Block 6 Renal Physio Dr Shams W Xpl

26 Questions | By Chachelly | Updated: Mar 21, 2022 | Attempts: 861

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Block 6 Renal Physio Dr Shams W Xpl - Quiz

The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, control levels of electrolytes and metabolites, and regulate blood Ph. This is made possible through the various parts of the system. Take the Block 6 renal physio dr shams w xpl and see how well you know them.

Questions and Answers

1.

In which of the following parts of the renal tubule does the lowest concentration of potassium in the tubular fluid occur?
- A.
  
  Proximal tubule
- B.
  
  Thick ascending limb of Henle's loop
- C.
  
  Collecting duct
- D.
  
  Distal tubule
2.

In which of the following parts of the renal tubule does the lowest concentration of sodium (Na+) in the tubular fluid occur?
- A.
  
  Proximal tubule
- B.
  
  Thick ascending limb of Henle's loop
- C.
  
  Collecting duct
- D.
  
  Distal tubule
3.

Which of the following parts of the renal tubule is associated with regulated changes in water permeability?
- A.
  
  Proximal tubule
- B.
  
  Thick ascending limb of Henle's loop
- C.
  
  Collecting duct
- D.
  
  Distal tubule
4.

Which of the following parts of the renal tubule is associated with the highest permeability to urea?
- A.
  
  Proximal tubule
- B.
  
  Thick ascending limb of Henle's loop
- C.
  
  Collecting duct
- D.
  
  Distal tubule
5.

Which of the following parts of the renal tubule is associated with most potassium reabsorption?
- A.
  
  Proximal tubule
- B.
  
  Thick ascending limb of Henle's loop
- C.
  
  Collecting duct
- D.
  
  Distal tubule
6.

Which of the following parts of the renal tubule is associated with most sodium reabsorption?
- A.
  
  Proximal tubule
- B.
  
  Thick ascending limb of Henle's loop
- C.
  
  Collecting duct
- D.
  
  Distal tubule
7.

A male volunteer aged 48 years and weight 154 pounds (70 kg) is given an intravenous infusion of PAH (para‐amino‐ hippuric acid) and inulin that achieved constant plasma levels of both. 100 mL of urine was collected over a period of 2 hours. His hematocrit was 40%. His laboratory values for urine and plasma are shown in the table. Which of the following rates of glomerular filtration (GFR) most closely approximate his true rate of filtration? Plasma conc [mmol/L] Urine conc [mmol/L] PAH 0.05 30 Inulin 0.05 6
- A.
  
  GFR = 90 mL/min
- B.
  
  GFR = 50 mL/min
- C.
  
  GFR = 100 mL/min
- D.
  
  GFR = 500 mL/min
8.

In the same volunteer described in the last question, with a 100 mL of urine being collected over a period of 2 hours and the lab values presented in the table ‐ what is the percentage of filtered water being reabsorbed? Plasma conc [mmol/L] Urine conc [mmol/L] PAH 0.05 30 Inulin 0.05 6
- A.
  
  90%
- B.
  
  95%
- C.
  
  99%
- D.
  
  99.2%
- E.
  
  99.5%
9.

A 48‐year‐old woman presents to her doctor with persistent cough. She reports feeling constantly tired and weak and complains of loss of appetite. She reveals a life‐long smoking habit of 1 ‐ 2 packs per week. Her blood pressure is at the high end of normal, other vital signs are normal, but a chest X‐ray reveals a lower left lobe mass. Her laboratory results show the following results (normal ranges in parentheses): Plasma Na+ = 125 mEq/L (136 ‐ 145 mEq/L) Plasma K+ = 3.9 mEq/L (3.5 ‐ 5.0 mEq/L) Plasma HCO3‐ = 24 mEq/L (22‐28 mEq/L) Plasma osmolality = 253 mOsmol /Kg H2O (275 ‐ 295 mOsmol /Kg H2O) Urine Na+ = 48 (>25 mEq/L) Urine osmolality = 280 mOsm/Kg H2O ( 50 ‐ 1400 mOsmol/Kg H2O) What hormonal mechanism is most likely responsible for her abnormal laboratory values?
- A.
  
  Elevation of adrenal cortical cAMP levels leading to increased production and secretion of corticosteroids
- B.
  
  Elevated hypothalamic cAMP levels resulting in inhibition of the thirst mechanism
- C.
  
