximumstorageofmagnesiumoccursin whichpartofbody? a)Adiposetissue b)Skeletalmuscles c)Blood d)Bone CorrectAnswer-DAns.D.Bone[RefPrinciplesofmedicalphysiologyp.114]Anadultcontainsapproximately25gramsofmagnesium.About60%ofthemagnesiumispresentinbone,ofwhich30%isexchangeableandfunctionsasareservoirtostabilizetheserumconcentration.About20%ispresentisskeletalmuscles,19%inothersofttissuesandlessthan1%inECF.
225.Incardiacmuscles,T-tubulesarepresent at? a)Zlines b)Alines c)Ilines d)A-Ijunction CorrectAnswer-AAns.A."Z"lines.[RefPrinciplesofmedicalphysiologyp.794]Thecardiacmusclecellcontainsactin,myosinthesarcotubularsystemandotherorganellesseeninskeletalmuscles.However,theTsystemofcardiacmuscleislocatedatZlinesratherthanatA-Ijunction,whereitislocatedinskeletalmuscles.
226.Tissefactoractivates? a)Preaccelerin b)Hagemanfacter c)Labilefacter d)Prothrombin CorrectAnswer-AAns.A.Preaccelerin[RefGanong23rdlep.531-535]Preaccelerin(factorVII)isactivatedtofactorVilabytissuefactor.TissuefactoristhecofactorforbothfactorVIIandVila.
227.Tissuefactoractivates? a)Intrinsicpathway b)Contactpathway c)Invitropathway d)Invivopathway CorrectAnswer-DAns.D.Invivopathway[RefGanong23thiep.5.31-53.5]Bloodcoagulationpathwaysaredividedinto:-Intrinsicpathway(contactpathway):Itislargelyan'invitro'pathwayandisactivatedwhenfactorXII(Hagemanfactororcontactfactor)comesincontactwithnegativelychargedsurface,e.g.glass,kaolinetc.Extrinsicpathway:Itislargelyaninvivopathwayisactivatedbytissuefactor(thromboplastin)atthesiteoftissueinjury.
228.Inamusclefiberatrest,thelengthofthe Ibandis1mmandAbandis1.5mm.Whatisthelengthofthesarcomere a)0.5mm b)2.5mm c)3.5mm d)5mm CorrectAnswer-BAns.B.2.5mm.SarcomereistheportionofmyofibrilbetweentwoZlines.Thus,lengthofsarcomereingivenquestion=0.5mm(1/2Iband)+1.5mm(Aband)+0.5mm(1/2Iband)=2.5mm.
229.HormonewhichaffectsIC*ion concentration? a)GH b)Thyroxine c)Insulin d)Estrogen CorrectAnswer-CAns.C.Insulin[RefGuytonIlth/ep.710]InsulinlowersserumIC'concentrationi.e.,causeshypokalemia.ThehypokalemicactionofinsulinisduetostimulationofK+intakebythecellsmainlyinmuscleandadiposetissue.InsulinincreasestheactivityofNa+-K.ATPaseincellmembrane,sothatmoreK+ispumpedintocells.
230.Whitefibersarepresentinwhich muscle? a)Calfmuscles b)Backmuscles c)Glutealmuscles d)Handmuscles CorrectAnswer-DAns.D.Handmuscles.[RefPrinciplesofmedicalphysiologyp.118]Typeofmusclefibers:Type1(red)ortype2(white).Mostofthemuscleinhumanbodycontainsbothtypesoffibers,i.e.mostmusclesinthebodyhavebothtypesofmotorunits.But,somemuscleshavemoretype1fibers(type1motorunits)thantype2,andvice-versa.Accordingly,skeletalmusclescanbedividedinto:RedmusclesThesemusclescontainmoretype1(red)fibers,thereforeareslowtwitchmusclesandcontainmoremyoglobincontent.Thesearemuscleswhichrequireprolongedcontraction,forexample,muscleswhichhelpinmaintainingposture,i.e.Backmusclesgluteusmuscles(atbackofhip)andcalfmuscles.White(pale)musclesThesemusclescontainmoretype2(white)fibersandarefasttwitchmuscles.Thesearemuscleswhichhelprapidcontractionsandfinermovements.ExamplesareHandmusclesandextraocularmuscles.
231.Functionofmusclespindleis? a)Movementofalimb b)Muscletonemaintenance c)Goalorientedmusclecontraction d)Alloftheabove CorrectAnswer-BAns.B.Muscletonemaintenance[RefUnderstandingofmedicalphysiologyp.138]Ifaskeletalmuscleisstretched,itrespondbycontracting.Inotherwords,ifamuscleisstretched,ittendstobecomeshorterandmorestiff,therebyresistingstretch.Thisisbecauseofreceptorsensitivetostretchwithinthemuscle.Stretchreceptorwithinamuscleiscalled"musclespindles".Stretchreflexhastwoprincipalfunctions:1)TomaintainmuscletoneToneisatendencyofamuscletoresistbeingstretched.Muscletoneisnotonlyimportantformaintainingposturebutalsofacilitateslocomotionandmakesallvoluntarymovementsmooth.2)Tomakemusclesrespondtostretchandrelease.
232.Afferentsforstretchreflexesarecarried bywhichfibers? a)Aa b)Ay c)TypeB d)TypeC CorrectAnswer-AAns.A.Aa[RefGanong24th/ep.229]Sensoryinnervation(afferent)ofmusclespindle:Twotypesofsensorynervefibers(afferent)originatefromtheintrafusalfibers:Annulospiral(Primary)endingarewoundaroundthecentralregionofbothnuclearbagfiberandnuclearchainfiber.TheseareA(orI)fibers.Flower-spray(Secondary)endingsinnervatetheperipheralparts(ends)ofnuclearchainfiber.TheseareAor(orII)fibers.
233.Allaretrueregardingintracellular receptors,except? a)Actbyregulatinggeneexpression b)Fastestactingreceptors c)Glucocorticoidreceptors d)DNAcontainshormoneresponsiveelements CorrectAnswer-BAns.B.Fastestactingreceptors[RefGanong24thlep.406;Harper28th/ep.4281]Thisisslowestactingtranductionmechanismbecauseproteinsynthesistakessometime.
234.Spinalcordhashowmanysynapsesin golgitendonreflex? a)1 b)2 c)3 d)4 CorrectAnswer-BAns.B.2[Ref:Principlesofmedicalphysiologyp.786]StrechreflexthroughmusclespindleMonosynapticGolgitendonreflexBisynaptic.
235.Secretionofcortisolishighestat? a)Mid-night b)Earlymorning c)Afternoon d)Evening CorrectAnswer-BAns.B.Earlymorning[RefTextbookofclinicalendocrinologyp.78]ThesecretionofACTHandconsequentlythatofcortisolfollowsacircadianrhythmduetohypothalamic(Suprachiasmaticnucleus)control.ACTHsecretionisminimumduringnightandmaximumearlyinthemorning(6-8am).
236.Inversestretchreflexisa? a)Monosynapticreflex b)Bisynapticreflex c)Polysynapticreflex d)Nonsynapticreflex CorrectAnswer-BAns.B.Bisynapticreflex[RefPrinciplesofmedicalphysiology3rd/ep.786]Golgitendonreflex(inversestretchreflex)isbisynapticreflex.
237.TrueaboutACTHandcortisol [corticosteroid]secretion? a)Maximumsecretionintheevening b)ACTHhasnegativefeed-backcontrol c)ACTHhasmajoreffectonmineralocorticoidsecretion d)ACTHisderivedfromPOMC CorrectAnswer-B:DAns.B&D.ACTHhasnegativefeed-backcontrol(D)ACTHisderivedfromPOMC[RefUnderstandingsofmedicalphysiologyp.539]ACTHisderivedfromprecursormoleculepro-opiomelanocortin(POMC).ACTHstimulatestheadrenalcortextoincreasethesynthesisandreleaseofglucocorticoids.Atnormalphysiologicalconcentration,theeffectofACTHonsecretionofmineralocorticoid(aldosterone)andandrogenisminimal.However,athigherconcentrationsynthesisandreleaseofthesehormonecanalsoincrease.ThesecretionofACTHissubjectedtonegativefeedback(inhibition)byglucocorticoids.ACTHsecretionshowsdiurnal(circadian)rhythmwithminimumsecretionateveningandmaximumsecretionatearlymorning.
238.Facilitatorypresynapticneurotransmitter is? a)GABA b)Glycine c)Glutamate d)Aspartate CorrectAnswer-C:DAns.is'c>d'i.e.,Glutamate>Aspartate[RefUnderstandingofmedicalphysiology1"/ep.412]Glutamateisthechiefexcitatoryneurotransmitterinthebrainandspinalcord.Aspartateseemstobethechiefexcitatoryneurotransmitterofcorticalpyramidalcells.
239.Geneforinsulinresponsiveglucose transporterislocatedonchromosome? a)7 b)21 c)17 d)13 CorrectAnswer-CAns.C.17[RefPrinciplesofmedicalphysiologyp.790]GLUT-4isresponsibleforfacilitatingthetransportofglucoseintothecellsinresponsetoinsulin.Forthisreason,mutationinGLUT-4havebeenassociatedwithtype2diabetes.TheGLUT-4geneislocatedonshortarmofchromosome17(17p13).
240.Glucosetransporteraffectedindiabetes mellitus? a)GLUT-2 b)GLUT-5 c)GLUT-4 d)SGLT-2 CorrectAnswer-CAns.C.GLUT-4[RefPrinciplesofmedicalphysiologyp.790]GLUT-4isresponsibleforfacilitatingthetransportofglucoseintothecellsinresponsetoinsulin.Forthisreason,mutationinGLUT-4havebeenassociatedwithtype2diabetes.TheGLUT-4geneislocatedonshortarmofchromosome17(17p13).
241.
Nissl'sgranulesarefoundinwhichpartofnervecell- a)Axonhillock b)Axons c)NodeofRanvier d)Body CorrectAnswer-DAns.D.Body[RefChaudhri7h/ePrinciplesofmedicalphysiology-7]NisslBodies(Nisslgranuleortigroidbody):Nisslbodiesarelargegranularbodyfoundinneuron.Presentalloverthesoma(body),exceptingaxonhillockandtheyextendtosomeextentinthedendrites,butnotwithintheaxon.Thesegranulesareroughendoplasmicreticulumwithfreeribosomesandarethesiteofproteinsynthesis.Theyarethoughttobeinvolvedinthesynthesisofneurotransmittersuchasacetylcholine.Nisslbodiesarebasophilicgranules.Chromatolysis(disappearanceofNisslbodies)isanimportanthistologicalsignofneuronalinjury.Whenthedemandoftheproteinsynthesisisgreatthenisslgranulesoverworkandmanyaltogetherdisappear(chromatolysis).
242.Stereociliaarefoundin? a)Eye b)Nose c)Tongue d)Epididymis CorrectAnswer-DAns.D.Epididymis*Stereociliaarefoundinthreeplaces-Haircellsofinnerear-Epididymis-Ductusdeferens.
243.Mechanismofactionof5-areductase? a)BreakageofC4C5doublebond b)BreakageofC-Nbond c)Breakageofamidebond d)BreakageofN-Nbond CorrectAnswer-AAns.A.BreakageofC4C5doublebond5-alphareductasecausesreduction(breakge)ofC4-05doublebond(A4.5)withthehelpofNADHasacofactor.Itconverts(reduces)testosteronetodihdrotestosterone.
244.Stereociliaarepresentin? a)Tastebuds b)Haircells c)Retina d)Nose CorrectAnswer-BAns.B.Haircells.[RefGanong25th/ep.202]Haircellshaveacommonstructure.ThetallesthaircelliscalledasKinociliumandtheprogressivelyshorterhaircellsarecalledasStereocilia.Thesehaircellsareconnectedtogetherbytiplinkswhichhasmechanicallysensitivecationchannels.
245.CSFpressureisincreasedinallexcept- a)Forcedinspiration b)Coughing c)Valsalvamanoeuvre d)Crying CorrectAnswer-AAns.A.Forcedinspiration.[RefEssentialofmedicalphysiologyp.950]Eventslikecoughing,valsalvamanoeuvre,andcryingincreasethepressurebydecreasingabsorption.CompressionofIJV(internaljugularvein)alsoraisestheCSFpressure.
246.cAMPactivates? a)Proteinkinase'A' b)Proteinkinase'C' c)Nucleartranscription d)Phospholipare CorrectAnswer-AAns.A.Proteinkinase'A'Hormonesactingthroughadenylylcyclase(AC):Corticotropinreleasinghormone(CRH),FSH,LH,TSH,ACTH(corticotropin),ADH,Vasopressin(V2receptors),Parathormone,Catecholamine)e.g.,adrenaline(mostactions),Glucagon,hCG,Calcitonin,Somatostatin,acetylcholine(M2),Dopamine(1),AngiotensinII(epithelialcells),GABA-B,Histamine(H2).
247.CSFispresentinwhichspace? a)Centralcanalofspinalcord b)Ventriclesofbrain c)Subarachnoidspace d)Alloftheabove CorrectAnswer-DAns.D.Alloftheabove.[RefGanong24th/ep.603;Principlesofmedicalphysiologyp.293]*Cerebrospinalfluid(CSF)isaclear,colorless,almostproteinfreefiltrate(transduate)ofblood.*Itispresent,-Aroundthebrain(insubarachnoidspace)andinsidethebrain(initsventricles).-Aroundthespinalcord(insubarachnoidspace)andinsidethespinalcord(initscentralcanal).
248.Maximumdailydegradationof hemoglobininnormaladults? a)2gm b)4gm c)6gm d)8gm CorrectAnswer-DAns.D.8gmAtotaldailyexcretionof140mgofurobilinogenwouldrepresentthecatabolismof3.99gramsofhemoglobin.Normalmaximumurobilinogeninfecesis280mg,i.e.8gramsofhemoglobincatabolism.
249.Dailyfecalurobilinogenexcretionin healthyadults? a)20-40gm b)40-280gm c)20-40mg d)40-280mg CorrectAnswer-DAns.D.40-280mg[Ref:Principlesofmedicalphysiologyp.212]Thenormaldailyexcretionofurobilinogeninthefecesrangesfrom40to280mg,averaging150mg.Atotaldailyexcretionof140mgofurobilinogenwouldrepresentthecatabolismof3.99gramsofhemoglobin.
250.FunctionofGhrelin? a)Stimulatewaterabsorption b)Increaseappatite c)Regulationoftemperature d)Stimulatelipogenesis CorrectAnswer-BAns.B.Increaseappatite[RefClinicalendocrinologyp.48;Ganong24th/ep.487]*Ghrelinisapeptidesecretedbyoxynticcellsingastricfundusthatarecharacterizedbyround,compact,electron-densesecretorygranules.*Ghrelinpromotesfoodintake,i.e.,stimulateappetite(orexigenic).*Increaseswithanorexia.*Inhuman,ghrelininduceslipolysis.*Ghrelinisreleasedfromthestomachinfastingstate.-Increaseshungerbyinhibitingtheventromedialhypothalamus(satietycenter).-StimulatesGHsecretions.
251.Locationofvisualcortex? a)Precentralgyrus b)Postcentralgyrus c)Sylvianfissure d)Calcarinesulcus CorrectAnswer-DAns.D.Calcarinesulcus[RefPrinciplesofmedicalphysiologyp.531]Theoccipitallobeisthevisualprocessingcenterofbraincontainingmostoftheanatomicalregionofvisualcortex.Primaryvisualareaisbrodmannarea17(alsocalledVI)onmedialsideofoccipitallobeincalcarinesulcus.Itisalsocalledasstriateareaorstriatecortexbecauseitcanbeidentifiedbyalargestripeofmyelin,thestriaofgennari.
252.Parvocellularpathwayforvisionis concernedwith? a)Finedetailsofobject b)Movementsofobject c)Flickeringfeatures d)Depthofvision CorrectAnswer-AAns.A.Finedetailsofobject[RefGanong24th/ep.190]Parvocellularpathway(arisesfromlayer3,4,5,6ofLGB).Axonsfromparvocellularterminateinlayer4ofthevisualcortex.Parvocellularpathwaycarriessignalsforcolorvision,texture,shapeandfinerdetails.
253.Sweatglandsaresuppliedbyallexcept? a)Cholinergicneurons b)Sympatheticneurons c)Adrenergicneurons d)C-fibers CorrectAnswer-CAns.C.Adrenergicneurons[RefUnderstandingofmedicalphysiologyp.786]Nervesupplyofsweatglandisuniqueinthatitissympatheticbutcholinergic(mostothersympatheticsitesarenoradrenergic).Post-ganglionicsympatheticfibersareType-Cfibers.
254.Gustatorypathwayinvolveswhich nerve? a)Facial b)Glossopharyngeal c)Vagus d)Alloftheabove CorrectAnswer-DAns.D.Alloftheabove[RefPrinciplesofmedicalphysiologyp.87]Fibersinnervatingtastebudsarebranchesofcranialnerves,i.e.,branchesoffacial,glassopharyngeal,andvagusnerves.Thetastebudsintheanteriortwo-thirdsofthetongueareinnervatedbylingualbranchesofthefacialnerve.Thetastebudsintheposteriorthirdofthetongueareinnervatedbyglossopharyngealnerve.Tastereceptorsinthepharyngealpartoftongueandonthehardpalate,softpalate,andepiglottisareinnervatedbyfibersofthevagusnerve.
255.TrueaboutbasicrhythmofGIT? a)Fluctuatebetween-65and-40mV b)Initiatedbyzymogencells c)Pacemakercellsarepresentinproximalstomach d)Alloftheabove CorrectAnswer-AAns.A.Fluctuatebetween-65and-40mV[RefPrinciplesofmedicalphysiologyp.915]Thesmoothmusclecellsofgastrointestinaltracthasspontaneousrhythmicfluctuationsinmembranepotentialbetweenabout-65and-45mV.Thisiscalledbasicelectricalrhythm(BER).ThisBERisinitiatedbypacemakercellscalledintersititialcellsofCajal.
256.Functionofcerebellum? a)Regulationoftone b)Coordinationofeyemovement c)Planning&initiationofmovement d)Alloftheabove CorrectAnswer-DAns.D.AlloftheaboveFunctionsofthecerebellum:Regulationoftone,postureandequilibrium.Smootheningandcoordinationofvoluntarymovements.Themostimportantfunctionandthebestknownfunctionofcerebellumiscoordinationofmovements.CoordinationofeyemovementsPlanningandinitiationofmovementsLearningoffrequentlyperformedvoluntarymovements.Timingandcomparison:Thecerebellumisbelievedtobeatimingdevicethattimesthedurationofagonisticmuscleactivityandlatencyofantagonisticactivity,Sothatanymovementishaltedatthecorrectpoint.
257.Whichofthefollowingisnota metabotropicreceptorforserotonin? a)5HT,A b)5HT,13 c)5HT2A d)5HT3 CorrectAnswer-DAns.D.5HT3[Ref:Ganong32p.139;Principlesofmedicalphysiologyp.786]Metabotropicreceptors:AreG-proteincoupledreceptorswhichactthroughsecondmessenger.Serotoninincluded:Withtheexceptionofthe5-HT3receptor,aligandgatedionchannel,allother5-HTreceptors.
258.Twopointdiscriminationismainlya functionofwhichtouchreceptors? a)Merkel'sdisc b)Ruffini'sendorgan c)Pacciniancorpuscle d)Meissner'scorpuscle CorrectAnswer-AAns.A.Merkel'sdisc[RefPrinciplesofmedicalphysiologyp.647]Tactile(touch)receptorsFortouch(superficaltouch):-Meissner'scorpuscle(detecttextureofsurface,i.e.roughorsmooth),Merkel'sdisc(detecttwopointdiscrimination).
259.Whichofthefollowingdefinesvital capacity? a)Airinlungafternormalexpiration b)Maximumairthatcanbeexpiratedafternormalinspiration c)Maximumairthatcanbeexpiratedaftermaximuminspiration d)Maximumairinlungafterendofmaximalinspiration CorrectAnswer-CAns.C.MaximumairthatcanbeexpiratedaftermaximuminspirationVitalcapacity(VC):4700ml.Amountofairthatcanbeexhaledwithmaximumeffortaftermaximuminspiration(ERV+TV+IRV).Usedtoassessstrengthofthoracicmusclesaswellaspulmonaryfunction.
260. Whichofthefollowingactsas "Gatekeeper"intheGIT? a)Na+-aminoacidcotransporter b)Na+K+ATPass c)Calciumchannel d)Ne-glucosecotransporter CorrectAnswer-CAns.C.Calciumchannel[Refwww.ncbi.nlm.nih.gov]Epithelialcalciumchannels(ECaCs)actas'gatekeeper'fortransepithelialCa"transport.PrimetargetforhormonalcontrolofactiveCa(2+)fluxfromtheurinespaceorintestinallumentothebloodcompartment.ThisreviewcoversthedistinctivepropertiesofthesehighlyCa(2+)-selectivechannelsandhighlightstheimplicationsforourunderstandingoftheprocessoftransepithelialCa(2+)transport.
261.Functionalresidualcapacityinnormal adultis? a)500ml b)1200ml c)2400ml d)3200ml CorrectAnswer-CAns.C.2400ml[Ref:Ganong24th/ep.629-631]Volumeofairinthelungsattheendofanormalexpiration.Inotherwords,FRC=ERV+RV.About2400ml.
262.Whatismaximumvoluntaryventilation? a)Amountofairexpiredinonemunuteatrest b)Maximumamountofairthatcanbeinspiredandexpiredinone minute c)Maximumamountofairthatcanbeinspiredperbreath d)Maximumamountofairremaininginlungafterforcedexpiration CorrectAnswer-BAns.B.Maximumamountofairthatcanbeinspiredandexpiredinoneminute[RefGuyton12th/ep.472,473;Ganong24th/ep.633]Maximumvoluntaryventilation(MVV):Itisthemaximumamountofairthatcanbemovedintoandoutofthelungsin1minutebyvoluntaryeffort.About125-170L/min.
