Zoology - Excretory Products and their Elimination Question with Solution | TestHub

A. Functions of Proximal Convoluted Tubule (PCT)
$1.$PCT absorbs almost all essential nutrients.
$2.$PCT absorbs about 70-80 % electrolytes and water.
$3.$As PCT selectively secretes H+ ions, ammonia and potassium ions into the filtrate and also absorbs${\mathrm{H}\mathrm{C}\mathrm{O}}_3^{-}$
from it, it maintains the pH and ionic balance of the body fluids.
B. Functions of Henle's Loop
$1.$Maintenance of high osmolarity of medullary interstitial fluid.
$2.$Reabsorption to some extent (some water and electrolytes enter medullary fluid).
C. Functions of Distal Convoluted Tubule (DCT)
$1.$Conditional reabsorption of${\mathrm{N}\mathrm{a}}^{+}$and water.
$2.$Reabsorption of${\mathrm{H}\mathrm{C}\mathrm{O}}_3^{-}$and selective secretion of${\mathrm{H}}^{+},\mathrm{ }{\mathrm{K}}^{+,}$and${\mathrm{N}\mathrm{H}}_3$for maintaining the pH and sodium-potassium balance in the blood.
D. Functions of Collecting Duct
$1.$Reabsorbed of large amounts of water resulting in the production of concentrated urine.
$2.$Small amounts of urea enter the medullary interstitium to keep up the osmolarity.
$3.$By the selective secretion of${\mathrm{H}}^{+}$and${\mathrm{K}}^{+}$ions, collecting ducts also plays an important role in the maintenance of pH and ionic balance of the blood.