Question

Angiotensin II has three very important functions, but is not involved in-

• A. Constriction of the efferent arteriole in the glomerulus.
• B. Constriction of the afferent arteriole in the glomerulus.
• C. It increases sodium and water reabsorption in all portions of the nephron.
• D. Stimulation of aldosterone secretion.

Answer 1

The correct option is B Constriction of the afferent arteriole in the glomerulus.

Angiotensin II causes constriction of the efferent arteriole in the glomerulus. This prevents blood from leaving the glomerular capillary and causes an increase in the hydrostatic pressure inside the glomerulus. This, in turn, causes an increase in GFR. In people with aldosterone deficiency, there is a buildup of potassium in the body and loss of sodium. Patients have characteristic low blood pressure and often crave salty foods. Aldosterone is a hormone secreted by the zona glomerulosa of the adrenal glands in response to angiotensin II stimulation. Angiotensin causes constriction of the efferent arteriole in the glomerulus. This prevents blood from leaving the glomerular capillary and causes an increase in the hydrostatic pressure inside the glomerulus. This, in turn, causes an increase in GFR.