263.Iftheileumisexcised,whatwillincrease instool? a)Bilesalts b)Bileacids c)Iron d)Calcium CorrectAnswer-AAns.A.BilesaltsBile(Majorconstituentbilesalts)isabsorbedinterminalileum.Ironandcalciumareabsorbedinduodenum.
264.TrueaboutCarboxyhemoglobin? a)Takeup02veryquickly b)Causeshistotoxichypoxia c)CausesleftshiftofHb-02dissociationcurve d)Allaretrue CorrectAnswer-CAns.C.CausesleftshiftofHb-02dissociationcurve[RefUnderstandingofmedicalphysiologyp.173].COHbcannottakeup02;liberatesCOveryslowlyandshiftsdissociationcurveofremainingHbO,toleft,decreasingtheamountof02released.COpoisoningcausesanemichypoxiabecausetheamountofHbthatcancarryO2,isreducedbutthetotalHbamountofbloodisunaffectedbyCO.
265. MaximumfatabsorptioninGItract occursin? a)Duodenum b)Jejunum c)Ileum d)Calcium CorrectAnswer-BAns.B.JejunumAfterfatdigestion,fattyacidsandmonoglyceridesareabsorbedinsmallintestineespeciallyinthejejunumandsomeamountalsoinileum.Insidetheenterocyte,fattyacidsandmonoglyceridesagainformtriglycerides.Thesetriglyceridesareincorporatedintochylomicronsandtransportedtolymphaticsandfromtheretobloodvessels.
266.WhatisthedifferencebetweenHb-0 dissociationcurveandHb-COcurve? a)COshiftsthecurvetoleft b)COhasmoreaffinitytoHb c)Co-Hbcurveissimilarto02-Hbcurve d)Allaretrue CorrectAnswer-DAns.D.Allaretrue[RefUnderstandingsofmedicalphysiologyp.786]COHbcannottakeup02;liberatesCOveryslowlyandshiftsdissociationcurveofremainingHb02toleft,decreasingtheamountofO2,released.TheaffinityofHbforCOis200-250timesitsaffinityfor02.SoCO-Hbdissociationcurveisalmostidenticalto02Hbdissociationcurveexceptthatpartialpressureareatalevelof1/250.
267.NottrueaboutBohreffect? a)Decreaseaffinityof02byincreasePCO, b)LeftshiftofHb-02dissociationcurve c)ItisduetoH* d)Allaretrue CorrectAnswer-BAns.B.LeftshiftofHb-02dissociationcurve[RefGanong24th/ep.644,Understandingofmedicalphysiologyp.789]Bohreffect:IncreaseinPCO2decreasesthe02affinitytohemoglobinandshiftstheoxygendissociationcurvetoright;itiscalledBohreffect.TheeffectofraisedPCO2ismediatedbyincreaseinhydrogenionconcentration.Hydrogenionsshiftthecurvebybindingwithhemoglobin.Deoxygenatedhemoglobin(Deoxyhemoglobin)bindsII'moreactivelythandoesoxygentatedhemoglobin(oxyhemoglobin).Ionsbindtodeoxyhemoglobinandreducetheaccessibilityofoxygentohaemgroups.Thatiswhyinthepresenceofmorehydrogenions,lessoxygencancombineswithhemoglobinatagivenP02andtheoxygendissociationcurveshiftsrightward.
268.Trueaboutaquaporinsareallexcept? a)Protein b)Aquaporin-1inPCT c)Aquaporin-2inloopofHenle d)Aquaporin-2inCD CorrectAnswer-CAns.C.Aquaporin-2inloopofHenle[RefGanong24thiep.683-690]AquaporinsareproteinchannelswhichhelpinrapiddiffusionofwaterProximaltublesandthindescendinglimbofloopofHenleaquaporin-1,whichisindependentofADH.Latedistaltubuleandcollectingductaquaporin-2,dependentonADH.
269.Whichofthefollowingexplainsuptakeof 0,infetalcirculation? a)Bohr'seffect b)Halden'seffect c)HigheraffinityofHbFfor0, d)Noneoftheabove CorrectAnswer-CAns.C.HigheraffinityofHbFfor0,[RefSmith'sanaesthesia3rdlep.77]Fetalhemoglobin'sgreateraffinityforoxygenimprovesoxygenuptakeattheplacenta.Agreateraffinityforoxygenisanadvantageforuptakeattheplacenta.
270.Plasmainulinofapersonis4mg/mland urineflowrateis20ml/min.WhatwillbeGFRifurineinulinis50mg/ml? a)125ml/min b)250ml/min c)500ml/min d)1000ml/min CorrectAnswer-BAns.B.250ml/min[RefGanong23rdlep.678,679]GFR?UrineinulinxUrineflowGFR=?250ml/min.
271.Whichofthefollowingexplainsdelivery of02infetalcirculation? a)Bohr'seffect b)Halden'seffect c)HigheraffinityofHbFfor02 d)Noneoftheabove CorrectAnswer-AAns.A.Bohr'seffectUptakeof0,atplacentaDuetohighaffinityofHbFfor02Deliveryof02attissuelevelDuetoBohreffect.
272.Trueof02-Hbdissociationcurve? a)Straightlinecurve b)100%saturatedatP02of100mmHg c)Cooperativebinding d)Hbmoleculecancarry6moleculesof0, CorrectAnswer-CAns.C.CooperativebindingMolecularbasis:"Duetophenomenon"CooperativebindingofOxygentohemoglobin".Stepsinvolved:Hemoglobin,atetramerFourO2moleculesbinds1Hbmolecule.1stO2moleculebondswithgreatestdifficulty.IncreasesaffinitytonextO2molecule.
273.Whichincreasesaffinityofhemoglobin for0,- a)Acidosis b)Hyperthermia c)HighpH d)HighPCO2 CorrectAnswer-CAns.C.HighpHConditionsassociatedwithincreasedaffinityofhemoglobinforoxygen:HighpH.DecreasedH+ionconcentration(alkalosis).ReducedPCO2Reducedbodytemperature.Reduced2,3-bisphosphoglycerate(2,3-BPG)/2,3-diphosphoglycerate(DPG)Fetalhemoglobin.COpoisoning.
274.Incomparisontohemoglobin,effectof myoglobinonBohreffect? a)Increased b)Decreased c)Same d)NoBohreffect CorrectAnswer-DAns.D.NoBohreffect[RefPrinciplesofmedicalphysiologyp.711]Myoglobin:Singlepolypeptidechain.Humanmyoglobincontains152aminoacidswithamolecularweightof17,500.Hemeisattachedto92"dhistidinresidue.Onemoleculeofmyoglobincancombinewithonemoleculeofoxygen.MyoglobinhashigheraffinitytooxygenthanthatofHb.MyoglobinhashighoxygenaffinitywhileBohreffect,cooperativeeffectand2,3-diphosphoglycerateeffectcanabsent.
275.FunctionofchlorideshiftinRBCs? a)RightshiftofHb-O,curve b)LeftshiftofHb-02curve c)TransportofCO2 d)Diffusionof02inalveoli CorrectAnswer-CAns.C.TransportofCO2[RefGanong24th/ep.644;Principlesofmedicalphysiologyp.819]TransportofCO2:*Carbondioxideistransportedinbloodasplasmabicarbonate.*Redbloodcells(RBCs)playamajorroleinthemechanismbecauseRBCscontaintheenzymecarbonicanhydrasethatcatalyzesthereactionCO2+H20=HCO3+H.*HencewhenCO2diffusesintotheRBC,itreactschemicallywithwatertogenerateHCO3.*TheH+ionsaremoppedupbyhemoglobin,whichisanexcellentbuffer.*Thisenablesthereactiontoproceedintheforwarddirection.*TheHCO3-ionsgenerateddiffuseoutintotheplasmainexchangeforClionsthatdiffuseintoRBCssimultaneously.*ThemovementofchlorideionsintoRBCiscalledChlorideshift.-TheaboveeventsresultsinanincreaseintotalnumberionsinsidetheRBC,whichincreasesitsosmolarity.-Asaresult,waterenterstheRBCthroughosmosis.
276.FunctionofLaciscellsinnephron? a)H+secretion b)Na+reabsorption c)Reninsecretion d)Regulationofvasoconstriction/vasodilatationofarterioles CorrectAnswer-DAns.D.Regulationofvasoconstriction/vasodilatationofarterioles[RefPrinciplesofmedicalphysiologyp.412]Juxtaglomerular/Extraglomerularmesangialcells(Laciscells)formingconnectionviaactinandmicrotubuleswhichallowforselectivevasoconstriction/vasodilationoftherenalafferentandefferentarterioleswithmesangialcellcontraction.Note:Laciscellsalsocontainsomerenin.ButReninismainlysecretedbyjuxtaglomerularcells.
277.Closingvolumeisrelatedtowhichofthe following? a)Tidalvolume b)Residualvolume c)Vitalcapacity d)None CorrectAnswer-BAns.B.Residualvolume[RefPrinciplesofmedicalphysiologyp.240,241]Theclosingvolumeisthepointatwhichdynamiccompressionoftheairwaysbegins,especiallyduringforcedexpiration.Lower(dependent)partsofthelungshaslessertransmuralpressure,thereforetheybegintocloseearly.Therefore,closingvolumeisthelungvolumeaboveresidualvolumeatwhichairwayinthelower,dependentpartsofthelungsbegintocloseoff.Closingcapacityisthelungvolume(includingresidualvolume)atwhichairwaysinthelower,dependentpartsofthelungsbegintocloseoff,i.e.,Closingcapacity=closingvolume+residualvolume.Closingcapacityandvolumearetestedforsmallairwayfunction.Criticalclosingvolumeistheminimumvolumeandpressureofgasnecessarytopreventsmallairwaycollapse.Itissomewhatnearresidualvolume.
278.Trueaboutfunctionofdistalconvoluted tubule? a)ReabsorbeNa*byNal(+2c1-channel b)ReabsorbeIC'byNei('channel c)WaterreabsorptionbyADH d)Allarecorrect CorrectAnswer-CAns.C.WaterreabsorptionbyADHOver-allimpactofreabsorptioninearlydistaltubuleistodiluteurinebyremovingsolutes.Latesegmentofdistaltubuleisfunctionallysimilartocorticalcollectingduct.Principal(P)cellsreabsorbsodium&waterfromlumen(ByADH&secretepotassiumintolumen.Intercalated(I)cellsreabsorbpotassium&secretehydrogenintolumen.Cl-isreabsorbedintolatedistaltubule.
279.Reninsecretionisdecreasedby? a)Sympatheticstimulation b)Prostacycline[PGI2] c)Naclindistaltubules d)Hypotension CorrectAnswer-CAns.C.Naclindistaltubules[RefGanong241thlep.674,670]Principalregulatorsofreninsecretion:Thejuxtaglomerularcellsthemselvesarethesensorsoftheafferentarteriolarpressure.LoweredpressurestimulatereninreleaseIncreasedNaC1indistaltubulesissensedbymaculadensaandthesignalistransmittedtoJGcells.ThisresultsindecreasedReninrelease.OppositeoccurswhendecreasedNaC1isdeliveredindistaltubule,i.e.,increasedreninrelease.Adenosineisprobablythemediatorofsignal.TheJGcellsareinnervatedbysympatheticfibers.Theyreleaserenininresponsetosympatheticdischarge,andbycirculatingcatecholamines.Prostacycline(PGI2)stimulatesreninsecretionthroughadirectaction.
280.Mostimportantcerebralvasodilator? a)H+ b)Na+ c)Cal+ d)None CorrectAnswer-AAns.A.H+[RefR.K.Marya3rdiep.156]ThemainmetabolicfactorresponsibleforthevasodilatationassociatedwithcerebralactivityistheCO2producedbytheactivatedneurons.IncreaseinbloodPCO2alsoproducescerebralvasodilatation.ThevasodilatoryeffectofCO2isindirectandismediatedbyformationoflocalH+whichhasadirectvasodilatoryeffectoncerebralbloodvessels.AfallinbloodPO,producescerebralvasodilatationandanincreaseinbloodPO,producescerebralvasoconstriction.
281.Actionpotentialincardiacmusclesis duetowhichions? a)K* b)Na* c)Ca' d)CI? CorrectAnswer-A:B:CAns.b>a&cNa+,K+andCa+,allareinvolvedinfullcycleofactionpotentialincardiacmuscle.But,themainphase(phase0ordepolarization)isduetoNa+ions.Phase0(phaseofrapiddepolarization)openingoffastsodiumchannelswithNa*influx.Phase1(initialphaseofrapidrepolarization)-4closureoffastsodiumchannels.Phase2(plateuphase)openingofvoltagegatedslowCa**channelswithcalciuminflux.Phase3(finalrepolarization)openingofK*channelswithefflux.Phase4-4Restingmembranepotential.
282.Whichofthefollowingcauseincreasein pulmonaryarterialpressure? a)Histamine b)Hypoxia c)ANP d)PGI2 CorrectAnswer-BAns.B.Hypoxia[RefGanong24th/ep.637]Hypoxiacausesvasoconstrictioninpulmonarybloodvesselscausingincreaseinpulmonaryarterialpressure.Effectofvariousstimulationsonpulmonaryvessels:Vasoconstriction:alpha-adrenergicThromboxane-A2AngiotensinIILTC4,LTD4EndothelinsHypoxiaHypercapnia
283.Heartsoundoccuringjustbeforeclosure ofAV? a)S1 b)S2 c)S3 d)S4 CorrectAnswer-DAns.D.S4[RefCECILp.212]S4occursjustbefore1stheartsound(1stheartsoundisduetoclosureofAVvalve,i.e.mitral&tricuspidvalve).
284.EffectofpositiveG? a)Increasedcerebralarterialpressure b)Increasedvenousreturn c)Decreasedcardiacoutput d)Increasedpressureinlowerlimb CorrectAnswer-CAns.C.Decreasedcardiacoutput[RefGanong25thiep.576,24thlep.607-608,Principlesofmedicalphysiologyp.632]EffectsofpositiveG:ThrowingofbloodinthelowerpartIncreasedlowerlimbvenouspressureDecreasedcerebralarterialpressureDecreased,venousreturnDecreased,cardiacoutputGray-outandBlack-out.
285.Centralchemoreceptorsarenot stimulatedby? a)TPCO2 b)TEl'inCSF c)Hypoxia d)Allstimulate CorrectAnswer-CAns.C.Hypoxia[RefGanong25th/ep.658]Centralchemoreceptors:Locatedinachemosensitiveareaontheventralsurfaceofthemedullaneartheexitoftheninthandtenthcranialnerves.Theprimarystimulusforthecentralchemoreceptorsisanincreaseinthehydrogenionconcentration.Stimulationofcentralchemoreceptorsbyincreasedhydrogenionconcentrationleadstoexcitationoftherespiratoryneurons,therebyproducinganincreaseintherateanddepthofrespiration.CentralchemoreceptorsaredirectlystimulatedbyanincreaseinH*concentrationinCSFandbraininerstitialtissue,whichisbroughtaboutbychangeinarterialPCO2(PaCO2).Notstimulatedbyhypoxia;ratherlikeanyothercells,theyaredepressedbyhypoxia.
286.Chemicalregulationofrespirationisnot affectedby? a)P02 b)PCO2 c)pH d)MeanBP CorrectAnswer-DAns.D.MeanBP[RefPrinciplesofmedicalphysiology;Ganong24th/ep.662-663]ChemicalRegulationCentralchemoreceptors:TFPConcentrationinCSF(1,pHofCSF);TPCO,ofblood.Peripheralchemoreceptors:LP02,TPACO2,acidosis(4pH)
287.Trueabouthighaltitudeacclimatization? a)Leftshift0102-Hbcurve b)DecreasedRBCcount c)Hypoventilation d)Increasederythropoietin CorrectAnswer-DAns.D.Increasederythropoietin[RefGanong24th/ep.650,651&23'/ep.617-619;Guyton12ip.529,530]Acclimatization:Importalcompensatorymechanismsathighaltitudeare:-Hyperventilation:-CausesCO2washout,.1.,PCO2andrespiratoryalkalosis.Increased2,3DPG:-Rightwardshiftof02-Hbdissociationcurve.PolycythemiaandincreasedHb:-Duetoincreasederythropoietinreleasewhichcausesabsolutepolycythemiawithincreasedredcellmass.Others:-Increasedrenalexcretionofalkali(HCO3-),increasedtissuevascularity,increasedoxidativemetabolism,Increaseddiffusioncapacityoflung,increasedmyoglobin.
288.Respiratoryexchangeofgasesisstrated from? a)Branchi b)Alveoli c)Bronchiole d)Tissuelevel CorrectAnswer-BAns.B.Alveoli[RefGanong25th/ep.639-640]Externalrespiration:Itconsistsofexchangeofgases(02andCO2)inthealveoli.Thereisdiffusionof02fromalveolarairintopulmonarycapillarybloodanddiffusionofCO2intooppositedirection.
289.Distendingcapacityoflungismaximum at? a)Apex b)Base c)Midregion d)Posteriorlobe CorrectAnswer-AAns.A.Apex[RefUnderstandingsofmedicalphysiologyp.791]"Theairspacesattheapicesofthelungstendtoberelativelydistended,duetoweightofthelungseffectivelydraggingitselfdownwards,puttingtractionontheupperpartofthelungandstretchingtheapicalairspacesopen."
290.Baroreceptorsarerelatedtowhich vessels? a)Internalcarotidartery b)Externalcarotidartery c)Subclavianartery d)Brachiocephalictrunk CorrectAnswer-AAns.A.Internalcarotidartery[RefGanong24thlep.590,591;Principlesofmedicalphysiologyp.791]Baroreceptorsaremechanoreceptorsthatarelocatedintheadventiaofcarotidarteryandaorta,atspecializedlocationscalledsinuses.
291.S2isassociatedwith? a)Rapidventricularfilling b)Atrialcontraction c)Closureofsemilunarvalves d)ClosureofAVvalves CorrectAnswer-CAns.C.ClosureofsemilunarvalvesS2isduetoclosureofsemilunarvalves(aorticandpulmonaryvalves).
292.51S2ischeckedbywhichreflex? a)Kneejerk b)Patellarreflex c)Calcanealreflex d)None CorrectAnswer-CAns.C.CalcanealreflexS1S2ischeckedbyanklejerk(alsocalledCalcanealreflexorachillesreflex).
293.Prostaglandinwasdiscoveredfrom? a)Tear b)Saliva c)Seminalfluid d)Blood CorrectAnswer-CAns.C.SeminalfluidThenameprostaglandincomesfromtheprostategland.Whenprostaglandinwasfirstisolatedfromseminalfluid,itwasbelievedtohavebeenaddedfromtheprostate."
294.Correctformulais? a)GFR=Kfx10 b)Kf=GFRx10 c)Kf=GFRx125 d)GFR=Kfx125 CorrectAnswer-AAns.A.GFR=Kfx10TheGFRisdeterminedby(l)thesumofthehydrostaticandcolloidosmoticforcesacrosstheglomerularmembrane,whichgivesnetfiltrationpressure,and(2)theglomerularcapillaryfiltrationcoefficient(Kr).Mathematically,theGFRequalstheproductofKfandthenetfiltrationpressure.
295.Whichofthefollowingequationis correctregardingequilibriumpotentialfordiffusion? a)EMF=25CA/CB b)EMF=41CA/CB c)EMF=61CA/CB d)EMF=80CA/CB CorrectAnswer-CAns.C.EMF=61CA/CBWhentwoionicsolution(ions)AandBofdifferentconcentration(CaandCb)ofanionseparatedbyapermeablemembrane,theionstendtodiffusealongtheirconcentrationgradient.Sinceionsarechargedparticlestheirdiffusioncanbestoppedbyanappropriateelectricalpotential(E)appliedacrossthemembrane.Themagnitudeandpolarityofthepotential(equilibriumpotential)thatmustbeappliedtosideAofthemembraneforstoppingthediffusionofions(Ea)isgivenbynernstequation,i.e.,theequilibriumpotentialforanioniscalculatedbyNernstequation.
296.Mostimportantfactorintransportacross amembrane? a)Chargeofparticle b)Membranethickness c)Sizeofparticle d)Concentrationgradient CorrectAnswer-DAns.D.Concentrationgradient[RefGuyton12h/ep.48-501]Transportacrossacellmembraneisdividedintopassiveoractive,basedonwhetheritisalongtheconcentrationgradientoragainsttheconcentrationgradient.1)PassivetransportItisinthedirectionofconcentrationgradienti.e.,"Downhillmovement".2)ActivetransportItisagainstthedirectionofconcentrationgradient,i.e.,"Uphillmovement".
297.Tronsportprocesswhichisagainst concentrationgradientandcarriermediatedis? a)Facilitateddiffusion b)Osmosis c)Activetransport d)Endocytosis CorrectAnswer-CAns.C.ActivetransportActivetransport:Itisagainstthedirectionofconcentrationgradient,i.e.,*Uphill6ovenento.Energy(e.g.,ATP)isrequiredCarrierproteinisrequiredExamplesareprimaryactivetransportandsecondaryactivetransport.
298.Similaritybetweenactivetransportand facilitateddiffusion? a)Energyrequirment b)Againstconcentrationgradient c)Carrierprotein d)Alloftheabove CorrectAnswer-CAns.C.Carrierprotein1)PassivetransportDirectionofconcentrationgradienti.e.,'Downhillmovement"DoesnotrequireenergyexpenditureExampleare:- 1. Withoutcarriers:-Simplediffirsion,osmosis2. Throughcarrier:-Facilitateddiftrsion 2)ActivetransportItisagainstthedirectionofconcentrationgradient,i.e.,*Uphill6ovenento.Energy(e.g.,ATP)isrequiredCarrierproteinrequiredExamplesareprimaryactivetransportandsecondaryactivetransport.
