Block 6 Renal Physio Prt 1

15 Questions | Total Attempts: 222

SettingsSettingsSettings
Kidney Quizzes & Trivia

Questions and Answers
  • 1. 
    Which of the following statements about renal potassium excretion is FALSE?
    • A. 

      The secretion of K+ across the apical membrane of the collecting duct is passive.

    • B. 

      About 75% of the excreted K+ is due to K+ filtered at the glomerulus

    • C. 

      When aldosterone levels are high, the rate of K+ excretion will be high

    • D. 

      Plasma aldosterone levels will rise in response to a rise in plasma K+ concentration

  • 2. 
    A decrease in dietary sodium intake
    • A. 

      Will lead to a period of positive sodium balance where sodium accumulates in the body

    • B. 

      Will normally cause a significant rise (e.g., >10 mOsm) in plasma osmolarity

    • C. 

      Will result in the net loss of some water from the body.

    • D. 

      All of the above

  • 3. 
    Which of the following statements about tubular sodium transport is FALSE?
    • A. 

      Proximal tubular sodium reabsorption is regulated by angiotensin II.

    • B. 

      In principle cells in the distal tubule, sodium uptake involves secondary active transport

    • C. 

      Na+ and Cl− transport by the thick ascending limb makes the medullary interstitium hyperosmotic.

    • D. 

      Diuretic drugs increase the excretion of sodium by reducing apical sodium uptake

  • 4. 
    A rise in the plasma ADH concentration
    • A. 

      Will increase the water permeability of the apical membrane in the distal tubule and collecting ducts.

    • B. 

      Will be triggered by a 5% reduction in blood volume

    • C. 

      Will reduce the osmolarity of the excreted urine.

    • D. 

      Will result in reduced cAMP levels in collecting duct principle cells.

  • 5. 
    A rise in the plasma aldosterone concentration
    • A. 

      Will cause the afferent arteriole to dilate

    • B. 

      Will increase the apical-membrane potassium permeability in principle cells the collecting ducts

    • C. 

      Will directly inhibit renin release.

    • D. 

      Will occur in response to a decrease in the plasma angiotensin II concentration.

  • 6. 
    Which of the following will not influence renal renin secretion?
    • A. 

      A change in renal sympathetic nervous system activity.

    • B. 

      A rise in the plasma angiotensin II concentration.

    • C. 

      A change in the flow rate of tubular fluid past the macula densa segment.

    • D. 

      None of the above (since all can influence renin secretion).

  • 7. 
    Which of the following statements about atrial naturetic peptide (ANP) is FALSE?
    • A. 

      ANP is secreted by the cardiac atria in response to increased stretch

    • B. 

      ANP will increase GFR by dilating the afferent arteriole

    • C. 

      ANP will not affect the secretion of renin

    • D. 

      ANP reduces the Na+ permeability of the apical membrane of inner medullary collecting-duct cells.

  • 8. 
    The process of countercurrent multiplication in the renal medulla
    • A. 

      Is a passive process that occurs in the vasa recta

    • B. 

      Will not be affected by inhibition of ascending-limb sodium transport

    • C. 

      Will result in the excretion of hypotonic urine when ADH levels are low

    • D. 

      Does not involve the descending limb of Henle's loop

  • 9. 
    The plasma −  HCO3 concentration is 45 meq/L and PCO2 is 50 mmHg. Which of the following values is closest to the plasma pH?
    • A. 

      6.8

    • B. 

      7.1

    • C. 

      7.4

    • D. 

      7.6

  • 10. 
    The plasma −  HCO3 concentration is 14 meq/L, blood PCO2 is 30 mmHg and blood pH is 7.3. Based on these values, which of the following best describes the acid-base status of this person?
    • A. 

      Metabolic acidosis

    • B. 

      Metabolic alkalosis

    • C. 

      Respiratory alkalosis

    • D. 

      Respiratory acidosis

  • 11. 
    Hydrogen-ion secretion by renal tubular cells
    • A. 

      Will rise in response to a fall in the plasma bicarbonate concentration.

    • B. 

      Will result in the release of bicarbonate into plasma.

    • C. 

      Will be reduced by inhibition of cytosolic carbonic anhydrase.

    • D. 

      All of the above.

  • 12. 
    Vitamin D
    • A. 

      Is converted into calcitriol in the kidney in response to an elevated plasma phosphate concentration

    • B. 

      Activation to calcitriol in the kidney is suppressed by PTH.

    • C. 

      In its activated form stimulates gastrointestinal calcium and phosphate absorption

    • D. 

      Levels are suppressed when the plasma calcium concentration is low.

  • 13. 
    Which of the flowing statements about calcium and phosphate metabolism is FALSE?
    • A. 

      PTH increases renal calcium excretion and decreases renal phosphate excretion.

    • B. 

      Release of calcium and phosphate from bone increases when osteoclasts are stimulated by PTH.

    • C. 

      A calcium phosphate precipitate can be formed when the concentration of either ion rises substantially.

    • D. 

      A fall in plasma phosphate levels can indirectly lead to a decrease in PTH secretion.

  • 14. 
    Patients with renal insufficiency (GFR <25% of normal) often need to restrict their K+ intake because they are prone to hyperkalemia. Based upon what we have discussed in class, what would be the most probable explanation for the limited ability of these patients to excrete K+?
    • A. 

      The low GFR reduces the filtered load of potassium.

    • B. 

      Because K+ secretion is passive, the ability to secrete K+ depends on the total amount of tubular fluid that enters the distal tubules, and this is greatly reduced in these patients.

    • C. 

      Renal K+ excretion is reduced by diuretics like furosemide that are often prescribed for these patients.

    • D. 

      None of the above is a reasonable explanation

  • 15. 
    Bilateral renal-artery stenosis is a condition where both of the renal arteries are sufficiently constricted so that renal blood flow is reduced. What effect would this have on mean arterial blood pressure (BP)?
    • A. 

      BP will rise because the pressure in the afferent arteriole will be reduced, thereby stimulating renin release and angiotensin II production.

    • B. 

      BP will rise because aldosterone secretion will increase because of the high angiotensin II levels.

    • C. 

      BP will rise because extracellular fluid volume will increase.

    • D. 

      All of the above

Back to Top Back to top