REVISION QUESTION SERIES TWO
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1. Which of the following factors would decrease the GFR?
|
a. |
a fall in plasma protein concentration. |
|
b. |
an obstruction such as a kidney stone in the tubular system, which increases Bowman's capsule hydrostatic pressure. |
|
c. |
vasodilation of the afferent arterioles. |
|
d. |
Two of these answers. |
|
e. |
All of these answers. |
____ 2. The macula densa
|
a. |
consists of specialized tubular cells in the juxtaglomerular apparatus. |
|
b. |
consists of specialized arteriolar smooth-muscle cells in the juxtaglomerular apparatus. |
|
c. |
secretes renin. |
|
d. |
Both (a) and (c) above. |
|
e. |
Both (b) and (c) above. |
____ 3. Which of the following is involved in autoregulation of the GFR?
|
a. |
a myogenic mechanism in which the afferent arteriole automatically constricts when it is stretched |
|
b. |
a tubulo-glomerular feedback mechanism in which vasoactive chemicals released from the juxtaglomerular apparatus bring about afferent arteriolar vasoconstriction |
|
c. |
sympathetically induced vasoconstriction of the afferent arterioles |
|
d. |
Both (a) and (b) above. |
|
e. |
All of these answers. |
____ 4. Changes in the glomerular filtration rates are accomplished through
|
a. |
autoregulation. |
|
b. |
myogenic activity. |
|
c. |
vasoactive responses in the afferent arteriole. |
|
d. |
Both (a) and (b) above. |
|
e. |
All of these answers. |
____ 5. Afferent arteriolar vasoconstriction __________ blood flow into the glomerulus, which causes the glomerular-capillary blood pressure to __________, leading to a(n) __________ in the net filtration pressure and a resultant __________ in the GFR.
|
a. |
increases, increase, increase, increase |
|
b. |
decreases, decrease, decrease, decrease |
|
c. |
increases, increase, decrease, decrease |
|
d. |
decreases, decrease, increase, increase |
|
e. |
None of these answers. |
____ 6. The myogenic mechanism
|
a. |
causes the afferent arteriole to constrict when blood pressure is too high. |
|
b. |
may result from stretching of vascular smooth muscle. |
|
c. |
Is an autoregulatory mechanism. |
|
d. |
Both (a) and (b) above. |
|
e. |
All of these answers. |
____ 7. Stimulation of the macula densa cells
|
a. |
results in vasodilation of the afferent arteriole. |
|
b. |
results in vasoconstriction of the afferent arteriole. |
|
c. |
increases GFR. |
|
d. |
Both (a) and (b) above. |
|
e. |
Both (a) and (c) above. |
____ 8. Extrinsic control of the GFR
|
a. |
is mediated by sympathetic nervous system input to the afferent arterioles. |
|
b. |
is aimed at the regulation of arterial blood pressure. |
|
c. |
does not require a special mechanism but occurs as part of the baroreceptor reflex. |
|
d. |
Both (a) and (b) above. |
|
e. |
All of these answers. |
____ 9. When arterial blood pressure is elevated above normal, which of the following compensatory changes in renal function occur as a result of the baroreceptor reflex?
|
a. |
afferent arteriolar vasoconstriction |
|
b. |
afferent arteriolar vasodilation |
|
c. |
reduction in GFR |
|
d. |
Both (a) and (c) above. |
|
e. |
Both (b) and (c) above. |
____ 10. Tubular reabsorption
|
a. |
refers to the movement of a substance from the peritubular capillary blood into the tubular fluid. |
|
b. |
occurs by either active or passive transport. |
|
c. |
involves the process of transepithelial transport. |
|
d. |
Both (b) and (c) above. |
|
e. |
All of these answers. |
____ 11. Which of the following statements regarding tubular reabsorption is incorrect? Tubular reabsorption
|
a. |
refers to the movement of a substance from the tubular fluid to the peritubular capillary blood. |
|
b. |
is important for the conservation of substances important to the body, such as Na+, Cl-, glucose, and amino acids. |
|
c. |
can occur by active or passive transport mechanisms. |
|
d. |
involves the process of transepithelial transport. |
|
e. |
takes place only in the proximal tubule. |
____ 12. Tubular reabsorption
|
a. |
involves the movement of substances from the peritubular capillaries into the tubular fluid. |
|
b. |
involves the movement of substances from the tubular fluid into the peritubular capillaries. |
|
c. |
is considered to be active if any one of the five steps of transepithelial transport is active. |
