Question

Which of the following causes an increase in reabsorption in distal convoluted tubule?

• A. Decrease in aldosterone
• B. Increase in antidiuretic hormone levels
• C. Increase in aldosterone
• D. Decrease in antidiuretic hormone levels

Answer 1

The correct option is C Increase in aldosterone

Aldosterone is a hormone secreted by the outer layer of the adrenal gland (the cortex part). Decreased blood volume and interstitial fluid level, resulting in decreased blood pressure, trigger aldosterone secretion. When aldosterone is present in the blood, the epithelial cells of the collecting duct increase reabsorption of$N{a}^{+}$ in the filtrate. Retaining $N{a}^{+}$ raises the osmotic pressure of the blood and reduces water loss from the body. When aldosterone is absent, the same $N{a}^{+}$remains in the filtrate and gets excreted with the urine.