Question

acts on venous and arterial smooth muscles, kidneys and the pituitary gland in order to regulate blood pressure.

• A. Renin
• B. Angiotensinogen
• C. Angiotensin I
• D. Angiotensin II

Answer 1

The correct option is D Angiotensin II

Renin converts angiotensinogen in blood to angiotensin I and further to angiotensin II. Angiotensin II, being a powerful vasoconstrictor, increases the glomerular blood pressure and thereby GFR. Angiotensin II also activates the adrenal cortex to release aldosterone.

Aldosterone causes reabsorption of ${\mathrm{Na}}^{+}$ and water from the distal parts of the tubule. This also leads to an increase in blood pressure and GFR. This complex mechanism is generally known as the Renin-Angiotensin mechanism.

Acts on venous and arterial smooth muscles making them constrict and thereby increases blood pressure. Also acts on pitutary gland to produce ADH which helps in the control of blood pressure.