Question

A fall in glomerular filtration rate (GFR) activates:

• A. Juxtaglomerular cells to release renin
• B. Adrenal cortex to release aldosterone
• C. Adrenal medulla to release adrenaline
• D. Posterior pituitary to release vasopressin

Answer 1

The correct option is A Juxtaglomerular cells to release renin

A fall in glomerular filteration rate (GFR) activates juxta glomerlular of kidney cells to release renin, which activates the renin-angiotensin -aldosterone system (RAAS), which is a signaling pathway responsible for regulating blood pressure. A hormone released by lungs called ACE (angiotensin converting hormone) converts angiotensin I to angiotensin II which is a powerful vasoconstrictor and also increases the reabsorption of salts through DCT, which leads to increase in blood pressure. As the blood pressure is regulated the GFR is also regulated.