Wednesday, March 14, 2018

Renal system-Physiology MCQs


RENAL SYSTEM
1. Vasa recta is formed by
A) The cortical nephron’s peritubular capillaries
B) The juxta medullary nephron’s peritubular capillaries
C) The distal tubule
D) The proximal tubule
Ans: B
2. How many % of nephrons in humans are cortical nephrons?
A) 20%
B) 30%
C) 50%
D) 80%
Ans: 80%
3. Counter current mechanism takes place in
A) Cortical nephrons
B) Renal pelvis
C) Juxta medulary nephrons
D) None of the above
Ans: C
4. Which of the following parts of tubular segment is always impermeable to water?
A) Descending limb of loop of henle
B) Ascending limb of loop of henle
C) Collecting duct
D) Proximal convoluted tubule
Ans: B
5. Which of the following substances is actively reabsorbed in the proximal tubule and actively secreted in the distal & collecting tubule?
A) Na+
B) H+
C)K+
D) Glucose
Ans: C
6. If ascending limb of loop of Henle is permeable to water, what would be the minimum/maximum urine Osmolarity the person could produce?
A) 300/1200
B) 1200/1200
C) 300/300
D) 100/100
Ans: C
7. Bowman’s capsule colloidal osmotic pressure is
A) 32
B) 60
C) 18
D) 0
Ans: D
8. The normal glomerular capillary colloid osmotic pressure is
A) 32
B) 60
C) 18
D) 0
Ans: A
9. Glomerular capillary pressure is
A) 32
B) 60
C) 18
D) 0
Ans: B
Explanation: Compared with other capillaries [17 mmHg], the glomerular pressure is very high [60 mmHg] and favours filtration.
10. Renal vascular resistance resides mainly in
A) Renal A & Glomerular capillaries
B) Interlobar, Afferent & Efferent arterioles
C) Glomerular capillaries & Renal vein
D) Renal A & Arcuate Vein
Ans: B
Explanation: Increase in resistance decreases RBF, whereas ↓ in resistance ↑ RBF.
11. Which of the following substances causes ↑ GFR?
A) Epinephrine
B) AngiotensinII
C) Prostaglandins
D) Norepinephrine
Ans: C
12. The flat segment in the graph of the cystometrogram is a manifestation of
A)  Fick’s law
B) Boyel’s law
C) Law of Laplace
D) Ohm’s law
Ans: C
13. In the presence of ADH, the greatest fraction of filtered water is absorbed in the
A) Cortical collecting duct
B) Distal tubule
C)Henle’s loop
D) Proximal tubule
Ans: D
14. The major site of renal gluconeogenesis is
A) Proximal tubule
B) Loop of Henle
C) Distal tubule
D) Collecting tubule
Ans: A
Explanation: Renal gluconeogenesis occurs only in unusual circumstances like prolonged starvation& chronic respiratory acidosis.
15. Renal O2 consumption is approximately
A) 6ml/100 g tissue/mt
B) 20ml/100 g tissue/mt
C) 25ml/100 g tissue/mt
D) 30ml/100 g tissue/mt
Ans: A
16. Darrow-Yannet diagram
A) Represents counter-current mechanism
B) Represents cystometrogram
C) Simplify the clinical analysis of fluid balance
D) Represents auto regulation of blood flow
Ans: C
17. Afferent arteriole constriction
A) ↓ both RPF&GFR
B) ↑ both RPF&GFR
C) ↓RPF&↑GFR
D) ↑RPF&↓GFR
Ans: A
18. Afferent arteriole dilatation
A) ↓ both RPF&GFR
B) ↑ both RPF&GFR
C) ↓RPF&↑GFR
D) ↑RPF&↓GFR
Ans: B
19. Constriction of Efferent arteriole
A) ↓ both RPF&GFR
B) ↑ both RPF&GFR
C) ↓RPF&↑GFR
D) ↑RPF&↓GFR
Ans: C
20. Dilatation of Efferent arteriole
A) ↓ both RPF&GFR
B) ↑ both RPF&GFR
C) ↓RPF&↑GFR
D) ↑RPF&↓GFR
Ans: D
21. Juxta glomerular cells are
A) Baroreceptors
B) Chemoreceptors
C)Telereceptors
D) Light receptors
Ans: A
22. Macula densa cells are
A) Baroreceptors
B) Chemoreceptors
C) Telereceptors
D) Light receptors
Ans: B
23. Fluid in the early distal tubular segment is
A) Iso tonic
B) Hypo osmotic
C) Hyper osmotic
D) Regardless of whether ADH is present or not
Ans: B
24. Obligatory urine volume is
A) 0.5 L/day
B) 1L/day
C) 1.5L/day
D) 50 ml/day
Ans: A
25. The active pump in the thick ascending limb on the loop of Henle establishes the following concentration gradient between tubular fluid and interstitial fluid.
A) 500 mOsm/L
B) 400 mOsm/L
C) 300 mOsm/L
D) 200 mOsm/L
Ans: D
26. Urea transporter UT-A1 is activated by
A) ADH
B) AngiotensinII
C) ↑ blood volume
D) ↑ blood pressure
Ans: A
27. Plasma Osmolarity can be approximately calculated as
A) 2.1 ×plasma Na+ conc.
B) 2.1 ×plasma K+ conc.
C) 2.1 ×plasma Cl conc.
D) 2.1 ×plasma Hco3 conc.
Ans: A
28. The most important Extracellular buffer is
A) Protein
B) Hco3
C) Phosphate
D) Ammonia
Ans: B
29. Total acid production in the body is derived from
A) Oxidative metabolism
B) Protein catabolism
C) Triglyceride catabolism
D) Lipoprotein metabolism
Ans: A
Explanation: The greatest source of H+ is the CO2 produced during oxidative metabolism. About 13,000 mmol of Co2 daily or 13,000 mEq of H /day
30. The major fraction of 80% of the total Co2 in the bone is in the form of
A) Carbonic acid
B) Bicarbonate
C) Carbonate
D) Hb
Ans: C
Explanation: about 2/3 rds of total Co2 is in the form of carbonates combined with Na, Ca & other cations in bone crystals. The remaining 1/3 rd consists of Hco3.The total bone carbonate is 50 times the amount of Hco3 found in the ICF & ECF together.
31. H+ secretion in the proximal tubule occurs primarily by
A) Primary active transport
B) Secondary active transport
C) Facilitated diffusion
D) Simple diffusion
Ans: B
32. H+ secretion in the late distal tubule occurs by
A) Primary active transport
B) Secondary active transport
C) Facilitated diffusion
D) Simple diffusion
Ans: A
33. Which of the following would be expected to cause ↑H secretion & Hco3 Reabsorption?
A) ↓ AngiotensinII
B) ↑ ECF volume
C) ↓ Aldosterone
D) ↑ Pco2
Ans: D
34. In the renal regulation of acid base balance, new Hco3 is formed by
A) Hco3 buffer system
B) Phosphate buffer system
C) Ammonia buffer system
D) B& C
Ans: D
True/false
35.In ECF the total concentration of cations exceeds that of anions.
Ans: false-these must be equal.Anion gap is not true deficit.
36.The acid buffering power of venous blood is greater than arterial blood.
 Ans: True.Hco3 is slightly higher in venous blood. deoxy Hb is a betterbuffer.
38.In arterial blood metabolic alkalosis may be caused by tissue anoxia.
Ans:false.may cause metabolic acidosis through anaerobic metabolism
39.Micturition is a sacral spinal reflex.
Ans:true
40.If systemic blood pressure falls by 50% GFR drops to 0.
Ans:true.sympathetically driven constriction of efferent arteriole.











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