Which nephron segment is responsive to aldosterone and involved in salt reabsorption?

The nephron segment that responds to aldosterone and is involved in salt reabsorption is the collecting duct. Aldosterone is a steroid hormone produced by the adrenal cortex that plays a crucial role in regulating blood pressure and sodium and potassium levels. It acts primarily on the distal tubule and collecting duct of the nephron.

In response to aldosterone, the principal cells in the collecting duct increase the reabsorption of sodium ions (Na+) from the filtrate back into the bloodstream. This process also leads to water reabsorption indirectly, as the reabsorbed sodium creates an osmotic gradient that promotes water retention, ultimately contributing to an increase in blood volume and pressure.

While other nephron segments like the proximal convoluted tubule and the ascending limb of the loop of Henle do play roles in reabsorption of salts and water, they are not directly influenced by aldosterone. The proximal convoluted tubule is primarily responsible for the reabsorption of a significant proportion of filtered sodium and other solutes but operates independently of aldosterone. The ascending limb of the loop of Henle reabsorbs sodium through active transport but is not responsive to aldosterone either. The descending loop does not participate in salt reabsorption at all; it