Question

Glucose is mainly absorbed in
(a) Henle’s loop
(b) DCT
(c) PCT
(d) Nephron

Answer 1

Hint: Different parts of nephron work in a different manner to produce highly concentrated urine. Reabsorption of various useful substances like glucose, water, electrolytes mainly occurs in the initial parts of the nephron. The epithelial cells of this region are specialized for the transport of salts and other substances from lumen to interstitial fluid.

Complete step by step answer:
- PCT is involved in the absorption of glucose.
- The first part of the nephron is the PCT. It has a simple brush bordered cuboidal epithelium.-The membranes of these cells have numerous microvilli which increase the surface area.
- Many electrolytes, water, water-soluble vitamins, and glucose are absorbed by this part of the nephron.

- Other than absorption, PCT is involved in the selective secretion of ions like hydrogen ions, ammonia, and potassium ions into the filtrate to maintain pH and ionic balance.
- They also absorb bicarbonate ions from body fluid.
- Near its basolateral surface, mitochondria are concentrated to allow reabsorption of salts by active transport.

Additional information:
- After PCT comes the Henle’s loop where different mechanisms are involved to maintain high osmolarity of the interstitial fluid.
- In DCT the sodium ions and water reabsorption takes place.
- Collecting duct also plays an important role in maintaining pH and ionic concentration as well as in producing highly concentrated urine.
- Malpighian corpuscle, PCT, and DCT are located in the renal cortex.
- Duct of Bellini, a loop of Henle, and collecting duct are present in the renal medulla.
So, the correct answer is ‘(c) PCT’.

Note: When glucose is not absorbed properly by the nephron, excretion of glucose takes place through urine. This condition is called Glycosuria. This sign is present in Diabetes mellitus. This disease is mainly caused due to less secretion of insulin.