Your-Doctor Multiple Choice Questions (MCQ)

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Category: Urology--->Renal Pathophysiology
Page: 1

Question 1#Print Question

Which of the following is CORRECT regarding the nephron?

a. The glomerulus is about 20 μm in diameter and is formed by the invagination of a tuft of capillaries into the dilated, open end of the nephron (Bowman’s capsule)
b. Functionally, the glomerular basement membrane permits the free passage of neutral substances upto 4 nm in diameter and totally excludes those with diameters greater than 8 nm
c. In the distal convoluted tubule, while the predominant principle cells (P) are involved in acid secretion and HCO3 − transport, the intercalated cells (I) are associated with Na+ reabsorption and vasopressin-stimulated water reabsorption
d. The renin-secreting juxtaglomerular cells are situated in that part of the thick ascending limb of the loop of Henle, which traverses close to the afferent arteriole from which the tubule arose
e. In a resting adult, the kidneys receive about 450 mL of blood per minute

Question 2#Print Question

Which of the following is CORRECT regarding GFR? 

a. The best estimate of GFR can be obtained by measuring the rate of clearance of a given substance from the plasma, and inulin clearance is felt to be the best measure of GFR
b. 24-hour creatinine clearance overestimates true GFR by 5%, and thus, as GFR declines, tubular secretion increases in response to increasing creatinine levels may contribute upto 10%–15% of all creatinine levels at GFR levels of 40–80 mL/min. At best, then, the CrCL should be considered the ‘upper limit’ of the true GFR
c. Cockcroft-Gault measures creatinine clearance by the formula: CrCl = {[(140 – age) × (Lean Body Weight in kg)]/[Serum Creatinine (mg/ dL) × 72]} × 1.05 (women)
d. The simplest estimate of GFR is the four-variable equation (PCr, weight, sex and ethnicity), which estimates GFR using the formula: eGFR (mL/min/ 1.73 m) = 186 × (Serum Creatinine [mg/dL])−1.154 × (weight in kg)−0.203 × (0.742 if female) × (1.210 if African American)
e. MDRD, which is used to calculate the eGFR is not validated for use in children, whilst CG formula overestimates CrCl in children due to reabsorption

Question 3#Print Question

Which of the following is TRUE regarding bone mineralisation?

a. The actions of Vitamin D are exerted largely through the liver
b. Vitamin D3 requires two hydroxylations, first in liver and second in the kidney
c. During periods of hypercalcemia, PTH synthesis and secretion are increased while degradation is decreased
d. The renal effects of PTH are to increase active calcium reabsorption at the level of the proximal tubule and decrease phosphate reabsorption mainly in the distal tubule
e. PTH stimulates calcitriol production by decreasing 1α-hydroxylase levels

Question 4#Print Question

Which of the following is TRUE in unilateral ureteric obstruction (UUO)?

a. Renal blood flow (RBF) increases during the first 1 1/2 to 4 hours along with an increase in the ureteric pressure
b. In a second phase lasting between 3 and 5 hours, these pressure parameters remain elevated but RBF begins to rapidly decline
c. A third phase beginning about 5 hours after obstruction is associated with a further drop in RBF and a gradual but small rise in collecting system pressure
d. Infusion of Captopril, an ACE inhibitor attenuates the declines in RBF and GFR in UUO
e. Administration of endothelin antagonists limits the reduction of RBF but increases GFR in rats during and after release of UUO

Question 5#Print Question

Regarding ureteric obstruction (n unilateral ureteric obstruction UUO), which is CORRECT?

a. In UUO, blocking nitric oxide (NO) release contributes to renal vasoconstriction
b. In UUO, Thromboxane A2 (TXA2) administration causes reduction of GFR and rise in RBF
c. In bilateral ureteric obstruction (BUO), there occurs a prolonged increase in RBF that lasts for nearly 4–5 hours
d. In BUO, blood flows from inner to outer cortex
e. Compared to UOO, in BUO accumulation of substances like atrial natriuretic peptide (ANP) leads to preglomerular vasodilation and postglomerular vasoconstriction

Category: Urology--->Renal Pathophysiology
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