Question

ADH carries out following functions except
A) Increases blood pressure
B) Increases glomerular filtration rate
C) Increases permeability for water in DTC
D) Increases $Na^+$ excretion

Answer 1

Hint: ADH is an antidiuretic hormone. It is also called vasopressin. It is secreted by the pituitary gland. To regulate the amount of water in the blood the main function is of ADH. The blood pressure is controlled by acting on kidneys. This increases water reabsorption.

Complete Answer:
Let’s discuss the given options and find the correct answer.

A) Increases blood pressure: ADH main function is to regulate the amount of water in the blood. The blood pressure has been controlled by acting on kidneys. Hence, This option is incorrect.
B) Increases glomerular filtration rate: Since, ADH main function is to regulate the amount of water in the blood. By acting on kidneys it controls the blood pressure. This option is incorrect.
C) Increases permeability for water in DTC: Since, It increases the permeability of water in distal convoluted tubules. This increases water reabsorption. This option is incorrect.
D) Increases $Na^+$ excretion: Sodium absorption in kidneys is controlled by aldosterone secreted from the adrenal cortex. This increases water reabsorption. It also increases the glomerular filtration rate by increasing blood pressure.

Hence, The option D: Increasing $Na^+$ excretion is the correct answer.

Note: ADH (Antidiuretic hormone) or Vasopressin is secreted from the posterior part of pituitary gland i.e. neurohypophysis. This results in a decreased rate of urine production.