Download MBBS Nephrology PPT 6 Nephrology Basics Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Nephrology PPT 6 Nephrology Basics Lecture Notes


Nephrology ? Basics
Renal Physiology

? Glomerular Filteration
? Tubular Function
? Endocrine Functions

? Renal blood flow normally drains pproximately

20% of the cardiac output, or 1000 mL/min.

? Blood reaches each nephron through the

afferent arteriole leading into a glomerular

capillary where large amounts of fluid and

solutes are filtered to form the tubular fluid.


? The distal ends of the glomerular capil aries coalesce to

form an efferent arteriole leading to the first segment

of a second capil ary network (cortical peritubular

capil aries or medul ary vasa recta) surrounding

the tubules.

? Thus, nephrons have two capil ary beds arranged in a

series separated by the efferent arteriole that

regulates the hydrostatic pressure in both capil ary

beds.

? The distal capil aries empty into smal venous branches

that coalesce into larger veins to eventual y form the

renal vein.


? The proximal tubule is responsible for

reabsorbing ~60% of filtered NaCl and water,

as well as ~90% of filtered bicarbonate and

most critical nutrients such as glucose and

amino acids.

? The proximal tubule uses both cellular and

paracellular

transport

mechanisms.
? The loop of Henle consists of three major

segments: descending thin limb, ascending thin

limb, and ascending thick limb.

? These divisions are based on cel ular morphology

and anatomic location, but also correlate with

specialization of function.

? Approximately 15?25% of filtered NaCl is

reabsorbed in the loop of Henle, mainly by the

thick ascending limb.

? The loop of Henle has an important role in

urinary concentration by contributing to the

generation of a hypertonic medullary interstitium

in a process cal ed countercurrent multiplication.

? The loop of Henle is the site of action for the

most potent class of

diuretic agents (loop diuretics) and also

contributes to reabsorption of calcium and

magnesium ions
? The distal convoluted tubule reabsorbs ~5% of

the filtered NaCl.

? This segment is composed of a tight

epithelium with little water permeability.

? The collecting duct modulates the final

composition of urine.

? The two major divisions, the cortical collecting

duct and inner medullary collecting duct,

contribute to reabsorbing ~4-5% of filtered

Na+ and are important for hormonal

regulation of salt and water balance.


Arteries/brain/adrenals

Kidneys/adipose tissues
Renal Function Tests

? Blood Urea
? Serum Creatinine
? Serum Electrolytes
? Serum Calcium
? Serum Phosphate

Urine Examination

? Dip stick
? Microscopy
? 24 hrs Urine
Renal Imaging

? Skiagram
? USG
? CT scan
? MRI

This post was last modified on 07 April 2022