Question

Select the correct match of column I with column II.
Column I Column II
A. Renin I. Facultative water reabsorption
B. Angiotensin II II. Vasoconstrictor
C. Aldosterone III. Released by JG cells
D. Vasopressin IV. Vasodilator
E. ANF V. Reabsorption of sodium and water

• A. A – III; B – II; C – V; D – I; E – IV
• B. A – V; B – IV; C – III; D – Il; E – I
• C. A – III; B – I; C – II; D – IV; E – V
• D. A – III; B – V; C – II; D – I; E – IV

Answer 1

The correct option is A A – III; B – II; C – V; D – I; E – IV

• A fall in glomerular blood flow/glomerular blood pressure/glomerular Filtration Rate (GFR) can activate the Juxtaglomerular cells (JG cells) to release renin. Renin converts angiotensinogen (produced in the liver) in blood to angiotensin I. Subsequently angiotensin I is converted to angiotensin II by the Angiotensin converting enzyme secreted by the endothelial cells in the lungs.
• Angiotensin II, is a powerful vasoconstrictor. It increases the glomerular blood pressure and thereby GFR. Angiotensin II also activates the adrenal cortex to release Aldosterone.
• Aldosterone causes reabsorption of Na+ and water from the distal parts of the tubule. This also results in the increase in the blood pressure and GFR.
• An excessive loss of fluid from the body can activate the osmoreceptors which stimulate the hypothalamus to release antidiuretic hormone (ADH) or vasopressin from the neurohypophysis. ADH facilitates water reabsorption from the distal parts of the tubule, thereby preventing diuresis. ADH is also a vasoconstrictor.
• The increase in blood pressure can cause the release of Atrial Natriuretic Factor (ANF) from the atria of the heart. ANF inhibits sodium reabsorption resulting in dilute urine and decrease in blood pressure causing dilation of blood vessels or vasodilation.