299.Transportthroughporesincellmembers is? a)Activetranspert b)Transcytosis c)Diffusion d)Endocytosis CorrectAnswer-CAns.C.Diffusion[Ref:Guytonp.49]Substancescanmovebysimplediffusiondirectlyalongtheporesandchannelsfromonesideofthemembranetotheother.Thus,simplediffusioncanoccurbytwopathways. 1. Throughmembranelipidbilayerforlipidsolublesubstances.2. Throughpores(waterchannel)-+forions/electrolytes.
300. Percentageoftotalbodywatertobody weightatbirth? a)90% b)80% c)60% d)50% CorrectAnswer-BAns.B.80%[RefPrinciplesofmedicalphysiologyp.712]Themajorcomponentofbodymassiswater.Thecontributionofwatertobodyweightvarieswithage.Totalbodywater(TBW)asapercentageofbodyweightdeclinesformashighas90%inearlyfetallifeto75-80%atbirth.Thereafteritdelinesprogressivelyto60%bytheendofoneyear.Afterthatitremainsconstant.
301.Epithelialsodiumchannelshas? a)2a,213 b)la,i(3 c)2a,213,2y d)2a,113,2y CorrectAnswer-DAns.D.2a,113,2y[Ref:Principlesofmedicalphysiologyp.241]TherearetwodifferenttypesofSodiumchannels:-Voltage-gatedsodiumchannels:ThesearepresentinExcitablecells.Theseexistasheterodimerorheterotrimersofalphaandbetasubunits,containingonealphaandoneortwobetasubunits.Epithelial-sodiumchannels:Thesearepresentinepitheliumofabsorptiveorsecretoryepithelium,e.g.colon,sweatglandduct,pancreaticduct,respiratorypassage,anddistaltubuleofkidney.Theseexistasheterotetramersofalpha,betaandgammasubunits,containingmostlytwoalpha,onebetaandonegammasubunits.
302.TrueaboutENaCareallexcept? a)Epithelialchannel b)Composedof2homoloussubunits c)PresentinkidneyandGIT d)Inhibitedbyamiloride CorrectAnswer-BAns.B.Composedof2homoloussubunitsEpithelialNa+channels(ENaC)isratelimitingstepinNa+reabsorptionacrossseveralepitheliallinings.Itispresentinkidney(distalpart),GIT(colon),salivary&sweatglands,andrespiratorytract.ENaCismadeofthreehomologoussubunits>alpha,beta,andgamma.Inlatedistaltubulesandcollectingducts,ENaCisinhibitedbypotassiumsparingdiureticslikeamilorideandtriameterene.
303.pHofintracellularfluidis? a)SlightlylessthanECF b)SlightlymorethanECF c)SameasECF d)Highlyalkaline CorrectAnswer-AAns.A.SlightlylessthanECF[Ref:Principlesofmedicalphysiologyp.132]Extracellularfluid(ECF)haspH7.4(range7.35-7.45)andisslightlyalkalineIntracellularfluid(ICF)hasH*ionconcentrationslightlyhigherthanECF.Thus,pHofICFisslightlylowthanECF,butstillitisslightlyalkaline.
304.Increasedinplasmaviscosityis maximallycausedbywhichplasmaprotein? a)Fibrinogen b)Albumin c)Globulin d)Allhaveequaleffect CorrectAnswer-CAns.C.Globulin[Ref:Clinicalaspectsofbloodp.80]Theeffectofaproteinonplasmaviscositydependsonitsmolecularweightandstructure.Theviscosityishigherifaproteinhas 1. Lessspheroidshape2. Highermolecularweight3. Higheraggregationcapacity4. HighertemperatureorpHsensitivity Theglobulincausesmaximumincreaseinplasmaviscosityfollowedbyfibrinogen(2dafterglobnlin)andalbumin(3rdinnumber).
305.Oncoticpressureiscontributedby? a)Sodium b)Chloride c)Chloride d)Albumin CorrectAnswer-DAns.D.Albumin[Ref:Clinicalphysiology3'd/ep.336]Oncoticpressure,alsocalledcolloidosmoticpressure,isaformofosmoticpressureexertedbyproteinsinbloodplasmathatusuallytendstopullthewaterintothecirculatorysystem.Themajorcontributingproteinforplasmaoncoticpressureisalbumin.
306.Mostrecenttastesensationis? a)Sweet b)Sour c)Bitter d)Umami CorrectAnswer-DAns.D.UmamiTheumamitasteisthefifthtastewhichisunique.Theproposedmechanismofumamitasteisthroughglutamatetastesensors(glutamatereceptors)withreleaseofneuronalglutamicacid.Innature,therearethreeumamisubstances:Monosodiumglutamate(MSG)Disodium5-guanosinemosphosphate(GMP)Disodium5-ionsinemonophosphate(lMP)
307.Motorevokedpotentialassess? a)Peripheralmotorpathways b)Centralmotorpathways c)Bothoftheabove d)Regenerationinmuscles CorrectAnswer-BAns.B.CentralmotorpathwaysMotorevokedpotentials(MEPs)areelectricalsignalsrecordedfromneuraltissueormusclefollowingactivationofcentralmotorpathways.Itisusedforassessmentofnervoussystem,especiallyduringintraoperativeneurophysiologicalmonitoring(IONM).Mostoften,thisisaccomplishedbyusingtranscranialelectricalstimulation(TES)ofbrainandrecordingofevokedneuralormyogenicactivitydistal(caudal)toareathatisatriskduringsurgery.
308.Firsttooccurafterasharpnervecut? a)Chromatolysis b)Polymorphicarrangement c)Increasedproteinsynthesis d)Macrophageactivation CorrectAnswer-AAns.A.ChromatolysisWithin6hoursofinjury,thenucleusmigratestotheperipheryofthecellwhereNissl'sgranulesandroughendoplasmicreticulumbreakupanddisperse.Thisphenomenoniscalledchromatolysis.Thepartofnervedistaltothepointinjuryundergoes'secondaryorWalleriandegeneration',theproximalpartundergoes"primaryorretrograde"degenerationuptoasinglenodeRanvier.
309.Whichofthefollowingisfalseabout peripheralnerveinjury? a)Neuropraxiaisirreversible b)Epineuriumisintactinaxonotmesis c)Neurotmesisisthemostsevereformofinjury d)Welleriangenerationstartsinaxonotmesis CorrectAnswer-AAns.A.NeuropraxiaisirreversibleNeuropraxia(Classl)Thisistheleastsevereformofnerveinjury,withcompleterecovery.Inthiscase,theaxonremainsintact,butthereismyelindamagecausinganinterruptioninconductionoftheimpulsedownthenervefiber.Mostcommonly,thisinvolvescompressionofthenerveordisruptiontothebloodsupply(ischemia).NoWalleriandegenerationisseen.
310.Bloodtestisbarrierintestisisformed by? a)Sertolicells b)Leydigcells c)Granulosacells d)None CorrectAnswer-AAns.A.Sertolicells[RefGanong23'd/ep.402]Junctionbetweenadjacentsertolicellsformblood-testisbarrier.
311.Inelectromyograply[EMG]transient responseatthetimeofinsertionofeloctrodeindicates? a)Spontoneousmuscleactivity b)Voluntarymuscleactivity c)Inducedmuscleactivity d)Cellmembranedamage CorrectAnswer-DAns.D.Cellmembranedamage[Ref:Clinicalphysiology24th/ep.222]Electromyographyisaprocessofrecordingelectricalactivityofmuscles.Itcanbedonebyeitherofthetwomethods: 1. Byputtingasurfaceelectrodeandrecordingactivityofunderlying muscle. 2. Byinsertinganeedleelectrodeintothemuscle. Therearetheretypesofsignals(byneedleelectrode):-i)Insertionalactivity:Itistheelectricalactivityatthetimeofinsertionofelectrodeduetodisruptionofcellmembrane.Thisshouldbeignored.ii)Restingactivity(spontaneousactivity).iii)Voluntarymusclerecruitment.
312.Caisson'sdiseaseisassociatedwith? a)Rapiddescendinaircraft b)Rapiddescendofdeepseadivers c)Underwaterconstructionworkers d)Alloftheabove CorrectAnswer-CAns.C.UnderwaterconstructionworkersCaisson'sdisease,(alsocalleddecompressionsickness,Bends,Diver'sParalysis,Dysbarism)isaparticularformofgasembolism,whichoccurswhenindividualsareexposedtosuddenloweringofatmosphericpressurelike-rapidascendofscubaanddeepseadivers,individualinunpressurizedaircraftinrapidascent(e.g.,inpilots),underwaterconstructionworkersandextra-vehicularactivityfromspacecraft.
313.Trueaboutvisualcyclecascade? a)Associatedwithconformationalchangeinopsin b)Lightcausesisomerizationofall-trans-retinolto11Cis-retinol c)Retinol[alcohol]isinvolved d)Allaretrue CorrectAnswer-AAns.A.AssociatedwithconformationalchangeinopsinThereisconformationalchangeinopsin.Lightcausesconversionof11cis-retinaltoalltransretinal.Retinal(aldehyde)isinvolved(notretinal).Whenlightfansonphotoreceptors,11-Cisretinalofrhodopsinisisomerizedtoall-transretinal(Photoisomerization).Thechangeinphysicalconfigurationissuchthatitcannotholdproteinopsinandthereforetwoareseparated,i.e.rhodopsinishydrolyzed.
314.Trueaboutsmoothmusclecontraction? a)Troponinplaysanimportantrole b)Calmodulinhasnorole c)Phosphorylationofmyosin d)Alloftheabove CorrectAnswer-CAns.C.Phosphorylationofmyosin[RefGuyton12'h/ep.64-66]Insmoothmusclethereisnotroponin.Thereforecalciuminitiatescontractionthroughamechanismdifferentfromthatemployedbyskeletalmuscle.Smoothmusclecontainsacalciumbindingproteincalledcalmodulin.Increaseincytoplasmic(sarcoplasmic)calciumleadstoitsbindingtocalmodulin.Thecalcium-calmodulincomplexactivatesmyosinkinase,alsocalledmyosinlightchainkinase(MLCK).MLCKisaphosphorylasewhichphosphorylatesalightchainbelongingtomyosinchain,oftencalledcross-bridgephosphorylation.Thephosphorylatedmyosinheadinteractwithactin,i.e.,cross-bridgingofmyosinwithactin.Thecross-bridgingleadstocontraction.
315.IncreaseinDurationofexpirationisdue to? a)J-reflex b)Head'sparadoxicalreflex c)Hering-Breurereflex d)Proprioceptors CorrectAnswer-CAns.C.Hering-Breurereflex[RefGanong24h/ep.664623d/ep.632]TheHerring-Breuerinflationreflexisanincreaseinthedurationofexpirationproducedbysteadylunginflation,andtheHerring-Breuerdeflationreflexisadecreaseinthedurationofexpirationproducedbymarkeddeflationofthelung.
316.IfHbAlCis8%,Whatwillbethevalueof bloodglucose[mg/d1]? a)100 b)150 c)200 d)300 CorrectAnswer-CAns.C.200Meanbloodglucose(mg/dl)=(35.6xHbA1C)-77.3=(35.6x8)-77.3=207.5Meanbloodglucose(mmoUL)=(1.98xHbA1C)-4.29
317.RespirateryquotientistheRatioof- a)CO2consumedto02released b)02releasedtoCO2consumed c)Co,releasedto02consumed d)02consumedtoCo,released CorrectAnswer-CAns.C.Co,releasedto02consumedRQistheratiooftheamountofCO2releasedtotheamountofO2consumed.RQofCarbohydrateis1.00,forfatis0.70andforproteinsitisabout0.82.
318.Walleriandegenerationisfor? a)Nervedegeneration b)Muscledegeneration c)Nerveregeneration d)Muscleregeneration CorrectAnswer-AAns.A.Nervedegeneration[Ref:SamsonWright13h/ep.288]Thepartofnervedistaltothepointinjuryundergoes'secondaryorWalleriandegeneration',theproximalpartundergoes"primaryorretrograde"degenerationuptoasinglenodeRanvier.
319.Sizeofplateletsis? a)1A? b)2A? c)1?m d)2?m CorrectAnswer-DAns.D.2?mPlatelet=2-3micrometer.
320.Glucagonactivateswhichenzyme? a)Pepsinogen b)Trypsinogen c)Adenylylcyclase d)None CorrectAnswer-CAns.C.AdenylylcyclaseGlucagonactsthroughcAMPbyactivatingadenylylcyclase.
321.InhibitionofheartbyvagusbyM2 receptorsismedicatedbywhichmechanism? a)cAMP b)Cat' c)DAG d)None CorrectAnswer-AAns.A.cAMPMuscarinicreceptors(cholinergicreceptors)inheartareM2type.Theseareresponsibleforvagusmediatedbradycardia.M2mediatedactionsarethroughcAMP
322.Inhibitionofheartbyvagusismediated bywhichreceptors- a)M1 b)M2 c)NN d)NM2 CorrectAnswer-BAns.B.M2EffectofparasympatheticsystemonheartarethroughM2receptors.
323.Penileerectionismediatedby? a)Parasympatheticsystemviamuscarinicreceptors b)Parasympatheticsystemvianicotinicreceptors c)Sympatheticsystemviaa-receptors d)Sympatheticsystemvia(3-receptors CorrectAnswer-AAns.A.Parasympatheticsystemviamuscarinicreceptors[RefGanong24'h/ep.339-342,Ganong23d/ep.341]ErectionofpenisMuscariniceffectofparasympatheticsystem.Ejaculation-alpha-receptorofsympatheticsystem
324.Withdrawalreflexisalsoknownas? a)Extensionreflex b)Stretchreflex c)Golgitendonreflex d)Flexorreflex CorrectAnswer-DAns.D.Flexorreflex[RefUnderstandingofmedicalphysiologyp.680]Withdrawalreflexisatypicalprotectivereflex.Apainfulstimulusappliedtothehandorfootresultsinwithdrawalofthelimb.Withdrawalinvolvesflexionofthelimbthereforeitisalsocalledasflexionreflex.Flexionresultsfromcontractionofflexormusclesandrelaxationofextensormuscles.Simultaneouscontractionofflexorsandrelaxationofextensorsisbroughtaboutbyreciprocalinnervation.
325.Tetanyinmuscleoccursinspiteof normalserumCa"level.Whichionisresponsible? a)Mg2+ b)Ca2+ c)K+ d)Na+ CorrectAnswer-BAns.B.Ca2+[Ref:Principlesofmedialphysiologyp.105,1061]Duringasingletwitch,theamountofCa+2releasedintosarcoplasmisnotenoughtoproducetetanictension.Whenthemuscleisstimulatedinrapidsuccession,Ca+2comesoutintothesarcoplasmwitheachstimulusandthereisaprogressiveaccumulationofCa2+inthesarcoplasm.TetanictensionisreachedwhensarcoplasmicCa2+levelsreachtheirmaximum.
326.Unspecifiedpainpathwayisfor? a)Neuropathicpain b)Trauma c)Visceralpain d)Psychogenicpain CorrectAnswer-DAns.D.PsychogenicpainTextbookofpsychotherapyp.6Idiopathicorunspecifiedpain:Itispurelypsychologicalinnatureandisthereforecalledpsychogenicpain.
327.Painiscarriedbywhichnervefibers? a)Act,A13 b)Act,Ay c)AS,C d)Ay,C CorrectAnswer-A:CAns.A.Act,A13&C.AS,C[RdGanong24n/ep.92&23'd/ep.89;Principlesofphysiologyp.5121]Fastfiberscarryingpain-+Ad(fastpain)Slowfiberscarryingpain-)C(slowpain)
328.Actionpotentialgeneratesatfastestrate in? a)SAnode b)AVnode c)BondleofHis d)Purkinjefibers CorrectAnswer-AAns.A.SAnode[Ref:Essentialsofmedicalphysiologp.856]SAnodedischargesimpulsesatfastestrate,hencetherateatwhichSAnodefiresdeterminestheheartrate,therefore,SAnodeisnormalpacemakeroftheheart,i.e.,itdeterminesthepaceoftheheart.
329.Vibrationsenseisdetectedbywhich typeofreceptor? a)Merkel'sdisc b)Ruffini'sendorgan c)Pacciniancorpuscle d)Meissner'scorpuscle CorrectAnswer-CAns.C.Pacciniancorpuscle[RefPrinciplesofmedicalphysiologyp.647]Tactile(touch)receptorsFortouch(superficialtouch):-Meissner'scorpuscle(detecttextureofsurface,i.e.roughorsmooth),Merkel'sdisc(detecttwopointdiscrimination).Forpressure(deeptouch):-Rufini'sendorgan(slowlyadapting).Vibrations:DetectedbyPaciniancorpuscle(rapidlyadapting).
330.Vibrationsenseisdetectedby? a)Nociceptors b)Deepreceptors c)Superficialreceptors d)Noneoftheabove CorrectAnswer-DAns.D.Noneoftheabove[Refprinciplesofmedicalphysiologyp.647]VibrationsaredetectedbyPaciniancorpuscleswhicharedeeptactilereceptors.Tactile(touch)receptorsSuperficial(inepidermisandpapillarylayerofdermis)>Merkel'sdisc,meissner'scorpuscle.Deep(indermisandsubcutaneoustissue)-+Ruffini'sendorgan,Paciniancorpuscle.
331.Vibrationsaredetectedbywhichtypes ofreceptors? a)Slowlyadapting b)Rapidlyadapting c)Non-adapting d)Noneoftheabove CorrectAnswer-BAns.B.RapidlyadaptingRapidlyadaptingtouchreceptors-Paciniancorpwcle,Meissner'scorpuscle.Slowlyadaptingtouchreceptors-Merkel'sdisc,Ruffini'sendorgan.Noadaptation-Nociceptors(Painreceptors),vestibularreceptors,musclespindle.
332.Whichofthefollowingreceptoris stimulatedbysustainedpressure? a)Ruffini'sendorgan b)Merkel'sdisc c)Haircells d)MeissnerCorpuscles CorrectAnswer-AAns.A.Ruffini'sendorgan[Ref;Ganong23r/ep.I50]Pressure(sustainedpressure)stimulatesRuffini'sendorgan,
333.Mostimportantintracellularbuffer? a)Bicarbonate b)Albumin c)Phosphate d)Ammonia CorrectAnswer-CAns.C.PhosphateBloodbuffers:Hemoglobin,Plasmaproteins,Bicarbonate.Intracellularbuffers:Phosphates(H2PO4),intracellularproteins.Urinarybuffers-Bicarbonate,Phosphate,ammonia.
334.Ironisconservedby? a)Hemopexin b)Hepicidin c)Hemomedins d)None CorrectAnswer-AAns.A.Hemopexin[Ref:Vasudevan3n/ep.196]Humanbodyhasmechanismstoconserveironandpreventitslossfrombody-i)WhenRBCislysed,hemoglobinentersintocirculation.Beingsmallmolecularweightsubstancehemoglobinwillbelostthroughurine.Topreventthisloss,Hbisimmediatelytakenupbyhaptoglobin.ii)WhentheglobinpartisremovedfromHb,thehemeisproduced,andisreleaseditocirculation.Inordertopreventitsexcretionthroughurine,hemeisboundwithhemopexin.
335.Acrosomereactionisseenin? a)Spermatogenesis b)Oogenesis c)Fertilization d)Mensturation CorrectAnswer-CAns.C.FertilizationTofertilizetheovumthespermsundergo- 1. Capacitation2. Acrosomereaction Acrosomereaction:Itfollowsthecapacitationofthesperm.Itoccursinampulla.Spermbindstozonapellucida?Zonaprotein-3(ZP-3)ofzonapellucidahelpsinattachmentaswellasininducingacrosomalreaction.Acrosomereleaseslysomalenzymes,especiallyproacrosinwhichhashighaffinityforzonapellucida.Proacrosinhashydrolyticactionthatdegradeszonapellucidaintheverylocalregionwherethespermcellisattached.Thisallowsspermatozoatoswimtheirwaytothevitellinemembraneoftheovum.Afterthisfertilizationtakesplace.
336.Notacontentofsperm? a)Golgiapparatus b)Mitochondria c)Lysosome d)Endoplasmicreticulum CorrectAnswer-DAns.D.EndoplasmicreticulumSpermatozoan(sperm)hasfollowingparts: 1. Head2. Middlepiece3. Principalpiece4. Endpiece(tail)
337.Broadman'sareaformotorspeech? a)Area1,2,3 b)Area4,6 c)Area28,29 d)Area44 CorrectAnswer-DAns.D.Area44[RefFuller's4lep.10;Ganong24nlep.293]MotorspeechisformedinBroca'sarea(area44).Striateareaofcortexisprimaryvisualarea(Brodmann'sarea17orVI)andislocatedonthesidesofcalcarinefissure.
338.Insulinmediatedtransportofglucoseis ? a)Seeninadiposetissue b)ViaGLUT-2 c)MainMechanisminRBCs d)Allaretrue CorrectAnswer-AAns.A.SeeninadiposetissueInsulinstimulatestheuptakeofglucosebymyocytes(skeletalmuscle,cardiacmuscles),adipocytes(adiposetissue)andhepatocytes.Tissuesthatdonotdependoninsulinforglucoseuptakeincludebrain,erythrocytes(RBC),theepithelialcellsofkidney&intestine,Liver,andCornea&lensofeye.Themechanismthroughwhichinsulinincreasesglucoseuptakeisdifferentindifferenttissues.Inthemuscleandadiposetissues,insulinincreasefacilitateddiffusionbyincreasingglucosetransporter(GLUT-4)onthecellmembrane.
