Looking for classes? Ksquare Career Institute, Bengaluru →
Which one of the following statements in regard to the excretion by the human kidneys is correct?
A
Ascending limb of Loop of Henle is impermeable to electrolytes
B
Descending limb of Loop of Henle is impermeable to water
C
Distal convoluted tubule is incapable of reabsorbing $HCO_3^-$
D
Nearly 99 percent of the glomerular filtrate is reabsorbed by the renal tubules
Detailed Solution
The kidneys form about 180 litres of glomerular filtrate per day, but only about 1.5 litres of urine is released.
This shows that nearly 99 per cent of the filtrate is reabsorbed by the renal tubules. This statement is correct.
The ascending limb of Henle's loop is impermeable to water but allows the transport of electrolytes (actively or passively).
The descending limb is permeable to water but almost impermeable to electrolytes.
The distal convoluted tubule is capable of reabsorbing $HCO_3^-$ and of selectively secreting $H^+$, $K^+$ and $NH_3$ to maintain the pH and sodium–potassium balance of blood.
Hence the correct statement is that nearly 99 percent of the glomerular filtrate is reabsorbed.
This shows that nearly 99 per cent of the filtrate is reabsorbed by the renal tubules. This statement is correct.
The ascending limb of Henle's loop is impermeable to water but allows the transport of electrolytes (actively or passively).
The descending limb is permeable to water but almost impermeable to electrolytes.
The distal convoluted tubule is capable of reabsorbing $HCO_3^-$ and of selectively secreting $H^+$, $K^+$ and $NH_3$ to maintain the pH and sodium–potassium balance of blood.
Hence the correct statement is that nearly 99 percent of the glomerular filtrate is reabsorbed.