Question

The maximum amount of electrolytes and water (70-80 percent) from the glomerular filtrate is reabsorbed in which part of the nephron?
A.Ascending limb of the loop of Henle
B.Distal convoluted tubule
C.Proximal convoluted tubule
D. Descending limb of the loop of Henle

Answer 1

Hint:The renal tubule of nephron consist of the proximal convoluted tubule, Henle's loop, and Distal convoluted tubule, and the part where maximum reabsorption of water and electrolytes occur is a very highly coiled network.

Complete answer:
-A nephron is made up of two parts that are glomerulus and the renal tubule.
-The renal tubule starts from the Bowman's capsule and extends to form a highly coiled network that is PCT, Henle's loop which is hairpin shaped, and distal convoluted tubule which is also a highly coiled part of the nephron.
-Proximal convoluted tubule is lined by cuboidal epithelium which is simple and brush- bordered and is responsible for the maximum reabsorption of water and electrolytes and all the important nutrients present in the filtrate.

Option A: The ascending limb of the loop of Henle is only responsible for minimum reabsorption of water and electrolyte is not reabsorbed in this part. Therefore, this is the incorrect option.

Option B: Distal Convoluted tubule shows conditional reabsorption of water and sodium ion. Therefore, this is the incorrect option.

Option C: proximal convoluted tubule is the most important part for reabsorption of important nutrients and it absorbs maximum water and electrolyte to concentrate the filtrate so that excess of water is not lost from the body, it also regulates PH of filtrate, Therefore, this is the correct option.

Option D: Descending limb of Henle's loop reabsorb a little number of electrolytes only, Therefore, this is the incorrect option.

Hence, the correct answer is option Option C.

Note:
-The brush border epithelium of PCT has microvilli which increases the surface area of PCT so that it can reabsorb the maximum amount of water and electrolytes.
-PCT maintains the ionic balance of the filtrate by absorption of carbonate ions from filtrate and secretion of hydrogen ion, potassium ion, and ammonia into the filtrate.
-Proximal convoluted tubule is also known as pars convoluta.