339.Relationshipbetweeninsulinand glucoseconcentration? a)Linear b)Hyperbola c)Sigmoidal d)BellShaped CorrectAnswer-CAns.C.Sigmoidal'TheRelationshipbetweenglucoseconcentrationandinsulinsecretionissigmoidal.Theglucose-insulinresponsecurvecomefromthediscoverythatinsulinsecretiondidnotrespondasalinearfunctionofglucoseconcentration.
340.Maximumdensityofmusclespindleis foundin? a)Calfmuscle b)Lumbricals c)Quadriepsmuscle d)Triceps CorrectAnswer-BAns.B.Lumbricals[Ref-Essentialsofmedicalphysiologyp.786]Themorerefinedthefunction,thegreatertheconcentrationofmusclespindles.Thegreatestconcentrationofspindlesisfoundinthelumbricalmusclesofthehandandtheninthesuboccipitalmusclesandintheextraocularmuscles.
341.3-subumitofinsulinreceptorbindsto? a)Guanylylcyclase b)Adenylylcyclase c)IP3-DAG d)Tyrosinekinase CorrectAnswer-DAns.D.TyrosinekinaseInsulinreceptorsTheinsulinreceptorisacombinationof4subunitsheldtogetherbydisulfidelinkages-TwoAlphasubunitsandtwoBetasubunits,Alphasubunitslieentirelyoutsidethecellmembraneandfunctionasinsulinbindingsite.BetasubunitsPenetratethroughcellmembraneandprotrudeintothecytoplasmwhichhasattachedlocaltyrosinekinase.Thusinsulinreceptorisanexampleofanenzyme-linkedreceptor(insulinkagroupIIDhormone).
342.Functionofepinephirineand norepinephineinFightor-Flightresponseis? a)Increasedbloodflowtoskin b)Increasedbloodflowtomuscles c)Bronchoconstriction d)Bradycardia CorrectAnswer-BAns.B.Increasedbloodflowtomuscles[Ref,Understandingmedicalphysiologyp.470,471]Bothepinephrineandnorepinephrine,alongwithcortisol,areresponsibleforcoordinatingthe"Fight-or-flight"responseinsituationsofperceiveddangerorstress.
343.Ionotropiceffectofthyroidhormoneis by? a)Membranereceptors b)cAMP c)PotentiationofCatecholamines d)cGMP CorrectAnswer-CAns.C.PotentiationofCatecholamines[RelGanong24th/ep.j49lThethyroidhormonesincreasetheheartrate,cardiaccontractility,strokevolumeandcardiacoutput,andconsequentlyalsothesystolicBP.ButthediastolicBPmayfallduetovasodilatationinseveralvascularbedswithdecreaseinperipheralvascularresistance.Thecardiovasculareffectsofthyroidhormonesarepartlymediatedbypotentiationofeffectsofcatecholamines.
344.Hormoneresponsibleforgalactopoiesis ? a)Growthhormone b)Insulin c)Oxytocin d)Prolactin CorrectAnswer-DAns.D.ProlactinGalactokinesisAlsocalledmilkejectionormilkletdovn.Itisbroughtaboutbyoxytocinwhichstimulatescontractionofthemyoepithelialcellsinthemammaryalveoliandductsie.contractionoflactiferousductsandsinuses.Oxytocinsreleasedwhenthenippleisstimulatedduringsuckling.
345.Allareaboutadiponectinexcept? a)Secretedbyadiposetissue b)Lowersglucose c)IncreasesFFAoxidation d)PositiveCorrelationwithBMI CorrectAnswer-DAns.D.PositiveCorrelationwithBMIAdiponectionisahormonesecretedbyadiposetissue.ItlowersglucoseandFFAlevels.AdiponectinhasnegativecorrelationwithBMI,andmorenegativelywithvisceralfatthansubcutaneousfat.Adiponectinhasinszlirsensitizingactionanditslevelscorrelatewithinsulinsensitivity.Byinsulinsensitizingaction,adiponectinreducestissueTGcontent,increaseFFAoxidation,andincreaseglucoseuptakebytissue.Adiponectinalsoinhibitsadhesionmolecules(E-selectin,VEAM)andmacrophages(decreaseuptakeofoxidizedLDL).Adiponectinreceptorsarefoundinliverandskeletalmuscles.Recently,receptorsarealsofoundinpancreasp-cells.Adiponectinsecretionishormoneregulated.Decreasedlevelswithinsulinandglucorticoidsareseen.Adiponectionlevelsarelowinobesity,type2DM,ischemicheartdisease(IHD)anitmetabolicsyndrome.Adiponectingeneislocatedonchromosome3.
346.Somatomedin-Cdeficiencycauses? a)Achondroplasia b)Cretinism c)Growthretardation d)JuvenileDM CorrectAnswer-CAn.s.C.GrowthretardationEffectsofgrowthhormoneonskeletalgrowthismediatedbysomatomedins.Deficiencyofsomatomedinscausesgrowthretardationanddwarfism.
347.Howisfolicacidabsorbedinproximal jejunum? a)Facilitateddiffusion b)Activetransport c)Passivetransport d)Bothactive&passivetransport CorrectAnswer-DAnsD.Bothactive&passivetransportFolatesarePresentinnaturalfoodsandtissuesaspolyglutamatesbecausetheseformsservetokeepthefolateswithincell.Inplasmaandurine,theyarefoundasmonoglutamatesbecausethisistheonlyformthatcanbetransportedacrossmembranes.Enzymesinthelumenofthesmallintestineconvertthepolyglutamateformtothemonoglutamateformofthefolate,whichisabsorbedintheproximaljejunumviabothactiveandpassivetransport.
348.EPSPisdueto? a)K'influx b)Na*efflux c)Na*influx d)Ca**influx CorrectAnswer-CAns.C.Na*influxEPSP-OpeningofligandgatedNa+channelresultinginNa+influx.IPSP-OpeningofligandgatedCl-channelresultinginCl-influx.OpeningofligandgatedK+channelresultinginK+influx
349.VitaminDabsorptionisdecreasedby? a)Proteins b)Acid c)Lactose d)Fatmalabsorption CorrectAnswer-DAns.D.FatmalabsorptionAbsorptionofallfatsolublevitaminsisdecreasedinfatmalabsorption.ThesefatsolublevitaminsareA,D,EandK.
350.Calciumabsorptionishamperedby a)Protein b)Lactose c)Acid d)Phytates CorrectAnswer-DAns.D.PhytatesCalciumabsorptionisincreasedbyi)Lactose,ii)Proteins,andiii)AcidicenvironmentCalciumabsorptionisdecreasedbyi)Phytates,ii)Phosphates,iii)Oxalates;iv)Tetracycline;v)alkalineenvironment
351.Absorptionofcalciumionisaffected mostlyby? a)Calcitriol b)Parathormone c)Glucocorticoids d)ACTH CorrectAnswer-AAns.A.CalcitriolWithanaverageintakeof1000mgofcalciumitsnetintestinalabsorptionisonly150-250mg/day.Calciumisabsorbedmainlyintheduodenumandjejunum(proximalintestine)byanactivetransportmechanismregulatedbycalcitriol.Parathormoneindirectlypromotesabsorptionofcalciumbyincreasingtherenalsynthesisofcalcitriol.
352.Secretionofbileoutofhepactocytes occursvia? a)Passivediffusion b)Facilitateddiffusion c)Osmosis d)Activetransport CorrectAnswer-DAns.D.ActivetransportBilecontainssubstancesthatareactivelysecretedintoitcrossthecanalicularmembrane,suchasbileacids'phosphatidylcholine,conjugatedbilirubin,cholesterol,andxenobiotics.EachoftheseentersthebilebymeansofaspecificcanaliculartransPorter.Itistheactivesecretionofbileacids,however,thatisbelievedtobetheprimarydrivingforcefortheinitialformationofcanalicularbile.
353.SuppressorStriponanterioredgeofpre- centralgyrushasfollowingfunction? a)Increaseextensortone b)Painperception c)Inhibitionofstretchreflex d)Voluntarymovement CorrectAnswer-CAns.C.Inhibitionofstretchreflex[RefGanong25th/ep.242]"Stimulationoftheanterioredgeofprecentralgyruscausesinhibitionofstretchreflex.
354.Exampleofexopeptidaseis? a)Trypsin b)Chymotrypsin c)Elastase d)Carboxypeptidases CorrectAnswer-DAns.D.Carboxypeptidases
355.Doll'seyereflexisusedin? a)Hemiplegic b)Paraplegic c)Unconsciouspatient d)Cerebralpalsy CorrectAnswer-CAns.C.UnconsciouspatientDoll'seyereflex,alsocalledOculocephalicreflex,isusedtoassessbrainfunctioninunconscious/Comatosepatients.Itchecksthevestibule-ocularreflexinunconsciouspatients.Headisrotatedfromsidetosidewitheyeskeptopen.i)Positive(normal)-Eyesmoveinthedirectionoppositetothatoftheheadmovement.Itsignifiesintactbrainstem.ii)Negative(abnormal)-Eyesmoveinthedirectionofheadmovement.Itsignifiesbrainstemdamage.
356.Functionofmyentericplexusisto regulate? a)GIsecretion b)Localbloodflow c)Motility d)Alloftheabove CorrectAnswer-CAns.C.MotilityMyentericplexus(Aurbach'splexus)controlsGImotility.Meissner's(submucosal)plexuscontrolsGIsecretionsandlocalbloodflow.
357.InnerplexusinGITis? a)Mucosalplexus b)Submucosalplexus c)Auerbach'splexus d)Myentericplexus CorrectAnswer-BAns.B.SubmucosalplexusMyentericplexus(Auerbach'splexus)-Externalplexus.Meissner'splexus(submucosalplexus)-Innerplexus.
358.Receptiveareaofstomach? a)Antrum b)Pylorus c)Body d)Fundus CorrectAnswer-DAns.D.FundusAnatomicallythestomachisdividedintofundus,body(corpus),antrumandpylorus.However,functionally,thestomachisdividedintoaproximalanddistalend.'Proximalstomach'includesfundusandproximall/3dofthebodyand'distalstomach"includesdistal2/3dofthebodyandtheantrum.Avasovagalreflextriggeredbyswallowingabolusoffoodcausestheloweresophagealsphinctertoopenandtheproximalstomachtodilate(receptiverelaxation)toaccommodatetheswallowedfood.Asaresult,theinternalpressurehardlyrisesinspiteoftheincreasedfilling.Thus,theproximalstomachservesprimarilythefunctionofstorage.
359.
Partofsympatheticsystemwhichsecretechemicaltransmitter? a)Cardiacganglion b)Cervicalsympatheticchain c)Adrenalmedulla d)Thoracicsympatheticchain CorrectAnswer-CAns.C.Adrenalmedulla[Ref:TextbookofHumanphysiologybysherwoodp.681.]TheAdrenalmedullaisactuallyamodifiedpartofthesympatheticnervoussystem.Theadrenalmedullaconsistsofmodifiedpostganglionicsympatheticneuronscalledchromaffincells.Unlikeordinarypostganglionicsympatheticneurons,chromaffinecells,donothaveaxonalfibersthatterminateoneffectororgans.Instead,onstimulationbypreganglionicfibers,thechromaffineincellsreleasetheirchemicaltransmitterdirectlyintotheblood.
360.IncreasedaldosteroneandADH secretiomfollowingmajortraumaresultsinallthefollowingexcept? a)DecreasedNa+excretionisurine b)IncreasedK'excretioninurine c)Increasedosmolarityofurine d)Increasedwaterexcretion CorrectAnswer-DAns.D.IncreasedwaterexcretionAftermajortrauma,secretionofADHandaldosteroneincreases.ADH-Causesincreasedwaterreabsorptionfromcollectingduct.Aldosterone-CausesincreaseNa+&Cl-reabsorptionandincreaseK+secretion/excretion.
361.NormalUninarypHis? a)5.0-6.0 b)6.5-7.0 c)8.5-9.0 d)None CorrectAnswer-BAns.B.6.5-7.0BloodpH?7.4InterstitialfluidpH?7.34UrinepH?6.5?7.0(4.5to8.0)
362.Whichofthefollowinghasdirect innervationfromsympatheticsystembutnoparasymputheticsupply? a)Heart b)Intestine c)Skin d)None CorrectAnswer-CAns.C.SkinSkinhasnoparasympatheticsupplybuthas:-Sympatheticcholinergicsupply-sweatglandSympatheticadrenergicsupply-cutaneousbloodvessels.
363.ASubstancehasclearancesameas inulinclearance,theSubstarceismainlyexcretedinurineby? a)TubularSecretion b)Glomerularfiltration c)Botha&b d)Vascularleakage CorrectAnswer-BAns.B.GlomerularfiltrationIftherebeasubstancethatpassesfreelyacrosstheglomerularmembranebutisneitherreabsorbednorsecretedbytubularactivity,urinaryexcretionwouldrepresenttheamountfilteredandnothingbuttheamountfiltered.Hence,itsclearancewouldindicatehowmuchplasmagetsfilteredeveryminute.Allthesefeaturesmakeitaverysuitablesubstanceforestimationofglomerularfiltrationrate.InulinclearanceisequaltotheGFR,i.e.,126ml/min.
364.Neuropraxiais? a)Damagetoaxon b)Damagetoendoneurium c)Damagetoepineurium d)NoStructuraldamage CorrectAnswer-DAns.D.NoStructuraldamage[Ref:Apley's8'h/ep'231.]Neuropraxia?Noanatomicaldisruption;axon&myelinsheathremainintact.Axontemesis-Disruptionofaxonwithmyelinsheath;Endoneuriumisintact.Nuerotoemesis-Completesectionofnerve;Axon,myelinsheath,endometrium,perimeurium,epineuriumallaredisrupted.
365.Mechamismofsecretionofammoniain distaltubuleis? a)Primaryactivetransport b)Symport c)Antiport d)Passivediffusion CorrectAnswer-DAns.D.PassivediffusionAmmonia(NH3)transportinvolvespassivediffusionfromtubularcellsintothetubularlumen.
366.RMPinsmoothmuscles? a)-90mV b)-70mV c)-150mV d)-40mV CorrectAnswer-DAns.D.-40mVRMPFORVARIOUSEXCITABLETISSUES:Neuron:-70mVSkeletalmuscle&Ventricle(cardiacmuscle):-90mVSAnode:-30to-40mVSmoothmuscle:-30to-50mVInnerearhaircell:-150mVRBC:-10mVThyroidgland:-50mVHaircellsbaselinemembranepotential:-60mV
367.Mesangialcellcontractionisdoneby? a)cAMP b)Dopamine c)PAF d)ANP CorrectAnswer-CAns.C.PAFContractionofmesangialcellsisproducedby:-Endothelin,angiotensinII,vasopressin,norepinephrine,PAF,PDGF,thromboxaneA2,PGF2,LeukotrienesC4&D4,Histamine.RelaxationofmesangialcellsisproducedbyANP,Dopamine,PGE2,cAMP.
368.Glomerulotubularfeedbackisfor regulationof? a)BP b)Bloodvolume c)Na+reabsorption d)Renalbloodflow CorrectAnswer-CAns.C.Na+reabsorptionTubulo-glomerularfeedback-RegulationofGFRinrelationtorenalbloodflow.Glomerulo-tubularfeedback-Regulationoftubularreabsorption(especiallyNa+2)inrelationtoGFR.
369.HaldenEffectis? a)CO2deliverybyincreased02 b)02deliverybyincreasedCO2 c)CO2deliverybyincreasedCO2 d)0,deliverybyincreasedCO CorrectAnswer-AAns.A.CO2deliverybyincreased02[Ref:Ganong24n/ep.644&23'd/ep.612]BecausedeoxyhemoglobinbindsmoreH+thanoxyhemoglobindoesandformscarbaminocompoundsmorereadily,bindingofO2,tohemoglobinreducesitsaffinityforCO2,(Haldaneeffect).
370.Tubuloglomerularfeedbackisforregulationof? a)BP b)Bloodvolume c)Na+reabsorption d)GFR CorrectAnswer-DAns.D.GFRToperformthefunctionofautoregulation,thekidneyshaveafeedbackmechanismthatlinkschangesinsodiumchlorideconcentrationatthemaculadensawiththecontrolofrenalarteriolarresistance.Thisfeedbackhelpstoensurerelativelyconstantdeliveryofsodiumchloridetothedistaltubuleandhelpspreventspuriousfluctuationsinrenalexcretionthatwouldotherwiseoccur.ThetubuloglomerularfeedbackmechanismhastwocomponentsthatacttogethertocontrolGFR.
371.GFRmeasurementhelpindetermining? a)Heartrate b)Recoveryfromshock c)Stageofkidneydisease d)Bloodvolume CorrectAnswer-CAns.C.StageofkidneydiseaseGFRisameasureofproperfunctioningofkidney.Itsvaluedeterminesthestageofkidneydisease.
372.Glomerularfilterationofasubstance dependsupon? a)Lipidsolubilityofsubstance b)Bindingcapacitytoalbumin c)Bothoftheabove d)Noneoftheabove CorrectAnswer-BAns.B.BindingcapacitytoalbuminPlasmaproteinbindingofasubstancedecreasesisglomerularfiltration.Onlyunboundsubstancesarefiltered.Glomerularfiltrationdoesnotdependonlipidsolubilityasfiltrationoccursthroughtheporesinglomerularmembrane(Lipidsolubilityaffectsthetransportofsubstanceacrosscellularmembrane)
373.Totalsurfaceareaofrespiratory membrane? a)25cm' b)50cm' c)25m2 d)100m2 CorrectAnswer-DAns.D.100m2[RelPrinciplesofmedicalphysiologyp.340]Thicknessofrespiratorymembraneisabout0.5pmanditstotalsurfaceareaintwothelungsequalsabout100m2.
374.TrueaboutCoronarycirculation? a)250ml/min b)Majorflowduringsystole c)Unifromflowduringfullcardiaccycle d)Alloftheabout CorrectAnswer-AAns,A.250ml/minTheheartreceivesitsbloodsupplyfromtwocoronaryarteriesrightandleftwhicharisefromtherootoftheaorta.Coronarybloodflow,atrest,isabout250mlperminute(5%oftotalcardiacoutput).
375.Damagetopnemotaxiccenteralongwith vagusnervecauseswhichtypeofrespiration? a)Chynestokebreathing b)Deepandslow c)Shallowandrapid d)InspiratorySpasm CorrectAnswer-DAns.D.InspiratorySpasm[RefPrinciplesofmedicalphysiologyp.981).Damagetopneumotaxiccenterormidpontinetransection(betweenupperandlowerpons)produces- 1. Withvagiintact:-Deepandslowbreathing2. Withbilateralvagotomy:Apneusticbreathing(apneusis),i.e. sustainedinspiratoryspasmwhichisinterruptedbybriefandinefficientexpiration.
376.TrueaboutBezold-Jarishreflex? a)Hypertension b)Tachycardia c)Hyperpnea d)Hypotension CorrectAnswer-DAns.D.HypotensionTheventricularbaroreceptorsarescatteredthroughouttheleftventricleandinterventricularseptum.StimulationoftheserecePtorsbyinjectionofcertaindrugs(e.g.,serotonine,veratibine,orniiotine)intotheleftcoronaryarteryproducesapnea,bradycardiaandhypotension.ThisiscalledBezold-Jarischreflexorcoronarychemoreflex.
377.Normaltranspulmonarypressureduring quietbreathing? a)+8to+5cmH20 b)-8to-5cmH20 c)0to+1cmH20 d)0to-1cmH20 CorrectAnswer-AAns.A.+8to+5cmH20Duringquietbreathing,transpulmonarypressureisbetween+8cm(atendofinspiration)and+5cm(atendofexpiration).
378.Positionofstretchreceptorsinleft atrium? a)AVseptum b)Interatrialseptum c)Entranceofpulmonaryvein d)Noneoftheabove CorrectAnswer-CAns.C.Entranceofpulmonaryvein[Refprinciplesofmedicalphysiologp.753]Atrialstretchreceptorsarelocatedatthevariousvenoatrialjunction. 1. Atriocavalreceptorsarelocatedintherightatriumjustatthe entranceofSVCandIVC, 2. Pulmonaryvenoatrialreceptorsarelocatedintheleftatriumjustat theentranceofpulmonaryvein.
379.Organwithdualbloodsupply? a)Heart b)Liver c)Kidney d)Lung CorrectAnswer-B:DAns.(B)Liver(D)LungLiverhasdualsupply-HepaticarteryandportalveinLunghasdualsupply-Pulmonaryarteryandbronchialartery.
380.Bloodpressureisdependanton? a)Cardiacoutput b)Heartrate c)Strokevolume d)Alloftheabove CorrectAnswer-DAns.D.AlloftheaboveArterialbloodpressureistheproductofthecardiacoutputandthetotalperipheralvascularresistance(TPR).Meanbloodpressureisthemajordeterminantofadequatebloodflowthroughthetissues.
381.Oxygensaturationofvenousbloodis? a)30% b)50% c)70% d)90% CorrectAnswer-CAns.C.70%Mixedvenousoxygensaturationisthepercentageofoxygenboundtohemoglobininvenousblood,i.e,bloodreturningtorightsideofheart.Normalvalueis60-80%(average70%)Alsoknow,Arterialoxygensaturationis95-99%(average97%).
382.Isocapenicbufferingis? a)IncrecasedpCO2withincreasedCO2 b)IncrecasedpCO2withdecreasedCO, c)NormalpCO,withincreasedCO2 d)Noneoftheabove CorrectAnswer-CAns.C.NormalpCO,withincreasedCO2*Duringexercise,initiallyCO2productionandincreaseinventilationareproprotionate.-So,pCO2remainsthesame.-Thisiscalledisocapnicbuffering.*But,inlaterstages,ventilationincreasesmorethantherateofCO2production.*Asaresult,PCO2decreases.
