Question

Absorption of $Na^+$ and $K^+$ ion does not occur in
A) Bowman’s capsule
B) Loop of Henle
C) Distal Convoluted Tubule
D) Proximal Convoluted Tubule.

Answer 1

Hint: The absorption of sodium and potassium ions takes place in the nephrons. Bowman’s capsule, Loop of Henle, DCT, PCT are the parts of the nephron where filtration, secretion, reabsorption and excretion of the water, glucose, ions take place.

Complete answer:
Nephrons are the structural and functional units of Kidneys. It comprises renal corpuscles and tubules.

Renal corpuscles contain the glomerulus and the bowman’s capsule where ultrafiltration takes place.
In this, all the components of the blood are filtered except proteins. In this, the metabolic wastes are separated and the urine is formed. It happens at high pressure. The Bowman’s capsule is the place where filtration takes place. Reabsorption of the ions does not take place in renal corpuscles.

The renal tubules comprise PCT, DCT, Loop of Henle. Most of the reabsorption takes place in the renal tubules.
- Proximal Convoluted Tubule- It receives the urine filtered from the Bowman’s capsule. In this part, most of the sodium and potassium are reabsorbed from the urine. The other molecules absorbed are water, chloride ions, glucose, amino acids and bicarbonates.
- Loop of Henle- It is a U-shaped tube that extends from the PCT. The role of this is to reabsorb sodium chloride and water.
- Distal convoluted tubule- It extends from Henle’s loop. The role of DCT is secretion. It secretes ammonium and hydrogen ions.
- Collecting duct- It is the last part of the nephron. It generates concentrated urine.

Therefore the correct answer is option ‘A’.

Note: Sodium and potassium are the most important ions needed by our body. They help in muscle contraction and also in the transmission of nerve impulses. The movement across the membranes is due to the difference in the sodium and potassium gradient.