|
d. |
Both (a) and (c) above. |
|
e. |
Both (b) and (c) above. |
____ 13. Tubular reabsorption involves
|
a. |
active transport. |
|
b. |
cotransport. |
|
c. |
facilitated diffusion. |
|
d. |
countertransport. |
|
e. |
All of these answers. |
____ 14. Which of the following is not a step in transepithelial transport?
|
a. |
movement of the substance through the cytosol of the tubular cell |
|
b. |
movement of the substance across the glomerular capillary wall |
|
c. |
movement of the substance across the luminal membrane of the tubular cell |
|
d. |
movement of the substance through the interstitial fluid |
|
e. |
movement of the substance across the basolateral membrane of the tubular cell |
____ 15. The Na+-K+ ATPase transport system that plays a pivotal role in much of tubular reabsorption is located in the
|
a. |
luminal membrane of tubular cells. |
|
b. |
basolateral membrane of tubular cells. |
|
c. |
podocytes. |
|
d. |
glomerular capillary membrane. |
|
e. |
basement membrane. |
____ 16. Which is reabsorbed by the proximal convoluted tubule?
|
a. |
sodium. |
|
b. |
amino acids. |
|
c. |
glucose. |
|
d. |
All of these answers. |
|
e. |
None of these answers. |
____ 17. Into which structure does most reabsorption occur?
|
a. |
proximal convoluted tubule. |
|
b. |
glomerulus. |
|
c. |
distal convoluted tubule. |
|
d. |
loop of Henle. |
|
e. |
None of these answers. |
____ 18. Glucose is not normally found in the urine because:
|
a. |
does not get filtered out of glomerulus. |
|
b. |
it is not found in the blood. |
|
c. |
it is reabsorbed by renal tubule cells usually. |
|
d. |
it is kept in the blood. |
|
e. |
None of these answers. |
____ 19. The proximal tubule
|
a. |
reabsorbs about 65% of the filtered water. |
|
b. |
is not the site of action of renin. |
|
c. |
is the location where glucose is reabsorbed. |
|
d. |
reabsorbs about 65% of the filtered water and is the location where glucose is reabsorbed. |
|
e. |
All of these answers. |
____ 20. Tubular maximum (Tm)
|
a. |
is the maximum amount of a substance that the tubular cells can actively transport within a given time period. |
|
b. |
is the maximum rate at which a substance is filtered at the glomerulus. |
|
c. |
occurs when the membrane carrier becomes saturated. |
|
d. |
Both (a) and (c) above. |
|
e. |
Both (b) and (c) above. |
____ 21. Tm is the maximum
|
a. |
rate of glomerular filtration. |
|
b. |
rate a substance can be reabsorbed because of saturation of the carrier molecule. |
|
c. |
rate of urine excretion. |
|
d. |
rate a substance can be cleared from the blood. |
|
e. |
percentage of renal blood flow that can be converted to filtrate. |
____ 22. The renal threshold is the
|
a. |
maximum amount of a particular substance that can be excreted in the urine per unit of time. |
|
b. |
maximum amount of a particular substance that the tubular cells are capable of actively reabsorbing per unit of time. |
|
c. |
plasma concentration of a particular substance at which its Tm is reached and the substance first appears in the urine. |
|
d. |
maximum amount of waste products that can be concentrated in the urine per unit of time. |
|
e. |
maximum amount of water that can be osmotically absorbed across the tubules per unit of time. |
____ 23. Which of the following plasma constituents is not regulated by the kidneys?
|
a. |
glucose |
|
b. |
Na+ |
|
c. |
H+ |
|
d. |
phosphate |
|
e. |
water |
____ 24. Reabsorption of chloride
|
a. |
is active. |
|
b. |
is passive. |
|
c. |
is dependent on the amount of sodium reabsorbed. |
|
d. |
Both (a) and (b) above. |
|
e. |
Both (b) and (c) above. |
____ 25. Select the major waste product of nitrogen metabolism.
|
a. |
plasma proteins. |
|
b. |
urea. |
|
c. |
glucose. |
|
d. |
PO4. |
|
e. |
amino acids. |
____ 26. Given the following data for substance X (GFR = 125 ml/min, Tm = 125 mg/min, at a plasma concentration of 200 mg/100 ml), how much of substance X is filtered, reabsorbed, and excreted?
|
a. |
200 mg/min filtered, 125 mg/min reabsorbed, 75 mg/min excreted |
|
b. |
250 mg/min filtered, 125 mg/min reabsorbed, 125 mg/min excreted |
|
c. |
125 mg/min filtered, 125 mg/min reabsorbed, 0 mg/min excreted |
|
d. |
250 mg/min filtered, 200 mg/min reabsorbed, 50 mg/min excreted |
|
e. |
None of these answers. |
____ 27. The juxtaglomerular apparatus
|
a. |
secretes renin in response to sodium depletion or plasma volume reduction. |
|
b. |
is a thickened region of specialized cells at a point where the distal tubule comes into intimate contact with the afferent and efferent arterioles of the same nephron. |
|
c. |
is where reabsorption of sodium occurs. |
|
d. |
Both (a) and (b) above. |
|
e. |
All of these answers. |
____ 28. The normal glucose concentration in the plasma is about________ mg per 100 ml.
|
a. |
30 |
|
b. |
60 |
|
c. |
100 |
|
d. |
180 |
|
e. |
250 |
____ 29. Which statement regarding sodium reabsorption is not accurate?
|
a. |
it plays a role in glucose, amino acid, and urea reabsorption in the proximal tubule. |
|
b. |
it is under hormonal control in the distal tubule. |
|
c. |
in the loop of Henle, it contributes to the formation of concentrated urine. |
|
d. |
approximately 0.5% of sodium is reabsorbed on a daily basis. |
|
e. |
aldosterone is a key hormone involved in facultative reabsorption. |
____ 30. The juxtaglomerular apparatus
|
a. |
is a combination of specialized tubular and vascular cells at a point where the beginning of the distal tubule comes into intimate contact with the afferent and efferent arterioles of the same nephron. |
|
b. |
secretes aldosterone. |
|
c. |
secretes renin. |
|
d. |
Both (a) and (b) above. |
|
e. |
Both (a) and (c) above. |