383.Afterloadisdecreasedby? a)Exercise b)Anemia c)Thyrotoxicosis d)Alloftheabove CorrectAnswer-DAns.D.AlloftheaboveAfterload(resistanceofferedtoventricularpumpingaction):Leftventriclehastopumpoutbloodagainstaorticresistance.Increasedaorticresistance(e.g.,highBP)tendstodecreasestrokevolume.Decreasedperipheralresistanceincreasescardiacoutpute.g.,inexercises,AVfistulaorshunt,severeanemia(duetovasodilationbyanemichypoxia),thyrotoxicosis(duetovasodilationcausedbyincreasedO2consumption),andwetberi-beri.
384.Vitalcapacityismeasuredby? a)Plethysmography b)Gas-dilutionmethed c)Nitrogenwashouttechnique d)Spirometer CorrectAnswer-DAns.D.SpirometerSpirometrycanmeasure:-Tidalvolume(TV),inspiratoryreservevolume(IRV),expiratoryreservevolume(ERV),vitalcapacity(VC),forcedvitalcapacity(FVC),FEV.Spirometrycannotmeasure:-Residualvolume(RV),functionalresidualcapacity(FRC),totallungcapacity(TLC).
385.Baroreeaptorsarelocatedin? a)Tunicamedia b)Tunicaintima c)Tunicaadventitia d)None CorrectAnswer-CAns.C.TunicaadventitiaBaroreceptorsaremechano-receptorsthatarelocatedintheadventitiaofcarotidarteryandaorta,atspecializedLocationscalledsinuses.
386.STSegmentofECGCorrespordsto whichphaseofactionpotential? a)Rapiddepolarixation b)Rapidrepolarizedtion c)Findrepolarizetion d)PlateuPhase CorrectAnswer-DAns.D.PlateuPhasePhase-2isplateauPhase.
387.Inpatientswithemphysematousbullae, totallungvolumeisbestdeterminedby? a)Spirometry b)Heliumdilutionmethod c)Plathysmography d)Anyoftheabove CorrectAnswer-BAns.B.HeliumdilutionmethodTotallungcapacity(TLC)isdeterminedbyheliumdilutionmethodwhichdoesnotmeasurevolumeinbullae.TLCmeasuredbyplethysmographyincludesthevolumeofbullaealso.Thus,gasvolumeinbullaecanbedeterminedbysubtractingtheTLCdeterminedbyheliumdilutionfromtheTLCdeterminedbyplethysmography.
388.STSegmentofECGcorrespondsto whichphaseofactionpotential? a)Phase0 b)PhaseI c)PhaseII d)PhaseIII CorrectAnswer-CAns.C.PhaseIIRelationofECGwithphasesofactionpotential-Phase0&1=QRScomPlexPhase2=STsegmentPhase3=Twave.
389.Allaretrueaboutcomplianceoflung except? a)ChangeinVolumeperunitchangeinpressure b)TotalComplianceis0.2L/cm c)Ameasureofdistensibility d)Decreasedinemphysema CorrectAnswer-DAns.D.Decreasedinemphysema[Ref.Principlesofmedicalphysiologyp.325,326;Ganong24h/ep.632]Thechangeinvolumeperunitchangeinpressureiscalled'compliance'.Thetotalcomplianceofbothlungstogetherinthenormaladulthumanbeingisabout0.2L/cmwater.Thatis,everytimethetranspulmonarypressureincreasesby1centimeterofwater,thelungvolumewillexpand0.2L(200mI).Complianceisameasureofdispensability.Complianceisincreasedinemphysema.
390.STSegmentofECGCorrespondsto? a)Ventriculardepolarization b)Ventricularrepolarization c)Atrialdepolarization d)AVConduction CorrectAnswer-DAns.D.AVConductionActionpotentialinmyocardialfibershas5phases:0,1,2,3and4.
391.Inrelaxationpressurecurve,inchronic smokersatZerorelaxationpressure? a)Lungvolumeincreases b)Lungvolumedecreases c)Nochangeinlungvolume d)Anyoftheabove CorrectAnswer-AAns.A.LungvolumeincreasesChronicsmokingcausesCOPDwithlossofelasticityoflungandthereishyperinflationoflung.Combinedrecoilpressureoflungsandthoraciccageisinwardlydirectedinhyperinflatedlungs.Aslunglosesitselasticity,thoraciccagedistends(expands)toahighervolumeatzerorelaxationpressure-+Functionalresidualcapacityisincreased.
392.Cerebralbloodflowisincreasedby? a)IncreaseinP02 b)IncreaseinPCO2 c)Decreasemetabolicrate d)Alloftheabove CorrectAnswer-AAns.A.IncreaseinP02[Ref:www.ncbi.nlm.nih.govl]OnemajorfunctionofionchannelsinendothelialcellsisthecontrolofCa2+influxeitherbyadirectmodulationofCa2+influxpathwayorbyindirectmodulationNa+andClchannels.
393.Whichofthefollowingparameter IndicateseliminationofCO2fromlung? a)Pa02 b)pH c)PaCO2 d)HCO,level CorrectAnswer-CAns.C.PaCO2[Ref:Clinicalphysiologyp.712]PaCO2(PartialpressureofarterialCO2)ReflectstheadequacyofthelungsventilationandCO,elimination(knownasrespiratoryparameter).
394.InzerogravityV/Qratiois? a)0.8 b)1 c)2 d)3 CorrectAnswer-BAns.B.1RemovalofgravityresultsinmoreuniformventilationandperfusionthisV/Qshouldbe1.But,inallrecentstudiesithasbeenshown,thatthereareother(non-gravitational)factorswhichcontributestoV/Qmismatch.Thereforeevenatzerogravity,Heterogeneityofperfusionandventilationoccurs.Thus,V/Qratiocannotbe1atzerogravity.But,ingivenscenarioweacceptsimplegravitationalmodel,inwhichV/QratiomustbeI'thoughtheoretically.
395.ActionPotentialincardiacmuscleshas howmanyphases? a)2 b)3 c)4 d)5 CorrectAnswer-DAns.D.5Bloodflow(Q)isthevolumeflowperunittime(cm3/s),whereasvelocityofbloodflow(V)isdisplacementofbloodperunittime(cm/s).Increasingtheradiustwotimeswilldecreasethevelocityby4times.
396.Roleofionchannelsonvascular endotheliumis? a)Ca+influx b)K+efflux c)Na+influx d)Cl-effux CorrectAnswer-DAns.D.Cl-effuxO2therapyisusefulinhypoxichypoxialikehypoventilation(COPD,restrictivedisease)andhighaltitude.Itisnotusefulinanemichypoxia(anemia,COpoisoning),stagnanthypoxia(CHF)andhistotoxichypoxia(cyanidepoisoning)
397.
Aorticvalveclosureoccursinwhichpartofcardiaccycle? a)Beginningofisovolumetriccontraction b)Beginningofventricularejection c)Beginningofisovolumetricrelaxation d)Duringrapidventricularfilling CorrectAnswer-BAns.B.BeginningofventricularejectionLungcapillaryvolume?150ml.
398.Normal02extractionratiooftissues? a)5% b)15% c)25% d)40% CorrectAnswer-CAns.C.25%NormalO2extractionratiois25-30%
399.Poiseuille'sequationstatesthat? a)Bloodflowisdirectlyproportionto2ndpowerofradius b)Bloodflowisdirectlyproportiomto4thpowerofradius c)Bloodflowisinverselyproportionto2ndpowerofradius d)Bloodflowisinverselyproportionto4thpowerofradius CorrectAnswer-DAns.D.Bloodflowisinverselyproportionto4thpowerofradiusMinutevolume:Amountofairbreathedin(inspired)orout(expired)bythelungsinoneminute.So,minutevolume=TidalvolumexRespiratoryrate.Itisatabout6L
400.Guardianangelagainstobesityname givento? a)Adiponectin b)Fibronectin c)HDL d)Insulin CorrectAnswer-AAns.A.AdiponectinAdiponectin,whichhasbeencalleda"fatburningmolecule"andtheguardianangelagainstobesity,directsfattyacidstomusclefortheiroxidation".
401.Whatistheminimumfluidurineoutput forneutralsolutebalance? a)300ml b)400ml c)500ml d)750ml CorrectAnswer-CAns.C.500mlNormally,180Loffluidisfilteredthroughtheglomeruli,whiletheaveragedailyurinevolumeisabout1Lwithaurineconcentrationof290mOsm/L.Thesameloadofsolutecanbeexcretedperdayinaurinevolumeof500mlwhentheurineismaximallyconcentratedi.e,1400mOsm/L;orinavolumeof23.3Lwhentheurineismaximallydilute,i.e,,30-50mOsm/L.
402.Trueaboutbreathingareallexcept? a)Normalbreathingoccurswhentranspulmonarypressureis8-5 cmH,0 b)Compliancedependsonlyonsurfactant c)Expirationduringquitebreathingispassive d)Inspirationisanactiveprocess CorrectAnswer-BAns.B.CompliancedependsonlyonsurfactantComplianceoflungsdependson:- 1. Elasticforcesoflungtissue(one-third).2. Elasticforcescausedbyalveolarsurfacetension. TheretwoforcesoPPosedistensibilityoflungandthereforedecreaselungcompliance.Surfactant,bydecreasingthealveolarsurfacetensionincreaseslungcompliance.
403.Normalvitalcapacityinanadultis- a)1200ml b)2500ml c)3000ml d)4700ml CorrectAnswer-DAns.D.4700ml
404.Boyle'sLawstatesthat? a)P/T=constant b)PV=constant c)PV=nRT d)V/T=constant CorrectAnswer-BAns.B.PV=constantBoyle'slawAtaconstanttemperature,thepressure(P)ofagivenmassisinverselyproportionatetoitsvolume(pdirectlyproportionalto1/v),i.e.,PVconstant.
405.Airremaininginlungafternormal expiration? a)TV b)RV c)FRC d)VC CorrectAnswer-CAns,C.FRCFunctionalresidualcapacity(FRC)istheamountofairremaininginthelungsafteranormaltidalexpiration.
406.Maximumvoluntaryventilationis- a)25L/min b)50L/min c)100L/min d)150L/min CorrectAnswer-DAns.D.150L/min
407.Physiologicaldeadspaceiscalculated by? a)Boyle'slaw b)Dalton'slaw c)Bohrequation d)Charle'slaw CorrectAnswer-CAns.C.BohrequationAnatomicaldeadspace->measuredbysingle-breathN,method.Physiological(total)deadspace>measuredbyBohrequation.
408.BPislessthan40mmHg.Which mechanismofregulationisworking? a)Chemoreceptorreflex b)Baroreceptorreflex c)CNSischemicreflex d)Noneoftheabove CorrectAnswer-CAns,C,CNSischemicreflexChemoreceptorreflexisusefulinregulationofBPwhenitfallstolevelbetween40-70mmHg.ButifBPisbelow40mmHg,thelastrayofhopeforsurvivalistheCentralNervousSystem(CNS)Ischemicresponse.CNSischemicresponseisevokedbyischemiaofCNS.
409.Deoxygenatedbloodisnotseenin? a)Pulmonaryartery b)Pulmonaryvein c)Rightatrium d)Umbilicalartery CorrectAnswer-CAns,C.RightatriumPulmonaryveinscarryoxygenatedbloodfromthelungstotheleftsideofheart(leftatrium).Pulmonaryarterycarriesdeoxygenatedbloodfromrightsideofheart(rightventricle)tothelungRightsideofheart(rightatriumandrightventricle)containsdeoxygenatedblood.Umbilicalarteriessupplydeoxygenatedbloodfromthefetustoplacenta,intheumbilicalcord.
410.Slowestbloodflowisseenin? a)Arteriole b)Veins c)Capillaries d)Venules CorrectAnswer-CAns,C.Capillaries
411.Inhealthyperson,arterialbaroreceptor activityisseenatwhatstagofcardiacsystole? a)Systole b)Diastole c)Both d)None CorrectAnswer-AAns.A.SystoleBaroreceptorsrespondnotonlytopressuremagnitudebutalsotorateofchangeofpressure.Atrest,arterialbaroreceptorsarestimulatedduringthesystolicupstrokeofthepressurepukewove
412.SIunitofpressureis? a)mmHg b)cmHg c)Pascal d)Torr CorrectAnswer-CAns.C.PascalBloodpressureisthelateralpressureexertedbythecolumnofbloodonthewallsofthearteries,MostcommonlyusedunitofBPismmHg.ButrecentlythereisatrendtowardsadoptingIhesystemInternational'd'units(SIunits).InSIunits,thebasicunitforpressureisnewtonpersquaremeter,andiscalledpascal(Pa).
413.Healthyadultcardiacreserveis? a)50-100% b)100-200% c)200-250% d)300-400% CorrectAnswer-DAns,D.300-400%CardiacreserveThemaximumpercentagethatthecardiacoutputcanincreaseabovenormaliscalledisthecardiacreserve.Thus,inthehealthyadultthecardiacreserveis300-400%percent.
414.Criticalclosingpressureis? a)Arterialpressureminusvenouspressure b)Capillarypressureminusvenouspressure c)Pressurebelowwhichcapillariesclose d)Noneoftheabove CorrectAnswer-CAns.C.PressurebelowwhichcapillariescloseThecriticalpressurebelowwhichthecapillariescloseiscalledthecriticalclosingpressure.
415.Allaretrueaboutbaroreceptors,expect ? a)StimulatedwhenBPdecreases b)Afferentsarethroughsino-aorticnerves c)Stimulationcausesincreasedvagaldischarge d)Stimulatenucleusambiguous CorrectAnswer-AAns.A.StimulatedwhenBPdecreasesBaroreceptorsarehighlysensitivetoanychangeinmeanBp.WhenBPrises,baroreceptorsarestimulatedandtheiraferent(throughsinoaorticnerves)stimulatenucleusoftractussolitarus(MIS)whichinhibitsthepressorareaofvasomotercenteri.e.RVLM.Thisresultsindecreasedsympatheticoutflowand,asaresultvasodilatation.Bpcomesdown.
416.Normalvelocityofbloodis? a)40-50cm/sec b)100-150cm/sec c)200-250cm/sec d)250-300cm/sec CorrectAnswer-AAns.A.40-50cm/secMeanbloodvelocityinaortais40cm/sec.
417.Durationofmaximumcontraction dependsupon? a)Absoluterefractiveperiod b)Relativerefractiveperiod c)Both d)Noneofthetwo CorrectAnswer-BAns.B.RelativerefractiveperiodDuringthisperiod,excitabilitygraduallyrecoversandanewactionpotentialcanbeelicitedsoonerwithastrongerstimulus.Actionpotentialsgeneratedveryearlyintherelativerefractiveperioddonotriseassharplyasnormalactionpotentials,andhavealoweramplitudeandshorterduration.Thusdurationofactionpotential(andthuscontraction)dependsuponrelativerefractiveperiod.IfAPisgeneratedearlyinrelativerefractiveperiod,ithasshorterduration.AndifAPisgeneratedaftercompletionofrelativerefractiveperiod,ithaslonger(normal)durationofactionpotential.
418.Stretchimpulseiscarriedby? a)Ia b)lb c)B d)C CorrectAnswer-AAns.A.IaA-alpha,(TypeIa)fibersareprimaryafferentforstretchreflex.
419.Lessmitochondriaareseenin- a)Redfibers b)TypeIfibers c)Whitefibers d)Slowfibers CorrectAnswer-CAns.C.WhitefibersTypeIIfibersarewhitebecausetheylackmyoglobinandhaveafewmitochondria.Theirmetabolismisglycolytic.TypeIIfibersarefasttwitchfiberswithshortdurationoftwitch.
420.Allaretrueaboutredmusclefibers except? a)Moremitochondria b)Glycolyticmetabolism c)Moremyoglobin d)Moreoxidativecapacity CorrectAnswer-BAns.B.Glycolyticmetabolism
421.Integrationcenteroftoniclabyrinthine reflexis? a)Spinalcord b)Medulla c)Midbrain d)Cerebralcortex CorrectAnswer-BAns.B.Medulla
422.Highercenterforrightingreflex? a)Pons b)Spinalcord c)Cortex d)Midbrain CorrectAnswer-DAns.D.Midbrain
423.Rightingreflexisa? a)Strechreflex b)Posturalreflex c)Spinalreflex d)Ocularreflex CorrectAnswer-BAns.B.PosturalreflexPosturereferstothestaticpositionofanypartofthebody.MovementsarethetransitionfromonePosturetotheanother.
424.Jointposition&vibrationsenseis carriedby? a)Act b)A(3) c)AY d)B CorrectAnswer-AAns,A.Act
425.Tonicneckreflexdisappearsatwhatage ? a)1month b)2months c)3months d)6months CorrectAnswer-DAns.D.6months
426.Significanceofabsenceoflossof assymmetrictonicneckreflexin9months? a)Decreasedmuscletone b)Increasedmuscletone c)Normalphenomenon d)Noneoftheabove CorrectAnswer-BAns.B.IncreasedmuscletoneAsymmetrictonicneckreflexisprominantbetween2ndand4thmonths.Persistenceofthisreflexbeyondtheageof5-9monthsoraconstanttonicneckpostureareabnormalandusuallyindicatespasticcerebralpalsy.Inspasticcerebralpalsy,thereisincreasedmuscletonewithhyper-reflexia.
427.Cerebellardamagecausesallexcept? a)Dysmetria b)Hypertonia c)Ataxia d)Past-pointing CorrectAnswer-BAns.B.HypertoniaDamagetothecerebellumleadstoseveralcharacteristicabnormalities,including:AtaxiaHypotoniaDysmetriaReboundphenomenonDecompositionofmovement
428.Whichreceptorgetstimulatedin moderatecold? a)CMR-1 b)VR1 c)VRL-1 d)VR2 CorrectAnswer-AAns.A.CMR-1Oneisreceptorformoderatecold-+CMR-1(coldandmethanolsensitivereceptor-l)Twotypesofvanilloidreceptorsfornoxiousheat(painfulheat):-I4R-landVRL-L.
429.Post-ganglionicparasympatheticfibers are- a)Aa b)A(3 c)A7 d)C CorrectAnswer-DAns.D.CPost-ganglionicautonomicfibers(bothsympatheticandparasympathetic)are'C'typeoffibers.
430.GroupBnervefibersare? a)Sympatheticpreganglionic b)Sympatheticpostganglionic c)Parasympatheticpreganglionic d)Parasympatheticpostganglionic CorrectAnswer-AAns.A.Sympatheticpreganglionic"Inboththesympatheticandparasympatheticdivisions,preganglionicfibersaremyelinatedtypeBfibers".
431.Painreceptorsare? a)Meissnerscorpuscle b)Paciniancorpuscle c)Freenerveendings d)Merkeldisc CorrectAnswer-CAns.C.FreenerveendingsPainreceptorsarefreenerveendings,i.e.theyarenotenclosedinacapsule.
432.Spinalpathwaymainlyregulatingfine motoractivity? a)Anteriorcorticospinaltract b)Rubrospinaltract c)Vestibulospinaltract d)Reticulospinaltract CorrectAnswer-BAns.B.Rubrospinaltract
433.Whatisseeninwithdrawalreflex? a)Extension b)Flexion c)Extensionfollowedbyflexion d)Noneoftheabove CorrectAnswer-BAns.B.Flexion
434.Whichofthefollowinghassame concentrationinCSFandplasma? a)Ca" b)HCO3 c)Glucose d)Cl? CorrectAnswer-BAns.B.HCO3
435.Sweatingismediatedby? a)Norepinephrine b)Epinephrine c)Acetylcholine d)Histamine CorrectAnswer-CAns.C.AcetylcholineNervesupplyofsweatglandisuniqueinthatitksympatheticbutcholinergic(mostothersympatheticsitesarenoradrenergic)
436.Whichthalamicnucleicanproducebasal gangliasymptoms? a)Lateraldorsal b)Pulvinar c)Ventralanterior d)Intralaminar CorrectAnswer-CAns.C.VentralanteriorMotornuclei(ventralanteriorandventrallateral)ofthalamusrelayandprocessmessagesfrombasalganglia(especiallyglobuspallidus)andcerebellumtomotorandpremotorcortex
437.Whichofthefollowingisacerebellar nucleus? a)Caudatenucleus b)Subthalamicnucleus c)Fastigialnucleus d)Pautamen CorrectAnswer-CAns.C.FastigialnucleusCerebellumisdividedinto- 1. CerebellarCortex(external):-Containsfivecellspurkinjecells, granulecells,basketcells,stellatecellsandgolgicell. 2. Deepcerebellarnuclei(external):-Therearefourntcleidmtate, fastigial,globose,andemboliform
438.Salivationofdogwhenfoodisgiven alongwithbellis? a)Conditionedreflex b)Reinforcement c)Habituation d)Innatereflex CorrectAnswer-AAns,A.Conditionedreflex
439.Precentralgyrus&corticospinaltractare essentialfor? a)Vision b)Olfaction c)Auditory d)Voluntarymovement CorrectAnswer-DAns.D.VoluntarymovementPrecentralgyrusistheprimarymotorcortex(Brodmann'sArea4)wheretheimpulseforvoluntaryactivityoriginates.
440.NumberofconesinRetina? a)3-5millions b)10-20millions c)25-50millions d)50-100millions CorrectAnswer-AAns.A.3-5millionsNumberofConesinretinais3-4.5millionswhereasnumberofRodsare90-100millions.
441.Cellbodiesoforexigenicneuronsare presentin? a)Dorsalraphae b)Locuscoerulus c)Lateralhypothalamicarea d)Hippocampus CorrectAnswer-CAns.C.LateralhypothalamicareaARCneuronsalsoprojecttootherhypothalamicnuclei,includingtheorexigenicorexincontainingneuronsinlateralhypothalamicarea,tostimulateapPetite.
