Question

1. The afferent arteriole supplies blood to:

1. Renal artery
2. Glomerular capillaries
3. Efferent arterioles
4. Bowman’s capsule

2. After filtration of blood in renal corpuscle, urine flow in nephron is as follows:

1. Proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct
2. Loop of Henle, proximal convoluted tubule, collecting duct, distal convoluted tubule
3. Proximal convoluted tubule, loop of Henle, collecting duct, distal convoluted tubule
4. Loop of Henle, peritubular duct, distal convoluted tubule, collecting duct

3. As a result of renin-angiotensin-aldosterone system:

1. Aldosterone is secreted from pituitary gland
2. Arteriolar vasoconstriction occurs and blood pressure increases
3. ADH is produced by adrenal cortex
4. Arteriolar vasodilation occurs and blood pressure decreases

4. Which of the following increases the rate of glomerular filtration?

1. Decrease in blood pressure
2. Increase in blood pressure
3. Vasoconstriction of afferent arteriole
4. Vasodilation of efferent arteriole

5. The glomerular capillaries of nephron are associated with:

1. pH adjustment
2. Osmosis of water
3. Filtration
4. Reabsorption of nutrients

Answer 1

1. Option 'b' (Glomerular capillaries) is correct

Justification: The afferent arteriole supplies blood to the capillaries of glomerulus. Blood enters glomerular capillaries by afferent arteriole and it leaves by efferent arteriole.

Justification for incorrect options:

• Option 'a' is incorrect because renal artery supplies blood to the kidney but, afferent arteriole will not supply blood to the renal artery. So, this option is incorrect.
• Option 'c' is incorrect because afferent arteriole supplies blood to the glomerular capillaries but NOT to the efferent arteriole, and the blood leaves from the efferent arteriole. So, this option is incorrect.
• Option 'd' is incorrect because bowman's capsule receives blood from the arteriole of renal artery but NOT from the afferent arteriole. So, this option is incorrect.

Hence, afferent arteriole supplies blood to the option 'b' (glomerular capillaries).

2. Option 'a' (Proximal convoluted tubule, Loop of Henle, Distal convoluted tubule, Collecting duct) is correct

Justification: After the filtration of blood in the renal corpuscle, urine flows through glomerulus and bowman's capsule into the "proximal convoluted tubule" and the descending "loop of Henle". From the descending loop of Henle, it flows through the ascending loop of Henle into the "distal convoluted tubule" and finally, it reaches the "collecting duct". So, option 'a' is the correct sequence of the flow of urine in nephron.

Justification for incorrect options:

• Option 'b' is incorrect because after the filtration of blood, urine flows into the proximal convoluted tubule but NOT into the loop of Henle.
• Option 'c' is incorrect because after the flow of urine into the loop of Henle, it enters distal convoluted tubule but NOT the collecting duct.
• Option 'd' is incorrect because urine after filtration in renal corpuscle, flows into proximal convoluted tubule but NOT into the peritubular duct. So, this option is incorrect.

3. Option 'b' (Arteriolar vasoconstriction occurs and blood pressure increases) is correct

Justification: In the renin-angiotensin-aldosterone system (RAAS), arteriolar vasoconstriction takes place by Angiotensin-II as a stimulatory signal and this causes increase in blood pressure.

Justification for incorrect options:

• Option 'a' is incorrect because Aldosterone in RAAS is secreted from the adrenal gland cortex but NOT from the pituitary gland.
• Option 'c' is incorrect because anti-diuretic hormone (ADH) in RAAS is secreted by the pituitary gland but NOT by the adrenal cortex.
• Option 'd' is incorrect because in RAAS, vasoconstriction of arterioles takes place but NOT the vasodilation and the arteriolar vasoconstriction increases blood pressure.

4. Option 'b' (Increase in blood pressure) is correct

Justification: The rate of glomerular filtration is increased by the increase in blood pressure, as the increased pressure increases the delivery of fluids and sodium to the distal nephron.

Justification for incorrect options:

• Option 'a' is incorrect because rate of glomerular filtration is increased by an increase in blood pressure but NOT by decrease in blood pressure.
• Option 'c' is incorrect because rate of glomerular filtration is increased by the vasoconstriction of efferent arteriole but NOT afferent arteriole.
• Option 'd' is incorrect because rate of glomerular filtration is increased by vasodilation of afferent arteriole but NOT efferent arteriole.

5. Option 'c' (filtration) is correct

Justification: The glomerular capillaries of nephron are associated with the filtration because their main function is to filter the blood to get glomerular filtrate.

Justification for incorrect options:

• Option 'a' is incorrect because pH adjustment in the nephron is done by the protons and buffers in the kidney but NOT by the glomerular capillaries.
• Option 'b' is incorrect because osmosis of water is carried out by the loop of Henle of nephron but NOT by the glomerular capillaries.
• Option 'd' is incorrect because the reabsorption of nutrients in nephron is carried out by the proximal convoluted tubule (PCT) but NOT by the glomerular capillaries.

So, option 'c' (Filtration) is carried out only by the glomerular capillaries.

Thank you!