Question

Juxtaglomerular cells secrete A when there is a fall in B concentration. Choose the correct pair labelled as A and B.

• A. A : Renin, B : Chloride
• B. A : Carbonic anhydrase, B : Sodium
• C. A : ATPase, B : Potassium
• D. A : Renin, B : Sodium chloride

Answer 1

The correct option is D A : Renin, B : Sodium chloride

Juxtaglomerular cells are the specialized smooth muscle cells present in the walls of the afferent arterioles that go to the glomerulus. Their function is to produce an enzyme called renin when the osmolarity of blood changes. Renin converts angiotensin secreted by the liver into angiotensin$I$. This is later converted into angiotensin$II$ by an enzyme released by lungs. Angiotensin$II$ acts on adrenal glands to stimulate the release of aldosterone. Aldosterone helps in reabsorption of na+ and water from distal convoluted tubule and the concentration of Na${}^{+}$ ions decreases in the filtrate.

So juxtaglomerular cells secrete renin when then is fall in sodium chloride concentration

So, the correct option is D.