442.Whichofthefollowingdoesnothave sympatheticnoradrenergicfibers? a)Bloodvessels b)Sweatgland c)Heart d)Eye CorrectAnswer-BAns.B.Sweatgland
443.Allshouldbefeaturesofasubstanceto measureGFR,except? a)Freelyreabsorbed b)Freelyfelteredacrossglomerulusmembrane c)Notsecretedbykidney d)None CorrectAnswer-AAns.A.FreelyreabsorbedTomeasureGFR,thesubstanceshouldhavefollowingfeatures:- 1. Passfreelyacrosstheglomerularmembrane.2. Neitherreabsorbednorsecretedbykidney.
444.Renalbloodflowis? a)1-1.5L/min b)1.5-2L/min c)2-2-5L/min d)2.5-3L/min CorrectAnswer-AAns.A.1-1.5L/minThetotalrenalbloodflow(RBF)isapproximately1.1-1.3Lt/min.i.e.,22-25%ofcardiacoutput.ThekidneyshaveahighbloodflowInresting,healthy,youngadultmen,renalbloodflowaveragesabout1.2L/min.Thisisabout25%ofthecardiacoutput(5to6L/min).Bothkidneystogetherweighabout300g,sobloodflowpergramoftissueaveragesabout4mL/min.Thisrateofperfusionexceedsthatofallotherorgansinthebody,excepttheneurohypophysisandcarotidbodies.ThehighbloodflowtothekidneysisnecessaryforahighGFRandisnotduetoexcessivemetabolicdemands.
445.BestmeasureforGFR? a)Serumcreatinine b)Urineoutput c)BUN d)PAN CorrectAnswer-AAns.A.SerumcreatinineInulinismoreaccuratemeasureofGFR,butisinconvenientbecauseithastobeinjectedintravascular.Creatinineisnotasaccurateasinulin,butcreatinineisalreadypresentinthebloodinsteady-state,sotheendogenouscreatinineclearancecanbeusedwithoutthenecessityofhavingtoinfuseinulin.
446.Normalrenalthresholdforglucoseisat plasmaglucoselevel? a)100mg/dl b)200mg/dl c)300mg/dl d)400mg/dl CorrectAnswer-BAns.B.200mg/dlThetransportmaximumforglucoseis375mg/minwhereasthefilteredloadofglucoseisonly125mg/min.Theoveralltransportmaximumforthekidneys,whichisnormallyabout375mg/min,isreachedwhenallnephronshavereachedtheirmaximalcapacitytoreabsorbglucose.Thus,Renalthresholdforglucose 1. Atplasmalevels?200mg/dl2. Atfilteredload25Omg/min
447.Hyperosmolarityofrenalmedullaisdue to? a)K b)Na c)glucose d)Cl CorrectAnswer-A:B:DAns.(B)Na(A)K(D)ClThethickascendinglimbofloopofHenleisimpermeabletowaterbutitactivelyreabsorbsNaCl.ThethindescendinglimbofloopofHenleisrelativelyimpermeabletosolutesbuthighlypermeabletowater.Themostimportantcauseofthehighmedullaryosmolarityisactivetransportofsodiumandco-transportofpotassium,chlorideandotherionsoutofthethickascendinglimbofloopofHenleintothemedullaryinterstitium.MostimportantamongalltheseisNaCl,formaintenanceofhighmedullaryinterstitium.
448.Mostimportantextracellularbuffer? a)Phosphate b)Plasmaproteins c)Ammonia d)Bicarbonates CorrectAnswer-DAns.D.BicarbonatesBicarbonates-Bicarbonatesarethemostimportantbuffersinblood.Thisisbecausethecomponentsofthisbuffersystemcanbeadjustedbythebody.TheHCO3-concentrationiscontrolledbythekidneywhilethePCO,iscontrolledthroughpulmonarycirculation.
449."Deltacells"ofstomachsecrete? a)Cholecystokinin b)Gastrin-releasingpeptide c)Somatostatin d)Secretin CorrectAnswer-CAns.C.Somatostatin
450.Sugarsareprimarilyabsorbedin? a)Duodenum b)Jejunum c)Ileus d)Ascendingcolon CorrectAnswer-BAns.B.JejunumAbsorptionofglucose,galactoseandfructoseoccursmainlyinsmallintestine,especiallyintheproximalpartofjejunum.
451.Trypsinogenisconvertedtotrypsinby? a)Combinationof2moleculesoftrypsinogen b)Phosphorylation c)Removaloffewaminoacidsfromtrypsinogen d)Additionofalkylgroup CorrectAnswer-CAns.C.RemovaloffewaminoacidsfromtrypsinogenSeveralenzymesaresynthesizedininactiveforms,calledproenzymes(zymogens).Activatedwhenasmalllengthoftheproteiniscleavedofffromoneendthroughtheactionofspecificprotease.Thiscausesanirreversiblerearrangementofthetertiarystructuretoyieldtheactiveformoftheprotein.Enterokinasecleavestrypsinogentoyieldactivetrypsin.Theenzymecleavesproteinsatsitesofneutralaminoacids,withapreferenceforaromaticorlargealiphaticsidechains.
452.Whichofthefollowingplantcomponents isnotfermentedbygastrointestinalmicroorganisms? a)Lignin b)Cellulose c)Hemicellulose d)Pectin CorrectAnswer-AAns.A.LigninLignin,anon-carbohydratetypeofdietaryfiberisneitherdigested(byendogenoushumanenzymes)norfermentedbygastrointestinalmicroorganisms.
453. LowestpHisseeninwhichofthe gastrointestinalsecretion? a)Gastricjuice b)Bilejuice c)Saliva d)Pancreaticjuice CorrectAnswer-AAns.A.Gastricjuice
454.Dailysalivarysecretionis a)250-500ml b)1000-1500ml c)2000-2500ml d)3000ml CorrectAnswer-BAns.B.1000-1500ml
455.Inhibitionofmyentericplexusresultsin a)Hyperacidity b)Diarrhea c)Decreasedgutmotility d)Increasedsecretions CorrectAnswer-CAns.C.DecreasedgutmotilityMyentericplexusorAuerbach'splexus:-Itisanouterplexuslyingbetweenthelongitudinalandcircularmusclelayer.Themyentericplexuscontrolsmainlygastrointestinalmotilitytherefore,perisalsisrequiresanactivemyentericplexus
456.Primaryhormoneforsecretionofmilk? a)Oxytocin b)Prolactin c)Glucocorticoids d)Relaxin CorrectAnswer-BAns.B.ProlactinLactogenesisisthesynthesisandsecretionofmilkfrombreastalveoli.Thisrequiresprimarilyprolactin
457.Whichofthefollowingisnotstoredin cell a)Insulin b)Cortisol c)Thyroxin d)Renin CorrectAnswer-BAns.B.CortisolPeptidesandaminehormonesarestoredincellswithinsecretoryvesicles.Incontrast,steroidhormonesarenotstoredinsecretoryvesiclebeforetheirsecretion.
458.Bloodtissuebarrierintestisisformed by? a)Basallamina&interstitialcells b)Adjacentsertolicellswithbasallamina c)Basallamina&spermatogonia d)Basallamina&leydigcells CorrectAnswer-BAns.B.AdjacentsertolicellswithbasallaminaJunctionbetweenadjacentsertolicellsformblood-testisbarrier.
459.LHsurgeisassociatedwith? a)Increasedestrogen&decreasedprogesterone b)Increasedestrogen&increasedprogesterone c)Decreasedestrogen&increasedprogesterone d)Decreasedestrogen&increasedprogesterone CorrectAnswer-AAns.A.Increasedestrogen&decreasedprogesteroneAtthetimeofovulation(LHsurge)estrogenlevelishighwhileprogesteronelevelislow.
460.TheintervalbetweenovulationandLH surgeis? a)12-24hours b)24-48hours c)48-72hours d)72-96hours CorrectAnswer-BAns.B.24-48hoursAt36to48hbeforeovulation,theestrogenfeedbackeffectbecomespositive,andthisinitiatestheburstofLHsecretion(LHsurge)thatproducesovulation.
461.Whichhormoneincreaseswithage? a)GH b)Prolactin c)Parathormone d)Insulin CorrectAnswer-CAns,C.ParathormoneParathyroidhormonelevelsrisewithage,whichmaycontributetoosteoporosis,Increasingageaffectsthehormonalsecretionofbody.
462.Thefollowingistheunitforprolactin levelof20inblood? a)mg/ml b)ng/ml c)mg/L d)ng/L CorrectAnswer-BAns.B.ng/mlThenormalprolactinlevelis<20nglml.
463.Humanspermremainsfertileforhow manyhoursinafemalegenitaltract? a)6-8hrs b)12-24hrs c)24-48hrs d)72-96hrs CorrectAnswer-CAns.C.24-48hrsAhumanspermatozoonremainsfertileforatotalof24-48hrs.inthefemalegenitaltract"--TextbookofreproductivesystemOvumremainsfertilefor72hours.
464.Deficiencyofenzymearomataseleadsto deficiencyofwhichhormone? a)Cortisol b)Estrogen c)Testosteron d)Mineralcorticoids CorrectAnswer-BAns.B.EstrogenAromataseistheenzymethatcatalyzestheconversionofandrogensintoestrogens.
465.Afterfirstmeioticdivision,theprimary oocyteremainsarrestedin? a)Diplotenestage b)Pachytenestage c)Metaphase d)Telophase CorrectAnswer-AAns.A.Diplotenestage
466.Allareandrogensexcept? a)Testosterone b)Dihydrotestosterone c)Androstenedione d)17a-hydroxprogesterone CorrectAnswer-DAns.D.17a-hydroxprogesteroneAndrogensaresubstanceswhichcausedevelopmentofsecondarysexcharactersincastratedmalc.Androgensinmaleare- 1. Testosterons2. Dihydrotestosterone(mostpotent)3. Dehydroepiandrosterone4. Androstenedione
467.Chronicatrophyofadrenalglandwill resultinwhichhormonedeficiency? a)CRH b)ACTH c)Cortisol d)MSH CorrectAnswer-CAns.C.CortisolCortisol(themajorglucocorticoid)isreleasedbyadrenalcortex.CRHissecretedbyhypothalamus,andACTHandMSHaresecretedbypituitary.
468.Trueaboutthyroidhormonereceptoris? a)DirectlybindstoTSH b)DirectlybindstoTRH c)Aresurfacereceptors d)CausesnucleartranscriptionafterbindingwithT4 CorrectAnswer-DAns.D.CausesnucleartranscriptionafterbindingwithT4TRHandTSHbindtocellmembranerecePtors(surfacereceptors)'Thyroidhormone(thyroxine)receptorsareintranuclearreceptorswhichinducesynthesisofspecificProteins(transcriptionofproteins)byincreasingexpressionofspecificgene.
469.Afterinjectingtestosteroneina hypoandrogenicmale,whichofthefollowingoccurs? a)DecreasedFSHsecretion b)DecreasedLHsecretion c)Increasedspermatogenesis d)Noneoftheabove CorrectAnswer-BAns.B.DecreasedLHsecretionSystemicallyadministeredtestosteronedoesnotraisethetestosteronelevelinthetestistoagreatdegree(asitisadministeredsystemically),anditinhibitsLHsecretion(testosteroneinhibitsLHsecretionbyinhibitionatbothhypothalamusandpituitarylevels).So,endogenoustestosteronesecretionisdecreased(LHisnecessaryforendogenoustestosteronesecretion).Thus,testisdoesnothavesufficienttestosteronethatisnecessaryfornormalspermatogenesis.Therefore,prolongedadministrationofsystemictestosteronecancauseoligospermiaorazoospermia.
470.Conversionofchondrocyteinto osteogeniccellsiscausedby? a)Insulin b)IGF-1 c)Growthhormone d)Thyroxine CorrectAnswer-B:CAns.(C)Growthhormone(B)IGF-1AspecificeffectofGrowthHormone(GH)onskeletalgrowthistoconvertchondrocytesintoosteogeniccells,thus,causingspecificdepositionofnewbone.Thiseffectonbonegrowthismediatedbyinsulinlikegrowthfactor-l(IGF-I).Thus,conversionofchondrocytesintoosteogeniccells:-Causedby-+growthhormoneWhichismediatedby-IGF-1
471.Inbreastlactiferousductsareformed undertheinfluenceofwhichhormone? a)Eestrogen b)Progesterone c)LH d)FSH CorrectAnswer-AAns.A.EestrogenEstrogenstimulatesproliferationofthelactiferousductswhileprogesteroneisresponsibleforthedevelopmentofmammaryIobules.
472.Implantationoccursafterhowmanydays offertilization? a)3-5days b)5-7days c)7-9days d)>14days CorrectAnswer-BAns.B.5-7daysAbout6-7daysafterfertilizationtheblastocystattachestotheendometrium,aprocesscalledasimplantationorembedding.Normalsiteofimplantationisposteriorwallofuterusclosetofundus.
473.Spermiogenesisrefersto? a)Formationofspermatazoafromspermatogonia b)Formationofspermatazoafromspermatids c)Formationofspermatidsfromspermatocytes d)Formationofsecondaryspermatocytesfromprimary spermatocytes CorrectAnswer-BAns.B.FormationofspermatazoafromspermatidsSpermatogenesisFormationofspermatozoafromspermatogonia,Spermiogenesis-Formationofspermatozoafromspermatids.Thus,spermiogenesisisthelaststepofspermatogenesis.
474.Spermatogenesistakesplacein? a)Epididymis b)Seminiferoustubule c)Ductusdeferens d)Prostate CorrectAnswer-BAns.B.SeminiferoustubuleSpermatogenesisreferstotheprocessofformationofspermatozoa(sperm)fromprimitivegermcells(spetmatogonia).SPermatogenesisbeginsatpubertyandcontinuesthroughoutadultlifetodeclineinoldage.Inhumans,ittakesanaverageof74daystoformamaturespemfromprimitivegermcells.Spermatogenesisoccursinseminiferoustubules.
475.WhichofthefollowingactionofGHis mediatedbyIGF-1 a)Lipolysis b)decreasesinsulin c)Antilipolysis d)Na*retention CorrectAnswer-CAns.(C)AntilipolysisTheactionsofgrowthhormone-mediatedviaIGF-1(somatomedin-C)aretheindirecteffectsofgrowthhormone.Theseinclude-antilipolyticactivity-insulin-likeactivity-proteinsynthesis-epiphysealgrowth.
476.AllofthefollowingstimulateGH release,except- a)Fasting b)Exercise c)Freefattyacids d)Stress CorrectAnswer-CAns.C.FreefattyacidsStimulithatincreasesecretionofGHarehypoglycemia,exercise,fasting,proteinmeals,aminoacids(likearginine),stress,glucagon,Pyrogen,lysinvasopressin,apomorphins,L-dopa&alpha-adrenergics,estrogen,androgensand2-deoryflucose.StimulithatdecreasesecretionofGHareR"EMsleep,glucose,Somatostatin,cortisol,FFA,GHitseif,IGF-1,andmedroxyprogesteron.
477.HalflifeofT3? a)10hours b)1day c)6days d)10days CorrectAnswer-BAns.B.1day
478.Notincreasedinstress? a)ADH b)thyroxine c)GH d)None CorrectAnswer-DAns.D.None.Allthegivenhormonesareincreasedduringstress.
479.Plasmavolumeismeasuredby? a)Inulin b)Evansblue c)Mannitol d)D20 CorrectAnswer-BAns.B.Evansblue
480.Mostcommontypeofcalciumchannels ofskeletalmusclesare? a)Ttype b)Ltype c)Rtype d)Ntype CorrectAnswer-BAns.B.Ltypelnskeletalmuscle,thereisaveryhighconcentrationofL-typecalciumchannels,situatedinT-tubules.
481.Whatistheeffectofmoderateexercise oncerebralbloodflow a)Doesnotchange b)Increases c)Decreases d)Initiallydecreasesthenincreases CorrectAnswer-AAns.A.DoesnotchangeCerebralbloodflowismaintainedduetoautoregulation(between60-160mmHg)inresponsetomoderateexercise.Duringexercise 1. Bloodflowdecreasedin;-Inactiveskeletalmuscles,kidney'liver' GIT. 2. Bloodflowisunalteredinthebrain(duetoautoregulation).3. Bloodflowisincreasedinexercisingskeletalmuscles,heart (coronarycirculation),lung. 4. Initially,itdecreasedduetotheredistributionofbloodtowards musclebutlaterincreasedduetoanincreaseintemperatureofSkin.
482.'Patch-clamp'isusedfor? a)Torecordfacilitateddiffusion b)Torecordflowinvoltagegatedchannel c)Torecordosmoticpressurearoundsemipermeablemembrane d)TorecordRMP CorrectAnswer-BAns.B.TorecordflowinvoltagegatedchannelPatch-clampisusedtorecordcurrentflowthroughasinglevoltage-gatedproteinchannel.
483.Gapjunctions? a)Areabsentincardiacmuscles b)Areabsentinsmoothmuscles c)Arepresentincardiacmusclestotransmitimpulsefromoneto anothermyocyte d)Arepresentincardiacmusclesbutnorole CorrectAnswer-CAns.C.ArepresentincardiacmusclestotransmitimpulsefromonetoanothermyocyteGapjunctionsTheyareintercellularconnectionscalledhemichannelsorconnexons.Theyaremadeupofproteinsubunits"Connexins".Thesecontinuouschannel(connexons)permitssubstances(ionsandother)topassfromonecelltootherwithouthavingtopassthroughthecellmembrane.Gapjunctionistypicallyseenincardiacandsmoothmuscles.Becauseofgapjunctionscardiacmusclebehavesasafunctionalsyncytiumasthesegapjunctionsprovidelow-resistanceBridgeforspreadofexcitationfromonefibertoother-
484.Carbonicanhydraseactivityfoundinall except? a)Brain b)Kidney c)RBC d)Plasma CorrectAnswer-DAns.D.PlasmaCarbonicanhydrase(CAse)isanenzymewhichcatalyzesthereversiblereactionofformationofbicarbonateions,Theenzymeispresentinrenaltubularcells(especiallyPT),gastricmucosa,exocrinepancreas,ciliarybodyofeye,brainandRBC.
485.HalflifeofPrealbuminis? a)2days b)10days c)20days d)40days CorrectAnswer-AAns.A.2days
486.Calmodulinactivates? a)Musclephosphorylase b)Proteinkinase c)2,3DPG d)Glucokinase CorrectAnswer-AAns.A.MusclephosphorylaseCalcium-calmodulincomplexactivatesmyosinlightkinase(myosinkinase)whichisaphosphorylaseandphosphorylatemyosinhead.
487.Duringstarvation,whichlevelincreases ? a)Leptin b)MSH c)Grhelin d)Insulin CorrectAnswer-CAns.C.Grhelin
488.Mechanismofactionofcholecystokinin ? a)Activationofadenylylcyclase b)Openingofionchannels c)ThroughIP3-DAGsystem d)Transcriptionfacters CorrectAnswer-CAns.C.ThroughIP3-DAGsystem
489.WhichhormoneactsonJAK-STAT kinasereceptor? a)TSH b)Thyroxine c)GH d)FSH CorrectAnswer-CAns.C.GH
490.Thyroidhormonebindstowhich receptor? a)Membrane b)Cytoplasmic c)Nuclear d)None CorrectAnswer-CAns.C.Nuclear
491.Normalrangeofserumosmolalityis (mOsm/Kg)? a)280-300 b)250-270 c)300-320 d)210-230 CorrectAnswer-AAns.A.280-300Normalosmolalconcentration(osmolalityofplasmais290mOsm/Kg.
492.Thefollowingistheactionofmelatonin? a)FacilitatesACTHsecretion b)Preventssleepinduction c)Regulatesthecircadiandaynightrhythm d)ReleaseofTSH CorrectAnswer-CAns.C.RegulatesthecircadiandaynightrhythmTheprincipalsecretoryproductofthepinealglandismelatonin.Melatoninsecretionshowsacircadianrhythm,thelevelbeinghigheratnightandloweratday.Thisdiurnalvariationisbroughtaboutbynorepinephrinesecretedbypostganglionicsympatheticnervesthatinnervatethepinealgland.Inthedarknorepinephrine,secretionisincreasedwhichactson-receptorstoincreaseintracellularcAMPandcAMP,inturn,producesamarkedincreaseinN-Acetyltransferaseactivity,anenzymeinvolvedinmelatoninsynthesisfromserotonin.
493.Na+-K+-C1-cotransportercontains? a)5transmembranespanningdomain b)7transmembranespanningdomain c)9transmembranespanningdomain d)12transmembranespanningdomain CorrectAnswer-DAns.D.12transmembranespanningdomainNa+-K+-Cl-cotransporter(cation-chloridecotransporter)has12-transmembranespanningdomainswithglycosylationsitesonextracellularloopbetweenmembranespans7and8.
494.Vonwilebrandfactorissynthesizedby allexcept? a)Endothelialcells b)Megakaryoctyes c)Hepatocytes d)None CorrectAnswer-CAnsC.HepatocytesMostclottingfactorsaresynthesizedinliverexceptacomponentoffactorVIII.FactorVIIIhastwocomponents:- 1. FactorVIIIc(coagulantfactorVIII):-Synthesizedinliver(main source)andkidney. 2. VonWillebrandfactor(vWF):-Synthesizedinendothelium(main source)andmegakaryocytes.
495.FemaleshavelowRBCcountcompared tomalesdueto? a)Lowerythropoietin b)Mensturalbloodloss c)Highestrogen d)Lowstemcells CorrectAnswer-BAns.B.MensturalbloodlossDifferencesinbloodvaluesbetweenmenandwomenresultbecauseofseveralfactors:- 1. MenhavehigherandrogenslevelsandandrogensstimulateRBC production. 2. Womenofreproductiveagelosebloodthroughmenstruation,which lowerbloodcells. 3. Womentypicallyhavemorefatthanmen,andthehigherthebody fatcontent,thelowerthehematocritlevel.
