vallmo
Forum Junior
Topics: 25
Posts: 37
|
Some more question from mcgill in canada :wink:
Directions:
Choose the single, best answer for each question.
Keep a record of your answers so you can check them against the answer key at the end of the quiz.
1. For those substances that are actively reabsorbed, the maximal amount that can be transported per unit time by the kidney tubules:
A. depends on the maximum rate at which the transport mechanism itself operates
B. is directly related to the plasma concentration of the substance
C. is termed the tubular transport maximum
D. is dependent upon tubular load
E. A and C are correct.
2. If the clearance of Substance X is greater than the clearance of inulin, it is most likely that Substance X is:
A. bound to tubular proteins
B. bound to plasma proteins
C. secreted
D. reabsorbed
E. neither secreted nor reabsorbed
3. Co-transport of glucose:
A. is equivalent to a uniport for glucose
B. will not be affected if the Na+/K+ pump is blocked
C. cannot move glucose against its concentration gradient
D. is equivalent to an antiproton
E. depends on the interaction of Na+ with the glucose carrier
4. The plasma concentration at which a particular substance begins to appear in the urine is the:
A. transport maximum (Tm)
B. fractional excretion
C. filtered load
D. renal threshold
E. titration point
5. The volume of plasma needed each minute to supply a substance at the rate at which it is excreted in the urine is known as the:
A. diffusion constant of the substance
B. clearance of the substance
C. extraction ratio of the substance
D. tubular mass of the substance
E. filtration rate of the substance
6. Renin is produced and secreted from granules located in the:
A. macula densa
B. mesangial cells
C. intercalated cells
D. afferent arteriole
E. interstitial cells
7. About 4 to 6 days after you place a normal person on a low-sodium diet, which of the following will be observed?
A. plasma renin and aldosterone are below normal
B. plasma renin and aldosterone are above normal
C. plasma sodium concentration is below normal
D. plasma sodium concentration is normal
E. B and D are correct.
8. A 100 kg man has a plasma osmolarity of 300 mOsM (milliosmolar). After he drinks 2 liters of water (and before any fluid losses) his steady-state plasma osmolarity would be approximately:
A. 270 mOsM
B. 280 mOsM
C. 290 mOsM
D. 300 mOsM
E. 321 mOsM
9. The normal human glomerular filtration rate (GFR) is approximately (in mL/min):
A. 25
B. 50
C. 125
D. 300
E. 500
10. Which of the following statements is/are correct?
A. Filtration fraction equals glomerular filtration rate divided by renal plasma flow.
B. Tubular maximum secretion has a finite upper limit, though it exhibits a phenomenon analogous to the threshold phenomenon for reabsorption.
C. Clearance ratio equals renal clearance of one substance divided by the clearance of another substance.
D. Effective renal plasma flow is the volume of plasma flow supplied to juxtamedullary nephrons.
E. A, B, and C are correct.
11. The renal "countercurrent" mechanism is dependent upon the anatomic relationship between:
A. the distal tubule and the macula densa
B. the loop of Henle and the macula densa
C. the loop of Henle and the vasa recta
D. the glomerulus and the afferent and efferent arterioles
E. the glomerulus and the proximal tubule
12. If renal perfusion pressure does not change, which of the following changes in afferent and efferent arteriolar resistance would result in an increase in renal blood flow but no change in filtration fraction?
Afferent arteriolar resistance......Efferent arteriolar resistance
A. unchanged ….. decreased
B. decreased ….. unchanged
C. increased ….. unchanged
D. decreased ….. decreased
E. increased ….. increased
Answer Key
1 - E; 2 - C; 3 - E; 4 - A; 5 - E; 6 - A; 7 - D; 8 - D; 9 - C; 10 - E; 11 - C; 12 - D
|
| mani
Forum Guru
Topics: 104
Posts: 1,403
|
a better idea can be that u post 2 or 3 question at once and leave them open for discussion and then give the answers (after 24 hrs at least)
___________________
Sincerity and hard work are the keys to success!
|
| mjl1717
Forum Hero
Topics: 958
Posts: 5,465
|
Yea I agree with Mani {since thats usually how we do it}
___________________
Smell the coffee! "Is That an Osler move??"
|
| vallmo
Forum Junior
Topics: 25
Posts: 37
|
yes, i did that with the heart questions, and agree that it is the best ways, but I have found these questions on the internet, and I found it easier to just copy and paste all at one time. (Im in a library and cant save things on the computer).
Also, the answers are at the end of the document, so I think its pretty easy to avoid looking at them.
|
| meghana jadhav
Forum Elite
Topics: 80
Posts: 304
|
6. Renin is produced and secreted from granules located in the:
A. macula densa
B. mesangial cells
C. intercalated cells
D. afferent arteriole
E. interstitial cells
i dont agree with this ans 6 - A;...the ans is cells of afferent atrerioles
___________________
megha
|
| vrach
Forum Junior
Topics: 3
Posts: 79
|
The answers given for some of the Q's seem to be wrong
I feel that the answers should be:
Q4. Renal threshold (D)- pretty sure about this one.
Q5. The answer choice I was looking for is not given - Renal Plasma Flow
Q6. Totally agree with Meghana
Q7. Why can't the answer be E. ?
|
| mjl1717
Forum Hero
Topics: 958
Posts: 5,465
|
Renin is secreted by the juxtglomerular apparatus:
The jg apparatus is composed of 3 structure:
1) granular or juxtaglomerular cells
2)macula densa
3) connective tissue cells
But the granular cells are differentiated smooth muscle in the afferent
arteriole where the arterioles junction with the glomeruli. Granular cells secrete renin. The macula densa is the specialized portion of the tubule that marks the transition from the acending loop of Henle to the distal tubule. This nephron segment always touches the afferent arteriole and glomerulus from its own nephron of origin , and the macula densa, themselves are in intimaate contact withe granular cells .Evidence suggest that the macula densa contributes to the control of renin secretion. Whew!
Feedback Please
Ref.--Renal Physiology by Arthur Vander.
___________________
Smell the coffee! "Is That an Osler move??"
|
| vallmo
Forum Junior
Topics: 25
Posts: 37
|
I havent actually read the questions yet before i posted it, and at a quick glance at 6, I also think that it should be mac. densa.
But the quizz is taken fromhttp://sprojects.mmi.mcgill.ca/nephrology/resources/
, and seems to be a very reliable resource, so I wonder if it could be more difficult than it seems? The q is asking about where renin is secreted AND produced, and perhaps renin isnt produced there, but only storaged? I dont have any books with me, but I will see if I find anything in the library on monday.
|
|
| |
| | | | | | | | |