  Activation of both V2 receptors causing vasoconstriction and V1 receptors leading to urine concentration
- D.
  
  Activation of V2 receptors leading to increased water absorption in the collecting duct and activation of V1 receptors causing decreased peripheral resistance
- E.
  
  Activation of V2 receptors leading to increased water absorption in the collecting duct and activation of V1 receptors causing increased peripheral resistance
10.

Calcium undergoes absorption in more than one part of the nephron. What is the primary driving force for its absorption in the thick ascending limb of Henle's loop?
- A.
  
  Activity of the loop diuretic ‐ sensitive Na+‐K+‐2Cl‐ triporter, NKCC2
- B.
  
  Basal action of parathyroid hormone PTH
- C.
  
  The maintenance of a lumen negative electrical potential difference
- D.
  
  Na+/Ca+ exchange
- E.
  
  Activity of the thiazide‐sensitive Na+ ‐ Cl‐ cotransporter NCCT
11.

In a laboratory study, a number of novel drug compounds are being investigated for their cardiovascular actions. One compound is identified that when injected intravenously causes increased renal blood flow. Through which of the following mechanisms is the drug likely to be acting?
- A.
  
  Stimulation of only alpha adrenergic receptors in the afferent arteriole
- B.
  
  Stimulation of only angiotensin II receptors in the afferent arteriole
- C.
  
  Stimulation of angiotensin II receptors and activation of stretch activated Ca2+ channels in vascular smooth muscle
- D.
  
  Stimulation of both renal alpha adrenergic receptors as well as angiotensin II receptors
- E.
  
  Stimulation of renal dopamine and bradykinin receptors
12.

Diuretics are drugs that are used to increase urine flow. Their effectiveness and effects of individual ion excretion depends on their renal site of action. Which of the following types of diuretic can cause a reduction in renal excretion of Ca2+ and therefore may be effective in reducing renal stone formation?
- A.
  
  A carbonic anhydrase inhibitor
- B.
  
  An inhibitor of ENaC
- C.
  
  An inhibitor of Na+‐K+‐2Cl‐ cotransport (NKCC2)
- D.
  
  An inhibitor of Na+‐Cl‐ cotransport (NCCT)
- E.
  
  An inhibitor of the mineralocorticoid receptor
13.

A group of healthy volunteers embark on a study in which their dietary intake of sodium chloride is doubled over a period of one month. At the end of this period the average blood pressure of the group was found to be raised when compared to the control period before they started increasing their salt intake. What is the most likely physiological response to the raised salt intake?
- A.
  
  Decreased release of Atrial Natriuretic Peptide (ANP) and dilation of afferent arterioles
- B.
  
  Afferent arteriolar dilation caused by decreased sympathetic nerve activity
- C.
  
  Increased ANP release and constriction of afferent arterioles
- D.
  
  Increased release of aldosterone
- E.
  
  Increased plasma oncotic pressure
14.

A 70‐year‐old male recovering from hip‐replacement surgery is given an NSAID for pain management. 48 hours later, his urine production has decreased markedly and his serum blood urea nitrogen and creatinine levels have risen to 64 mg/dL and 2.5 mg/dL respectively. Through which of the following mechanisms is the NSAID causing acute renal failure?
- A.
  
  Inhibition of renal prostaglandin production causing afferent arteriolar constriction
- B.
  
  Inhibition of renal prostaglandin production causing efferent arteriolar constriction
- C.
  
  Inhibition of renal prostaglandin production causing dilation of efferent arterioles
- D.
  
  Stimulation of renal prostaglandin production and reflex arteriolar vasoconstriction
- E.
  
  Stimulation of renal prostaglandin production and reflex arteriolar dilatation
15.

As part of an annual health check on a 48‐year‐old woman, a 24‐hour urine test revealed an albumin excretion of 100 mg (normally <20 mg). Which cell type is likely to be damaged or is malfunctioning in this individual.
- A.
  
  Glomerular endothelial cell
- B.
  
  Juxtaglomerular cell
- C.
  
  Mesangial cell
- D.
  
  Podocyte
16.

A 38‐year‐old male complains of fatigue and dizziness on standing up. Lab results show that his urine is positive for glucose and there is excessive renal loss of bicarbonate and phosphate. Abnormal function in which part of the nephron is likely?
- A.
  
