Question

The part of a nephron involved in active reabsorption of sodium is:
(a) Distal convoluted tubules
(b) Proximal convoluted tubules
(c) Bowman’s capsule
(d) Descending limb of Henle’s loop

Answer 1

Hint: In order to deliver only a small amount of ${Na}^{+}$ ions to downstream sites, the function of this is to reabsorb most of the filtered ${Na}^{+}$ ions; these latter sites can then adjust their reabsorption rate of ${Na}^{+}$ ions to attain balance in the steady-state for this cation.

Complete step by step answer:
Sodium reabsorption occurs exclusively in proximal and distal convoluted tubules by tubular reabsorption. In the active reabsorption of sodium into the peritubular capillary network and passive flow of water flows, the proximal convoluted tubule is involved. 67 percent of sodium reabsorption accounts for it. DCT sodium reabsorption is also an active procedure but is subject to hormonal control, i.e. conditional response.

So, the correct answer is ‘Proximal convoluted tubules’.

Additional information: The nephron section that lies immediately downstream of the macula densa is the distal convoluted tubule. The distal convoluted tubule plays a critical role in sodium, potassium, and divalent cation homeostasis, although it is short in duration.
At the beginning of the tubular portion of a nephron in the mammalian kidney, the Bowman capsule (or the Bowman capsule, capsula glomeruli, or glomerular capsule) is a cup-like sack that performs the first step in the filtration of blood to form urine. The sac is surrounded by a glomerulus.
Henle Loop, a long U-shaped part of the tubule that carries urine to reptiles, birds, and mammals inside each nephron of the kidney. The key feature of Henle's loop is to recover urine from water and sodium chloride.

Note: The proximal convoluted tubule (PCT) has a high reabsorption power, which is why it has advanced features to help with this. To increase the surface area on the apical side, it is lined with simple cuboidal epithelial cells that have a brush margin.