Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Physiology 63 Plasma Proteins PPT-Powerpoint Presentations and lecture notes
Plasma Proteins
Learning Objectives:
At the end of this lecture student should be able to discuss-
Types of plasma proteins
Characteristics of plasma proteins
Functions of plasma proteins
Hypoproteinemia and oedema
Plasma proteins
Plasma contains ~ 7% protein,
Normal total plasma protein is about 6.3- 8.4 g/dl
Classes of Plasma Proteins
Albumins - 60%
Globulins (, , ) - 35%
Fibrinogen - 4%
Other proteins - 1%
Site of synthesis of Plasma Proteins
Liver - 90% plasma proteins
Plasma cel (B lymphocytes) - globulin
Peptide hormones ? Endocrine glands
Liver dysfunction - plasma proteins
A:G ratio (normal): 0.8-2.0., Decreased in liver
dysfunction and chronic inflammatory conditions.
Plasma protein - Albumin
? Forms - 55%-60% of total plasma proteins
? Normal value - 3.5-5.0 g/dl
? Molecular Weight (MW)- 66,500 D (lightest)
Structure - a single peptide chain of 585 amino acids
Plasma protein - Albumin
? Major function: Plasma Col oid Osmotic Pressure
? Carrier
Hypo-albuminemia
Liver disease,
Malnutrition
Chronic infection
.
Plasma protein - Globulin
? Forms ? 35% of total plasma proteins
? Normal value - 2-3 g/dl; ? Molecular Weight (MW)-90,000-150000 D
? Type - Three types of globulin have been identified -- alpha, beta, & gamma.
Fibrinogen
? Forms ? 4%-6% of total plasma proteins
? Normal value - 0.3-0.4 g/dl; .? Molecular Weight (MW)-4,00,000-500000 D
? It is a plasma clotting factor, important for blood coagulation as can be
converted into insoluble fibrin Molecules form clots, Produce long, insoluble
strands of fibrin
? It also contributes to the viscosity of blood.
Other Plasma Proteins
1% of plasma proteins:
Regulatory proteins (cel ular products) (1%):
Hormones,
Enzymes, and
Prohormones
Methods of plasma protein separation
Common methods of protein separation into:
albumin, globulins (alpha, beta & gamma) and fibrinogen by ?
Electrophoresis
Salting out
Ultracentrifugation
Affinity chromatography
Fractional precipitation method
Immune electrophoresis
Hypo-proteinemia
? Liver failure
? Nephrotic syndrome
? Malnutrition
? Malabsorption
? Severe burns
? Infection (catabolism)
? Genetic
Functions of plasma proteins
1. Col oid osmotic pressure in blood
2. Viscosity of blood
3. Buffer action
4. Clotting and fibrinolysis
5. Defense function body
6. Transport function
7. Plasma proteolytic enzyme system
8. Plasma protease inhibitor system
9. Nutritional reserve
Colloid osmotic pressure (oncotic pressure)
80% of plasma oncotic pressure is maintained by albumin.
It is the opposing force to hydrostatic pressure.
Col oid osmotic pressure (oncotic pressure) and filtration of fluid
Edema
Due to disturbance in hydrostatic and/or oncotic pressure between
intra-capillary and interstitial component.
Organ specific
? Brain: Cerebral edema
? Lung: Intra-alveolar=pulmonary edema,
intra-pleural=pleural effusion
? Peritoneum=ascites
? Severe generalized edema=anasarca
? Leg edema- deep venous thrombosis
Facial oedema
EdemaPitting Non pitting
Clinical y
Pitting Non pitting
Clinical Problem Based Question
A previously wel 9 year old girl presents to your office
with the chief complaint of facial puffiness. Her mother
noticed this a few days ago and it seems to be worsening. She
has no other symptoms, but about two weeks ago had "a bad
cold." On examination HR 90/min, RR 20/min, BP 92/55 mm of
Hg. Abdomen is soft, non-tender. Her face shows moderate
puffiness and periorbital edema. The dorsal surfaces of his
hands and feet also have mild pitting edema. Urinalysis shows
4+ protein, Blood -protein of 2 g/dL, serum albumin of 1.4 g/dL
Que.1 What is the provisional diagnosis?
Que.2 What is the cause of facial puffiness and feet edema?
Fill in Blanks
? Reduced plasma osmotic pressure leads to a net movement of fluid into the --------
------------ subsequent -----------------plasma volume.
? ------------------capil aries permeability results in increased capil ary hydrostatic
pressure, causing------------------.
? Patients having acute cardiac failure do not show oedema, because
1.The plasma oncotic pressure is high
2.There is renal compensation
3.There is an increase in cardiac output
4.There is a fal in the systemic capil ary hydrostatic pressure
This post was last modified on 08 April 2022