Question

What conditions are responsible for stimulation of juxtaglomerular apparatus?

• A. An increase in blood pressure or blood volume in heart.
• B. An increase in the solute concentration the blood plasma.
• C. A decrease in the solute concentration oil the blood plasma.
• D. Decrease in blood pressure or blood volume in afferent arteriole.

Answer 1

The correct option is D Decrease in blood pressure or blood volume in afferent arteriole.

The juxtaglomerular apparatus is a specialized structure formed by the distal convoluted tubule and the glomerular afferent arteriole. It consists of three cell types: The macula densa, juxtaglomerular cells, and extraglomerular mesangial cells. When the blood pressure or blood volume in afferent arteriole is decreased this condition stimulates the juxtaglomerular cells present in the juxtaglomerular apparatus. The juxtaglomerular cells, derived from smooth muscle cells, of the afferent arteriole, secrete renin when blood pressure in the arteriole falls. Renin increases blood pressure via the renin-angiotensin-aldosterone system. This decrease in blood pressure or blood volume in afferent arteriole is responsible for stimulation of juxtaglomerular apparatus.

So, the correct answer is 'option D'.