496.ATPaseactivityispresentin a)Actin b)Myosin c)Troponin d)None CorrectAnswer-BAns.B.MyosinMyosinistheproteinthatconstitutesthethickfilaments.Myosinofskeletalmuscleismyosin-IIMyosinparticipatesinthecontractilemechanismandalsofunctionsasanATPase.
497.Normalferritinlevelinadultmale? a)5-10ng/ml b)100-200ng/ml c)500-700ng/ml d)800-900ng/ml CorrectAnswer-BAns.B.100-200ng/mlNormalserumferritinMales-30-400ng/mlFemales-30-200ng/ml
498.Dailywaterlossinsweatduringnormal activities? a)50-100ml b)200-400ml c)500-700ml d)1000-1200ml CorrectAnswer-AAns.A.50-100mlFluidlossinsweat:Thisishighlyvariable,anddependsonphysicalactivityandenvironmentaltemperature.Thevolumeofsweatnormallyisabout100ml/day.
499.Ionicreceptorsareallexcept? a)NMDA b)Kainate c)mGluR d)AMPA CorrectAnswer-CAns.C.mGluRInotropicreceptorsInotropicreceptorsaretransmembraneionchannelswhichallowdifferentkindsofiontotravelinandoutofthecell.Bindingofneurotransmitter(ligand)eitheropenorclosetheionchannel.Therefore,inotropicreceptorsare"Ligandgatedtransmembraneionchannels,"Examplesofinotropicreceptorsare:- 1. Forglutamate-AMPA,Kainate,NMDA2. ForGABA:GABA(a)recePtors3. Foracetylcholine:Nicotinic(Nm,Nn)4. Forserotonin-5HT3
500.Differenceintheamountof02inspired andCO2expired? a)20ml/min b)50ml/min c)75ml/min d)100ml/min CorrectAnswer-BAns.B.50ml/min250mlofO2entersthebodyperminuteand200mlofCO2isexcreted.
501.Venousbloodwithhighhematocritis seenin? a)RBChighchloride b)PlasmahighNa c)PlasmahighHCO3 d)RBChighK CorrectAnswer-AAns.A.RBChighchlorideHematocritofvenousbloodisnormally3%greaterthanthatofarterialblood.
502.Dailypancreaticsecretion? a)1.5L b)2.5L c)5.0L d)10L CorrectAnswer-AAns.A.1.5L
503.Microcirculationconsistsof? a)Capillaries b)Capillariesvenulesandarterioles c)Aorta d)Arteriesandveins CorrectAnswer-BAns.,B.CapillariesvenulesandarteriolesThemicrocirculationconsistsofarteriolestovenules,i.e.arterioles,capillariesandvenules.
504.Gasexchangeintissuestakesplaceat? a)Artery b)Capillary c)Vein d)Venules CorrectAnswer-BAns.B.CapillarySiteofgasexchange=Capillaries
505.Durationof2"heartsoundis? a)0.15sec b)0.12sec c)0.08sec d)0.1sec CorrectAnswer-BAns.B.0.12sec
506.Einthovenslaw- a)I+III=II b)I-III=II c)I+II+III=0 d)I+III=avL CorrectAnswer-AAns.A.I+III=IIEinthoven'sLawstatesthatiftheelectricalpotentialsofanytwoofthethreebipolarlimbelectrocardiographicleadsareknownatanygiveninstant,thethirdonecanbedeterminedmathematicallybysimplysummingthefirsttwo(butnotethatthepositiveandnegativesignsofthedifferentleadsmustbeobservedwhenmakingthissummation).ThusthesumofthevoltagesinleadsIandIIIequalsthevoltageinleadII.
507.Vasoconstrictioninskin? a)Sympathetic b)Parasympathetic c)Whealandflare d)Warmclimate CorrectAnswer-AAns.A.SympatheticSympatheticstimulationactingviaalpha1and2arevasoconstrictortotheskinarterioles.
508.Normalinterstitialpressureis? a)10to15mmHg b)-5to0mmHg c)20to30mmHg d)-10to-20mmHg CorrectAnswer-BAns.B.-5to0mmHgNormalinterstitialfluidhydrostaticpressure(orsimplyinterstitialpressure)isusually-1mHg.Howeveritvariesaccordingtotissuesandrangesfrom-5mmHgto-1mmHg.Itisslightlysubatmosphericinmostofthetissues.
509.Striatumdamageaffectsprimarily? a)Proceduralmemory b)Shorttermmemory c)Longtermmemory d)Explicitmemory CorrectAnswer-AAns.A.ProceduralmemoryProceduralmemoryisatypeofimplicitmemorythatenablesustocarryoutcommonlyleanedtaskswithoutconsciouslythinkingaboutthem,e.g.,ridingabike,tyingashoeorwashingdishes.Proceduralmemorylikelyusesadifferentpartofbrainthanepisodicmemory-withbraininjuryyoucanloseone'sabilitywithoutlosingother.That'swhyapersonwhohasexperiencedamnesiaandforgetmuchabouthisorherpersonallifeoftenretainsproceduralmemoryi.e.,howtodriveacaroruseaforketc.Striatum(apartofbasalganglia)isresponsibleforprocedurememory.
510.Somatosensorycortexlesionwillcause ? a)Pain b)Temperature c)Localization d)Vibration CorrectAnswer-CAns,C,LocalizationCorticallesionsdonotabolishallthesomaticsensations.Corticalanesthesiamainlyinvolvelossofproprioceptionandtactilesensations(finetouch,twopointdiscrimination,astereognosisorstereoanesthesia.Painandtemperatureareleastaffected,buttheyarepoorlylocalization.
511.Settingposturebeforeplanned movement? a)Premotorcortex b)Motorcortex c)Frontal d)Supplementarymotorcortex CorrectAnswer-AAns.A.PremotorcortexThepremotorcortexfunctionisstillincompletelyunderstood,butitmaybeconcernedwithsettingpostureatthestartofaplannedmovementandwithgettingthelndividualpreparedtomove.Itismostinvolvedincontrolofproximallimbmusclesneededtoorientthebodyformovement.
512.Neuronsinsympatheticgangliaare? a)Unipolar b)Bipolar c)Pseudounipolar d)Multipolar CorrectAnswer-DAns,d.MultipolarVentral,lateralanddorsalhornsofspinalcordandsympatheticchaingangliacontunmultigolarneuron,whereasdorsalrootgangliacontainspseudounipolarneurons.
513.Pt.isabletorecognisepersonbyname butnotbyface.Lesionisin? a)Postparietalregion b)Occipital c)Frontallobe d)Temporallobe CorrectAnswer-DAns.D.TemporallobeAnimportantpartofthevisualinputgoestotheinferiortemporallobe,whererepresentationsofobjects,particularlyfacesarestored.Inhumans,storageandrecognitionoffacesismorestronglyrepresentedintherightinferiortemporallobeinright-handedindividuals.
514.CSF/plasmaglucoseratiois? a)0.2-0.4 b)0.6-0.8 c)1.2-1.6 d)1.6-2.2 CorrectAnswer-DAns.D.1.6-2.2
515.Burningpainiscarriedbywhichtypeof fibres? a)Aalpha b)Adelta c)Abeta d)C CorrectAnswer-DAns.D.CPainistransmittedviatwofibertypes:*ThinlymyelinatedAdeltafibers(2-5mindiameter)whichconductatratesof12-30m/s.*UnmyelinatedCfibers(0.4-1.2mindiameter)whichconductatlowratesof0.5-2m/s.-Thermoreceptorsalsospanthesetwoflbertypes.-ColdreceptorsareondendriticendingsofAdeltafibersandCfibers,whereaswarmth(heat)receptorslueonCfibers.
516.Amansleptwithheadoverforearm,next morninghecomplainsoftingling,numbnessoverforearm.Itiscausedby? a)SensitivitytohypoxiaisA>B>C b)SensitivitytopressureisA>B>C c)SensitivitytohypoxiaisC>B>A d)SensitivitytopressureisB>A>C CorrectAnswer-CAns.C.SensitivitytohypoxiaisC>B>ATypeCfibers(TypeIVLloyd&Hunt)areleastsusceptibletohypoxia'
517.Lesionofpreopticnucleusof hypothalamuscauses? a)Hyperphagia b)Hyperdypsia c)Hyperthermia d)Hyperglycemia CorrectAnswer-CAns.C.HyperthermiaPreopticnucleusisconcernedwithregulationofbodytemperature.Therefore,itslesionwillresultindefectivetemperature
518.Thedistancebywhichtwotouchstimuli mustbeseparatedtobeperceivedastwoseparatestimuliisgreatestat? a)Thelips b)Thepalmofthehand c)Thebackofscapula d)Thedorsumofthehand CorrectAnswer-CAns.C.ThebackofscapulaThemagnitudeoftwopointdiscriminationthresholdsvariesfromplaceofplaceonthebodyissmallestwheretouchreceptorsaremostabundant.stimulationpointsonthebackmustbeseparatedbyatleast65mmbeforetheycanbedistinguishedasseparate,whereasonthefingertipstwostimuliassrecognizediftheyareseparatedbyaslittleas2mm.
519.Purkinjefibresareinhibitoryfor? a)Deepcerebellarnuclei b)Climbingfibre c)Basketcells d)Spinocerebellartracts CorrectAnswer-AAns.A.DeepcerebellarnucleiAftercomplexinhibitingandexcitatoryinteractionsofvariousfibersandcellsinthecortex,theoutputofcerebellarcortex,isprojectedtodeepcerebellarnucleibyaxonsofpyramidalcells(onlyoutputcellsofcerebellarcortex).TheoutputofthePurkinjecellsisinhibitoryinthedeepcerebellarnuclei.However,theoutputofdeepcerebellarnucleitothebrainstemandthalamusisalwaysexcitatorybecause,besideinhibitoryinputsofpurkinjecells,deepcerebellarnucleialsoreceiveexcitatoryinputsfromafferentmossyandclimbingfiberswhichusuallyaremoreprominent.
520.Neurotransmitterinvolvedin nigrostriatialpathwayis? a)Serotonin b)Dopamine c)Cholinergic d)Adrenergic CorrectAnswer-BAns.B.DopamineDopaminergicnigrostriatalprojectionfromthesubstantianigraparscompacta(sNpc)tothestriatumCaudatenucleusandputrrnen)andcorrespondingGABAergicproiectionfromstriatumtosubstantianigraparsreticulate(SNPR).Dopamineisthemajorneurotransmitterinsubstantianigra.
521.Lossofproprioception&finetouch? a)Anteriorspinothalamictract b)Lateralspinothalamictract c)Dorsalcolumn d)Corticospinaltract CorrectAnswer-CAns.C.Dorsalcolumn
522.Trueaboutspinocerebellartractis? a)Equilibrium b)Smoothensandcoordinatesmovement c)Learninginducedbychangeinvestibuloocularreflex d)Planningandprogramming CorrectAnswer-BAns.B.SmoothensandcoordinatesmovementSpinocerebellumisconcernedwithsmootheningandcoordinationofmovements.Itachievesthisbygettingamomenttomomentreportbyspinocerebellartract.
523.Saltytaseisdueto? a)Ca+2channels b)Na+channels c)G-protein d)H+channels CorrectAnswer-BAns,B.Na+channelsSalty-tastingsubstancesdepolarizetastecellsbyactivatingamiloride-sensitiveNa+channels.
524.Epinephrinereducesinsulinby? a)Alphaactionpredominantly b)Betaactionpredominantly c)Alphaandbeta d)Muscarinicreceptors CorrectAnswer-AAns.A.AlphaactionpredominantlyEpinephrinedecreasesinsulinreleaseviaalpha-2actionaspancreaticbeta-cellshasalpha-2receptors.
525.Adrenalineeffectsinsulinby? a)Stimulationofalphacells b)Stimulationofbetacells c)Stimulationofdeltacells d)Stimulationofgcells CorrectAnswer-BAns.B.StimulationofbetacellsAdrenalinedecreasesinsulinsecretionbyactingonalpha-2receptorsonbeta-cellsofpancreas.
526.Motormarchisseenin? a)Axontemesis b)Neurotemesis c)Neuropraxia d)Nerveregeneration CorrectAnswer-AAns.A.AxontemesisMotormarch(sequentialreinervationofmusclesfromproximaltodistal)isseeninaxontemesis.InneuroPraxiathereisnoanatomicdisruption,somotormarchisnotseen.Inneurotemesisthereisnorecovery,thusnomotormarch'
527.Whenthetensioninamusclefibreis maximum,itslengthiscalledas? a)Equilibriumlength b)Optimumlength c)Initiallength d)None CorrectAnswer-BAns.B.OptimumlengthUptoalimitgreatertheinitiallength(i.e.,lengthatrelaxed-state)greateristheforceofcontraction.I.e.,thereisanoptimallength,atwhichtheforcegeneratedbyamuscleismaximal'
528.Tetaniccontractionisdueto accumulationof? a)Na+ b)Ca+ c)K+ d)Cl? CorrectAnswer-BAns.B.Ca+Tetaniccontractionisaboutfourtimesthetwitchtension,Followingtheoryhasbeenputforwardforthishighertensiongeneratedduringmuscletetanus:-Duringasingletwitch,theamountofCa+2isreleasedintosarcoplasmisnotenoughtoproducetetanictension.Whenthemuscleisstimulatedinrapidsuccession,Ca+2comesoutintothesarcoplasmwitheachstimulusandthereisaprogressiveaccumulationofCa+2,inthesarcoplasm.TetanictensionisreachedwhensarcoplasmicCa+2levelsreachtheirmaximum.
529.Duringacclimitisation,decreased sweatingisduetodownregulationof? a)Epinephrinereceptors b)Norepinephrinereceptors c)Acetylcholinereceptors d)Dopaminereceptors CorrectAnswer-CAns.C.AcetylcholinereceptorsExaminerjustwantstoknowthereceptorswhicharepresentinsweatgland.Sweatingisunderthecontrolofsympatheticsystem.Buttheneurotransmitterisacetylcholinewhichactsoncholinergicsympatheticreceptors.
530.Substancethatiscompletelyreabsorbed fromthekidney? a)Na+ b)K+ c)Urea d)Glucose CorrectAnswer-DAns.D.GlucoseOnanormaldietmaximumsolutesarereabsorbedalmostcompletely:-Glucose,Aminoacids&HCO3-:100%
531.Substratewhichisbothsecreted& filtered? a)UricAcid b)Glucose c)Urea d)Na+ CorrectAnswer-AAns,A.UricAcidSubstanceswhicharebothsecretedandfilteredareK+,uricacidandcreatinine.
532.ANPactsatwhichsite? a)Glomerulus b)LoopofHenle c)PCT d)Collectingduct CorrectAnswer-DAns.D.CollectingductTheatrialnatriureticpeptides(ANPs)arepresentasgranulesintheatrialmusclecells.ANPisreleasedinresponsetoincreasedplasmaNa+concentration.Ingeneral,theeffectsofANParephysiologicallyantagonistictothoseofangiotensinII.ANPcausesnatriuresisduetoincreasedGFRbyrelaxingmesangialcellsofglomerulus.ANPdecreasestheNa+reabsorptionfromthedistaltubuleandcollectingduct.ANPdecreasesthesecretionofrenin,aldosterone,andADH.Inaddition,NPalsorelaxesthevascularsmoothmuscleinarteriolesandvenulesandthereforelowersBP.
533.AsfluidcomesdownthePCT,whatis true? a)Concentrationofureafalls b)ConcentrationofHCO3-falls c)ConcentrationofNa'increases d)Concentrationofinulindecreases CorrectAnswer-DAns.D.Concentrationofinulindecreases
534.Whichofthefollowingismostimportant insodiumandwaterretention? a)Renninangiotensinsystem b)ANP c)BNP d)Vasopressin CorrectAnswer-DAns.D.VasopressinDespiteitseffectonNa+andwaterreabsorption,aldosteroneisaweakregulatorofbodyNa,andwaterbalance,themajorregulatorbeingthe'thirst-ADH'mechanism.Aldosteroneisthesoleregulatorofexternalpotossiumbalance".
535.Cephalicphaseofgastricsecretion? a)20% b)70% c)10% d)100% CorrectAnswer-AAns.A.20%Cephalicphaseaccountsfor20%ofgastricacidsecretionandgastricphaseaccounts70-80%ofgastricacidsecretion.
536.Cephalicphaseofgastricsecretion? a)Onfoodenteringstomach b)Onfoodenteringintestine c)Onseeingfood d)Onstress CorrectAnswer-CAns.C.OnseeingfoodThecephalicphaseofgastricsecretionoccursevenbeforefoodentersthestomach,especiallywhileitisbeingeaten.Itresultsfromthesight,smell,thought,ortasteoffood,andthegreatertheappetite,themoreintenseisthestimulation.
537.Motilinsecretiondecreasedin? a)Thirsty b)Starving c)Ingestedmeal d)Interdigestivestate CorrectAnswer-CAns.C.IngestedmealWhenamealisingested,secretionofmotilinissuppresseduntildigestionandabsorptionarecomplete.
538.WhichismaximallyabsorbedfromGIT? a)Pentose b)Hexose c)Diasaccharide d)Polysaccharide CorrectAnswer-BAns.B.HexoseHexosesarerapidlyabsorbedacrossthewallofthesmallintestine.
539.Pancreaticlipasehydrolysesester linkageoftriacidglyceridesatposition? a)1&2 b)1&3 c)2&3 d)Only3 CorrectAnswer-BAns.B.1&3Mostfatdigestionthereforebeginsintheduodenum,pancreaticlipasebeingoneofthemostimportantenzymesinvolved.Thisenzymehydrolyzesthe1-and3-bondsofthetriglycerides(triacylglycerols)withrelativeeasebutactsonthe2-bondsataverylowrate,sotheprincipalproductsofitsactionarefreefattyacidsand2-monoglycerides(2-monoacylglycerols).Itactsonfatsthathavebeenemulsified.
540.Gastricsecretionsareessentialfor absorptionof- a)Cobalmin b)Fat c)Thiamine d)Folicacid CorrectAnswer-AAns.A.CobalminVitaminB12isabsorbedintheileum.Thisvitaminbindstointrinsicfactor,aproteinsecretedbythestomach,andthecomplexisabsorbedacrosstheilealmucosa.
541.EffectofaceytylcholineonLES? a)Contraction b)Relaxation c)Noeffect d)Contractionfollowedbyrelaxation CorrectAnswer-AAns.A.ContractionThisbarrieragainstrefluxoftheharmfulgastricjuice(pepsinandHCDisstrengthenedwhenthesplincterpressureisraisedby- 1. Acetylcholine2. Adrenergicagonists3. Gastrin4. Motilin5. Somatostatin6. SubstanceP7. Histamine8. PGF2-alpha.9. Proteinrichfood 10. Highintraabdominalpressure.
542.Ptylinissecretedby? a)Gastricgland b)Salivarygland c)Duodenalgland d)Pancreaticgland CorrectAnswer-BAns.B.SalivaryglandSalivaryamylaseisalsocalledptylinwhichissecretedinsalivabysalivarygland.
543.PGsinsemenaresecretedby? a)Prostate b)Seminalvesicle c)Sperms d)Testes CorrectAnswer-BAns.B.Seminalvesicle
544.17OHsteroid? a)Androgen b)Progesterone c)Estrogen d)None CorrectAnswer-BAns.B.Progesterone
545.GLUT2ispresentmainlyin? a)Betacellsofpancreas b)Placenta c)Skeletalmuscle d)Cardiacmuscle CorrectAnswer-AAns.A.Betacellsofpancreas
546.Glucosetransporterinvolvedininsulin stimulatedglucosetransportisGLUT? a)1 b)2 c)3 d)4 CorrectAnswer-DAns,D.4
547.Insulinisessentialforglucoseentryin? a)Muscle b)Corticalneurons c)Renaltubularcells d)Betacellsofpancreas CorrectAnswer-AAns.A.MuscleGlucoseenterscellsbyfacilitateddiffusionor,intheintestineandkidneys,bysecondaryactivetransportwithNa+.Inmuscle,adipose,andsomeothertissues,insulinstimulatesglucoseentryintocellsbyincreasingthenumberofglucosetransporterslnthecellmembranes.
548.Wolff?Chaikoffeffectisdueto? a)SuppressionofTSHsecretion b)DecreasediodinationofMIT c)DecreasedT3toT4conversion d)Iodineintake CorrectAnswer-DAns.D.IodineintakeIodineisthefastestactingthyroidinhibitor.Themostimportantactionisinhibitionofhormonerelease(thyroidconstipation),butallfacetsofthyroidsynthesismaybeaffected.Excessiodideinhibitsitsowntransportinthyroidcellsandmayaltertheredoxpotentialofcells,thusinterferingiodinationreducedT3/T4synthesis(Wolff?Chaikoffeffect).
549.Majoradrenalandrogenis? a)Testosterone b)11-hydroxyderivativeofandrostenedione c)17-ketosteroiddehydroepiandrosterone d)Cortisol CorrectAnswer-CAns.C.17-ketosteroiddehydroepiandrosteroneThemajoradrenalandrogenisthel7-ketosteroiddehydroepiandrosterone,althoughandrostenedioneisalsosecreted.Themajorandrogenoftestisistestosterone.
550.DiurnalvariationofACTHdependson? a)Suprachiasmaticnucleus b)Supraopticnucleus c)Ventrolateralnucleus d)Thalamus CorrectAnswer-AAns.A.SuprachiasmaticnucleusThebiologicclockresponsibleforthediurnalACTHrhythmislocatedinthesuprachiasmaticnucleiofthehypothalamus.
551.Hypothalamusincreasesreleaseofall hormonesfromthepituitaryexcept? a)TSH b)FSH c)CRH d)Prolactin CorrectAnswer-DAns,D.ProlactinFormostoftheanteriorpituitaryhormones.ltisthereleasinghormonethatareimportantbutprolactinismainlyundertheinhibitorycontrol.