  Proximal tubule
- B.
  
  Loop of Henle
- C.
  
  Distal tubule
- D.
  
  Collecting duct
17.

A novel drug is infused into healthy volunteers and is found to decrease creatinine clearance, increase the clearance of p‐aminohippurate, but not alter mean blood pressure. Calculated filtration fraction fell. By what mechanism was creatinine clearance likely reduced?
- A.
  
  Constriction of the afferent arteriole
- B.
  
  Dilation of the afferent arteriole
- C.
  
  Constriction of the efferent arteriole
- D.
  
  Dilation of the efferent arteriole
18.

In a patient suffering from pulmonary edema, there is a need to increase urine flow as rapidly as possible to remove fluids and relieve the edema. This is accomplished by the use of a diuretic ‐ a drug that inhibits the reabsorptive function in different parts of the nephron depending on the type of diuretic administered. Inhibition of the function of which nephron segment would bring about the most powerful diuretic effect?
- A.
  
  Proximal tubule
- B.
  
  Loop of Henle
- C.
  
  Distal tubule
- D.
  
  Collecting duct
19.

An increase in blood volume brings about a natriuresis and diuresis, mediated in part by alterations in proximal tubule reabsorption. What are the mechanisms that produce this response?
- A.
  
  Increased baroreceptor firing : decreased sympathetic tone: decreased peripheral resistance: decreased proximal tubule absorption
- B.
  
  Increased baroreceptor firing : Increased sympathetic tone: decreased peripheral resistance: decreased proximal tubule absorption
- C.
  
  Decreased baroreceptor firing : decreased sympathetic tone: decreased peripheral resistance: decreased proximal tubule absorption
- D.
  
  Decreased baroreceptor firing : decreased sympathetic tone: increased peripheral resistance: increased proximal tubule absorption
20.

Infants have a renal concentrating ability of about 600 mosmol/kg/H2O ‐ only about half that of an adult. In a three‐month‐old infant with this concentrating ability, and a typical 24 hour solute load of 150 mosmol, what is the minimum urine volume per 24 hours that is required to excrete this solute load?
- A.
  
  25
- B.
  
  50
- C.
  
  100
- D.
  
  125
- E.
  
  250
- F.
  
  500
21.

A consequence of inhibition of salt transport in the thick ascending limb of Henle's loop is increased potassium excretion ‐ which can result in hypokalemia. What is the main mechanism underlying this potassium wasting?
- A.
  
  Increased secretion of potassium in the thick acending limb
- B.
  
  Decreased potassium absorption in the proximal tubule
- C.
  
  Decreased aldosterone ‐ stimulated potassium secretion in the distal tubule
- D.
  
  Increased flow ‐ dependent potassium secretion in the distal tubule and collecting duct
- E.
  
  Decreased ADH ‐ stimulated potassium secretion
22.

As part of a class experiment, you ingest 1L of a salt solution which has an osmolarity of 290 mOsmol/L H2O. What changes in Starling forces occurs at the renal peritubular capillaries in response to this ingestion?
- A.
  
  Increased hydrostatic pressure and reduced oncotic pressure
- B.
  
  Increased hydrostatic pressure and increased oncotic pressure
- C.
  
  Decreased hydrostatic pressure and decreased oncotic pressure
- D.
  
  Decreased hydrostatic pressure and increased oncotic pressure
23.

A patient being evaluated after an episode of renal colic is found to have kidney stones. He is diagnosed as suffering from primary hyperparathyroidism. Compared to a normal individual what is his fractional excretion of calcium likely to be? Correct Choice
- A.
  
  Higher
- B.
  
  Lower
- C.
  
  Unchanged
24.

Preferential activation of afferent arteriolar alpha adrenoceptors will have which of the effects on renal blood flow (RBF), GFR (GFR) and filtration fraction (FF)? ..........(RBF)______________(GFR)_________________(FF)
- A.
  
  ..NO CHANGE.............DEC .............DEC
- B.
  
  ..DEC .............. DEC ............. NO CHANGE
- C.
  
  ..DEC .............. NO CHANGE ........ DEC
- D.
  
  ..INC ............. NO CHANGE .........NO CHANGE
- E.
  
  ..INC ............. INC .............. NO CHANGE
25.
- A.
  
  A
- B.
  
  B
- C.
  
  C
- D.
  
  D
- E.
  
  E