Question

21. Which of the following statements are true in order to decrease glomerular hydraulic pressure?

1. the afferent arteriole will constrict.

2. the afferent arteriole will constrict.

3. the afferent arteriole has no effect on glomerular filtration pressure

4. the afferent arteriole will dilate.

22. An example of reabsorption in the nephron is

1. movement of Na+ from the proximal convoluted tubule into the peritubular capillaries

2. movement of histamine from the peritubular capillaries into the proximal convoluted tubule

3. movement of histamine from the peritubular capillaries into the proximal convoluted tubule

4. movement of K+ from the peritubular capillaries into the distal convoluted tubule

23. the major site of amino acid absorption is the

1. liver

2.stomach

3. large intestine

4. small intestine

24. a negative feedback mechanism in response to reduced intake of salt (NaCl) is likely to include

1. an increase in blood volume due to increase in ADH

2. an increase in renal blood flow due to an increase in water reabsorption

3. an increase in secretion of renin by the juxtaglomerular cells

4. a decrease in secretion of aldosterone and increased Na+ excretion

25. Renin is secreted by

1. speciallized cells in the nephron and converts angiotensinogen into anglotensin 1.

2. lung capillary endothelial cells and converts angiotensin 1 into angiotensin 2.

3. the atria in response to increased stretch and causes a loss of Na+ and water

4. adrenal cortex and promotes K+ secretion in the proximal convoluted tubule.

Answer 1

21. Answer:-(1) the afferent arteriole will constrict Explanation:- the glomerular hydrostatic pressure in the glomerular capillaries is essentially the blood pressure of the glomerulus. The blood comes in the glomerulus from afferent arteriole. As the afferent arteriole constricts, the blood coming into glomerulus decreases due to decrease in size of lumen of afferent arteriole. This decreases the glomerular hydrostatic pressure and hence , the glomerular filteration decreases.

22. Answer:-(1) movement of Na+ from proximal convulated tubule into peritubular capillaries

Explanation:- in renal physiology, reabsorption or tubular reabsorption is the process by which water and solutes is removed by the nephron from tubular fluid and return them into circulating blood. In proximal convulated tubule, most of the sodium is reabsorbed, approx 65-70% . It is also reabsorbed in the thick ascending loop of henle.

23. Answer:-(4) small intestine

Explanation:- most of the amino acids are absorbed in the jejunum of small intestine via co-transport mechanism with Na+ ions.

24. Answer:-(3) an increase in secretion of renin by juxtaglomerular cells

Explanation:- decreased NaCl intake causes decrease in NaCl level in the blood. This decreases the filterate sodium chloride concentration in kidney that will stimulate the macula densa and juxtaglomerular cells of juxtaglomerular apparatus to release renin.

25. Answer:-(1) specialized cells in the nephron and converts angiotensinogen into angiotensin 1

Explanation:- renin is released by specialized cells of nephron called juxtaglomerular cells which is stimulated after activation of macula densa. It converts angiotensinogen into angiotensin 1 which is active form.