552.1stresponsetohypoglycemia? a)Decreasedinsulin b)Increasedglucagon c)Increasedcortisol d)Increasednorepinephrine CorrectAnswer-AAns.A.DecreasedinsulinDecreasedinsulinisthefirstresponsefollowedsuccessivelybyincreaseinglucagon,epinephrine,cortisolandGH.
553.Velocityofhumansperm- a)1-3mm/min b)4-6mm/min c)6-9mm/min d)10-13mm/min CorrectAnswer-AAns.A.1-3mm/minHumanspermmoveataspeedof-3mm/minthroughthefemalegenitaltract.Spermsreachuterinetubes30-60minutesaftercopulation.
554.Acidophilssecrete a)GH b)TSH c)ACTH d)FSH CorrectAnswer-AAns.A.GHAcidophilsoftheanteriorpituitarysecretesgrowthhormoneandprolactin.
555.Vasopressinissecretedby a)Supraoptic b)Preoptic c)Paraventricular d)Posteriornucleus CorrectAnswer-AAns.A.SupraopticADHisformedprimarilyinthesupraopticnuclei,whereasoxytocinisformedprimarilyintheparaventricularnuclei".
556.Growthhormoneleveldecreasedin a)Hypoglycemia b)Fasting c)Sleep d)Exercise CorrectAnswer-CAns.C.SleepREMsleepdecreasesGHsecretionwhereasSlow-wavesleep(N3ofNREM)causesanincreaseinGHsecretion.
557.Pituicytesareseenin? a)Anteriorlobe b)Posteriorlobe c)Intermediatelobe d)All CorrectAnswer-BAns.B.PosteriorlobePituicytesareglialcellsofposteriorpituitary.
558.Sizeofsperm? a)100microns b)65nm c)100nm d)65microns CorrectAnswer-DAns.D.65microns
559.cAMPactionmediatesallexcept? a)Glucagon b)Folliclestimulatinghormone c)Leutinizinghormone d)Estrogen CorrectAnswer-DAns.D.Estrogen
560.InThyroidfollicleforhowlongThyroxine isstored? a)2-3weeks b)2-3days c)2-3months d)2-3years CorrectAnswer-CAns.C.2-3monthsThyroidhormonesarestoredinthefolliclesinanamountsufficienttosupplythebodywithitsnormalrequirementsofthyroidhormonesfor2to3months.
561.Ghrelinfalseis? a)Producedbystomachcells b)Increasedappetite c)Isrelatedtoregulationofthyroidhormone d)Stimulatesgrowth CorrectAnswer-CAns.C.IsrelatedtoregulationofthyroidhormoneGhrelinissecretedprimarilybythestomachandappearstoplayanimportantroleinthecentralcontroloffoodintake.ItalsostimulatesgrowthhormonesecretionbyactingdirectlyonrecePtorsinthepituitary.Itisalsoproducedinthehypothalamusandhasmarkedgrowthhormone-stimulatingactivity.
562.IsotopeusedtomeasureRBCvolumeis ? a)Cr51 b)H3 c)D20 d)I135 CorrectAnswer-AAns.A.Cr51BloodcellvolumeismeasuredbyCr51labeledRBC.
563.Glucoseistransportedinrenaltubular cellsby a)Ksymport b)Kantiport c)Naantiport d)Nacotransport CorrectAnswer-DAns.D.NacotransportSodium-dependentglucosetransporters,SGLTIandSGLT2,areresponsibleforthesecondaryactivetransportofglucoseintheintestineandrenaltubules.GlucoseandNa+bindtothesodium-dependentglucosetransPorter(SGLT)2intheapicalmembrane,andglucoseiscarriedintothecellasNa+movesdownitselectricalandchemicalgradient.
564.Watertravellingfromextracellularto intracellularisby? a)Co-transport b)Diffusion c)Filtration d)Activetransport CorrectAnswer-BAns.B.DiffusionBestanswerofthisquestionisnonebecausetransportofwater(solvent)acrossthecellmembraneiscausedbyosmosis.Allthegivenoptionsarethetransportprocessesofsoluteacrossthecellmembrane(notforsolvent).Howeveramongthegivenoptions,diffusionistheclosestone:"Diffusionofsolventtowardsanareawherethereishigherconcentrationofsoluteiscalledosmosis".
565.Osmolarityisdefinedas? a)Numberofosmoleperlitre b)Numberofosmoleperkg c)Weightofsoluteperlitre d)Weightofsolventperlitre CorrectAnswer-AAns.A.NumberofosmoleperlitreOsmolarity>Numberofosmoleperlitre.Osmolality>Numberofosmoleperkg.
566.Insensiblewaterlossperdayis? a)100ml b)300ml c)700ml d)1000ml CorrectAnswer-CAns.C.700mlInsensiblewaterloss-Thereiscontinuouslossofwaterbyevaporationfromrespiratorytractanddiffusionthroughtheskin,whichtogetheraccounts700ml/dayofwaterlossundernormalconditions.Theinsensiblewaterlossfromskin(diffusionthroughskin)occursindependentlyofsweatingandaccounts350mlofwaterlossperday.So,intheabsenceofsweating,waterlossfromtheskinis350ml/day
567.Whichofthefollowingincreasesparticle diffusionacrossthecellmembrane? a)Increasingsizeofparticle b)Decreasinglipidsolubilityofsubstance c)Increasinglipidsolubilityofsubstance d)Decreasingsizeofopeningincellmembrane CorrectAnswer-CAns.C.IncreasinglipidsolubilityofsubstanceSimplediffusionisfavoredbysmallsize,lipidsolubilityandabsenceofpolarity(non-polarsubstance)andcharge(neutralmolecule)throughathin,largemembranewheretheconcentrationgradientismore.
568.Mostpotentantioxidant? a)VitA b)VitK c)VitE d)VitC CorrectAnswer-CAns.C.VitEVitaminE(tocopherol)isthemostinpotentantioxidantinthebody,actinginthelipidphaseofmembranesprotectingagainsttheeffectsoffreeradicals.
569.Inmoderateexcercisetherespiratory rateisincreasedduetoresponseof? a)Propioceptionreceptorinthejoints b)PCO2inarterialblood c)PO2inarterialblood d)J-receptorstimulation CorrectAnswer-AAns.A.PropioceptionreceptorinthejointsInmoderateexercisetheabruptincreaseinventilationatthestartofexerciseisduetopsychicstimuliandafferentimpulsesfromproprioceptorsinmuscles,tendonsandjoints.
570.Myosinfilamenthasafixedlengthof a)0.16nm b)1.6micrometers c)16nm d)l.6mm CorrectAnswer-BAns.B.1.6micrometersThetotallengthofeachmyosinfilamentisuniform,almostexactly1.6micrometers.
571.Plasmamembraneismainlycomposed of? a)Cholesterol b)Carbohydrate c)Phospholipid d)Protein CorrectAnswer-DAns.D.Protein
572.Onweightbasis,themembranecontains proteinandlipidintheratioof? a)1:2 b)1:1 c)2:1 d)4:1 CorrectAnswer-BAns.B.1:1Thecellmembranecontainsproteinsandlipidsina50:50ratio.Thisreferstotheratiooftheirmassesandnotnumbers".Itisworthnotingherethatabovedescribedpercentageisintermsofareaoccupied.However,intermsofmasses,thecellmembranecontainsproteinsandlipidsina50:50ratio.
573.Whichreceptorsareblockedin MyastheniaGravis? a)Achreceptors b)Ca++receptors c)Na2+receptors d)Opioidreceptors CorrectAnswer-AAnswer:A-AchreceptorsAnautoimmunediseaseAntibodymediatedautoimmuneattackofacetylcholinereceptors.InabilityofneuromuscularjunctionstotransmitsignalsfromnervetomuscleResultinginmuscleweaknessandfatigability.Unresponsiverespiratorymusclesmaycauserespiratoryfailureinseverecases.AnalysisofneuromusculartransmissionrevealDecreaseinacetylcholinereceptors(AChRs)Lossofpost-junctionalfolds.Circulatingantibodiestoacetylcholinereceptorspositive.Diagnosis:Clinicaltest:Strengthimprovementinresponsetoadministrationofanticholinesteraseagents.Treatment:Anti-cholinesterasedrugs:Allowsaccumulationoflargeramountsofacetylcholineinsynapticjunctions.Neostigmine.
574.WhatisProsopagnosia? a)Impairmentofconsciousness b)Beingunawareofone'sproblems c)Difficultyinidentifyingknownfaces d)Failuretoidentifyobjects CorrectAnswer-CAns.C.Difficultyinidentifyingknownfaces.AfeatureofanxietydisorderProsopagnosiaisdifficultyinidentifyingknownfacesOtherfeaturesofanxietydisorderinclude,MemoryimpairmentwithoutimpairmentofconsciousnessBeingunawareofone'sproblem(Agnosognosia)
575.WhatisthecharacteristicpatternseeninBrownsequard syndrome- a)C/Llossofjointsenseandposition b)C/Llossofpain c)I/Llossofcompletesensoryfunctions d)C/Lmotorfunctions CorrectAnswer-BAnswer:B-ContralaterallossofpainsensationsIfthespinalcordiscompletelytransected?Allthesensationsandmotorfunctionsdistaltosegmentoftransectionareblocked.Transectionofspinalcordonsinglesideresultsin"BrownSequardSyndrome"Functionsaffected: Function Position Description affectedMotor Ipsilateralside Completelossofmotorfunctionsbelowtheleveloftransection Sensory Combinedeffects Somesensoryfunctionsareobserved lostontransectedsideand othersonoppositeside. Onthe Resultofdisturbancein Contralateral Spinothalamicpathway. side: Lossobserved2to6 Sensationofpain, segmentsbelowthelevelofcold,&heat transection. DiscreteCrude Poorlylocalized(Still touch persists).
PartialtransmissionoccursinoppositeSpinothalamictract
576.Insulinlikegrowthfactorissecretedby: a)Liver b)Pituitarygland c)Pancreas d)Adrenalglands CorrectAnswer-AAnswer:A.LiverGrowthhormoneactsonthelivertoformsmallproteinscalled"Somatomedins"SomatomedinsincreasesbonegrowthinallaspectEffectsaresimilartoinsulin,hencereferredtoas"Insulin-likeGrowthFactor"(IGF).Fourtypesavailable-MostimportantisSomatomedinC-Specificallyreferredtoas"Insulin-GrowthFactor-1/IGF-1"BindstoacarrierproteininbloodHence,alongerdurationofactionthangrowthhormone.Half-life-about20Hrs(comparedtogrowthhormone-20mins)BloodconcentrationofIGF-1followsthelevelsofgrowthhormone.GrowtheffectsofGHaremostlyattributedtosomatomedin(ratherthanitsdirecteffectonbones&peripheraltissues)
577.WhenVa/Qisinfinity? a)PartialpressureofO2becomeszero b)NoexchangeofO2&CO2 c)PartialpressureofCO2alonebecomeszero d)PartialpressurebothCO2andO2remainnormal CorrectAnswer-BAnswer:B-NoexchangeofO2&CO2Varepresentstheventilationinalveoli.Qrepresentsthebloodflowthroughthealveolus.TheratioofVaandQexplainstherespiratoryexchangewhenthereisanimbalancebetweenalveolarventilationandalveolarbloodflow.Theventilation-perfusionratioisconsiderednormalthereisanequalamountofbloodflow&ventilationthroughalveolus.Va/qratioisZero-Thereisinadequateornil,butperfusionpersistsVa/qratioisinfinity-Thereisadequateventilationbutnoperfusion.BothintheZeroandinfinityVa/Qratio,thereisnoexchangeofgasesthroughtherespiratorymembranesofcorrespondingalveoli.WhenVa/Qratioisinfinity,ThealveolarairequilibratesthehumidifiedinspiredairNoexchangeofoxygenandcarbon-di-oxideoccurs.PartialpressuresoftheO2andCO2are149mmHg&0mmHgrespectively
578.Glucoseisabsorbedinintestineby? a)Secondaryactivetransport b)Facilitateddiffusion c)Simplediffusion d)Primaryactivetransport CorrectAnswer-BAnswer:B.FacilitateddiffusionFacilitateddiffusionisadiffusionoflargewatersolublemoleculebyacarrierprotein.Glucoseandaminoacidsaretransportedacrossthemembranebythismethod.
579.Cwaveisseenin- a)Iso-volumetriccontraction b)Slowfillingatendofdiastole c)Endofsystole d)Startofdiastole CorrectAnswer-AAns.A.Iso-volumetriccontractionCwave:ProducedbybulgingoftricuspidvalveintorightatriumduringIso-volumetriccontractionofrightventricle.
580.Componentsresponsibleforcounter currentmechanisminkidneyareallexcept: a)Sodiumoutflowinthickascendinglimb b)Wateroutflowinthindescendinglimb c)Sodiumoutflowinthinascendinglimb d)FlowoftubularfluidfromPCTtoDCT CorrectAnswer-CAnswer:C.SodiumoutflowinthinascendinglimbCounter-currentsystemoccursinkidneyAsysteminwhichinflowrunsparallelto,counterto,andincloseproximitytotheoutflowforsomedistance.2countercurrentmechanismsavailable:CountercurrentmultiplieratLoopofHenleGeneratehighmedullaryosmoticgradientpressureCountercurrentexchangeratvasarectaofmedullarycapillariesHelpsinmaintainthemedullaryosmoticpressuregradientSubstancesinvolvedincountercurrentmechanisminclude:Sodiumactivelyabsorbedwithco-transportofpotassium&chlorineinthickascendinglimbofloopofHenle.WaterreabsorbedinthindescendinglimbofloopofHenle.Ureadiffuseoutfromthemedullarycollectingductsintomedullaryinterstitium.
581.Alphawavesareseenduring? a)Sleep b)REMmovements c)Relaxedstate d)Activestate CorrectAnswer-CAnswer:C-RelaxedstateRegardedasnormalwavefrontOccurwhenatrestandeyesclosedwithactive/wanderingmindie.,associatedwithadecreasedlevelofattention(eitherduringrelaxed/subconsciousthinking)RegularRhythm(Frequency8-13HzAmplitude-50-100V)
582.Inhypovolemicshockthereis- a)Afferentarteriolarconstriction b)Efferentarteriolarconstriction c)Increasedbloodflowtokidney d)Normalcardiacoutput CorrectAnswer-AAnswer:A.AfferentarterioleconstrictionInadequatecirculationvolume.Poorvenousreturntoheartwilldecreasethestrokevolume&cardiacoutput.Compensationbytachycardia&increasedsystemicvascularresistance(SVR).Becomecoldperipherally(shutdown).Mostcommoncauses-FluidlossofanyetiologyHemorrhageSalt&waterlossSepsisBurns
583.Aldosteronesynthesisisstimulatedbywhichofthe following? a)ACTH b)Hyperkalemia c)Hypernatremia d)Exogenoussteroids CorrectAnswer-BAns.B.HyperkalemiaMineralocorticoidsecretionisstimulatedbyhyperkalemia,angiotensin-II,ACTHandhyponatremia,inreducingorderofefficacy.1.Aldosteronesecretioninresponsetohyperkalemiaisthemostimportantandformsthebasisforrenalregulationofbodypotassiumbalance.2.StimulationofaldosteronebyangiotensinII(throughtherenin-angiotensinsystem)isimportantforthecorrectionofhypovolemiaandhypotensioninconditionslikesaltdepletionorrenalischemia.3.StimulationofaldosteronesecretionbyACTHresultsindiurnalvariationofaldosteronesecretion.However,ACTHisnotanimportantphysiologicalregulatorforaldosteronesecretion.4.Hyponatremiaisaweakstimulatorofaldosteronesecretion
584.WhenthevalueofV/qisinfinity,it means? a)NoO2goesfromalveolitobloodandnoco2goesfromblood toalveoli b)Deadspace c)ThePO2ofalveolarairis159mmHgandPCO2is40mmHg d)PartialpressureofO2andCO2areequal CorrectAnswer-BAns:B.DeadspaceDeadspaceAnareawithventilationbutnoperfusion.*V/Qundefined,thoughapproachinginfinity.InterpretationsofV/Qratiovalues:*Valueis0.8-Ventilation-Perfusionmatching*IfV/Qis>0.8?-Thismeansmoreventilationthanperfusion.*IfV/Qis<0.8?-V/QmismatchRef:ArvindArorareviewbookofphysiology(p.240-241)
585.Proteoglycanpresentintheglomerular basementmembraneis? a)Keratansulphate1 b)Keratansulphate2 c)Heparansulphate d)Chondroitinsulphate CorrectAnswer-CAns:c.HeparansulphateTheglomerularmembrane(orthefiltrationbarrier)isthefiltrationsurfacethroughwhichthefluidisfilteredoutfromtheblood.Theglomerularmembrane(filtrationbarrier)comprises:*Theglomerularcapillaryendothelium.*Thebasementmembrane(basallamina).*TheBowman'svisceralepithelium(podocytes).*Importantconstituentsofglomerularmembraneinclude,-Laminin-Type4collagen-Nidogen-Proteoglycans-(Heparansulphate)Ref:ArvindArorareviewbookofphysiology(p.371-372)
586.35yroldfemalewaswatchingTVforlong hourswithhandsunderherhead.Shecomplainsoftinglingsensationoverherarm.Whichtypeofnervefibersismostlikelytobeaffected? a)Fibers b)B-fibers c)C-Fibers d)Sympatheticnervefibers CorrectAnswer-AAns:A.Fibers A- Features: Functions: High delta Diameter- Pain- susceptibleto 1-5 -"Fast/Epicritic/First"pain. Pressure Myelination- -Sincefibersarerelatively Somemyelination fastConduction-5-30 Temperature PressureTouch Ref:ArvindArorareviewbookofphysiology(p.58-59)
587.Thereflexinwhichthereisinhibitionof gastricemptyingwhenthereisacidandhypertonicsolutionintheduodenum? a)Enterogastric b)Gastroileal c)Gastrocolic d)Myenteric CorrectAnswer-AAns:A.EnterogastricTheenterogastricreflexisoneofthethreeextrinsicreflexesofthegastrointestinaltract,theothertwobeingthegastroilealreflexandthegastrocolicreflex.Theenterogastricreflexisstimulatedbyduodenaldistension.ItcanalsobestimulatedbyapHof3-4intheduodenumandbyapHof1.5inthestomach.Themainneuralinfluenceingastricemptyingisthoughttobemediatedviaaninhibitorymechanismreferredtoastheenterogastricreflex.Fats,fattyacids,soaps,proteindigestiveproducts,acids,andhypertonicsolutionsinthesmallintestineinhibitmotility.Ref:https://www.gastrojournal.org/article/S0016-5085(75)80295-2/pdf
588.Inmultiplesclerosis,slowconductionof motorandthesensorypathwaysisdueto? a)DefectinthenodeofRanvier b)Lossofmyelinsheath c)Leakingofsodiumchannels d)Leakingcalciumchannels CorrectAnswer-BAns:B.LossofmyelinsheathMultipleSclerosis(MS)isadisablingprogressiveneurologicaldisorderThepathophysiologyofMSresultsindisruptionorlossofaxonalmyelininthecentralnervoussystem(CNS),leadingtotheformationofscartissue(sclerosis).Demyelinationproducesalterationsinsaltatoryconduction,slowedconductionvelocity,andapredispositiontoconductionblockRef:https://www.physiology.org/doi/pdf/10.1152/japplphysiol.00460.2010
589.Whichofthefollowingclottingfactorinapatienton Warfarintherapy,wouldhavedecreasedgammacarboxyglutamateresidue? a)Factor2 b)Factor11 c)Tissuefactor d)Factor5 CorrectAnswer-AAns:A.Factor2VitaminKisacofactorfortheenzymaticconversionofglutamicacid(Glu)residuestogamma-carboxyglutamicacid(GLA)invitaminK-dependentproteins,viatheendoplasmicreticulumresidentvitaminK-dependentgamma-glutamylcarboxylase.Thiscarboxylaseactivityisfoundinessentiallyallmammaliantissues,anditsreactionproduct,Gla,hasbeenobservedinbothvertebratesandinvertebrates;bothplayanimportantbiologicalroleinproteinfunction.VitaminK?dependentclottingfactordeficiency(VKCFD)isarareautosomalrecessivebleedingdisorderthatoftenpresentswithseverehemorrhageduringinfancy.Arareinheritedformofdefective-carboxylationresultingintheearlyonsetofbleedingwasfirstdescribedbyMcMillanandRobertsin1966andsubsequentlyhasbeentermedvitaminK?dependentclottingfactordeficiency(VKCFD).CombineddeficiencyofvitaminK?dependentclottingfactorsII,VII,IX,andX(andproteinsC,S,andZ)isusuallyanacquiredclinicalproblem,oftenresultingfromliverdisease,malabsorption,orwarfarinoverdose.
Patientsplasmashowedlessthan3%activityoffactorsII,VII,IX,andX.
590.Bloodstoredincitrate-phosphate-dextroseisbetterfor hypoxicpatientsthanacidic-citrate-dextrosebecause? a)IthaslessP50 b)Itislessacidic c)Thefallin2,3DPGisless d)Noneoftheabove CorrectAnswer-CAns:C.Thefallin2,3DPGislessTheinfusionofACDbloodcausedP50and2,3-DPGconcentrationtodecreasesignificantly.Theinfusionofbloodstoredincitratephosphatedextrose(CPD)didnotsignificantlyincreasetheoxygenaffinity.Tocompensatefortheincreasedoxygenaffinity,theremustbeariseincardiacoutputormorelikelyadecreaseinvenousPO2.ThetransfusionofCPDblood,therefore,ismorefavorableintermsofoxygensupply,particularlyinpatientswhohavehadcardiacsurgery.
This post was last modified on 23 November 2021