McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Biology .
Chapters
| 501. |
With regard to chemoreceptors, all of the following are true EXCEPT: |
| A. | the medullary chemoreceptors respond to a change in blood pCO2 |
| B. | the medullary chemoreceptors respond to blood (H+) |
| C. | the predominant peripheral chemoreceptors are located in the carotid and aortic bodies |
| D. | the peripheral chemoreceptors respond to pO2 |
| E. | the peripheral chemoreceptors respond to blood (H+) |
| Answer» B. the medullary chemoreceptors respond to blood (H+) | |
| 502. |
In the autonomic nerve system, β antagonism results in: |
| A. | constriction of the renal vasculature |
| B. | decreased velocity of conduction in the atrioventricular node |
| C. | decreased velocity of conduction in the HIS/Purkinje system |
| D. | decreased ventricular contractility |
| E. | increased insulin and glucagon secretion |
| Answer» E. increased insulin and glucagon secretion | |
| 503. |
The reticular activating system: |
| A. | has depressed conduction during anaesthesia |
| B. | is located in the pons |
| C. | is a simple collection of parallel nerve fibres |
| D. | has no input from the cranial nerves |
| E. | is electrically isolated from the cerebral cortex |
| Answer» A. has depressed conduction during anaesthesia | |
| 504. |
Which substance is 60 times more concentrated in urine than in plasma? |
| A. | glucose |
| B. | creatinine |
| C. | sodium |
| D. | urea |
| Answer» D. urea | |
| 505. |
Regarding the anatomy of the kidney: |
| A. | the afferent arteriole is smaller than the efferent |
| B. | the kidney contains 1.3 million nephrons |
| C. | there are three layers separating the blood in the arteriole from the glomerular filtrate |
| D. | podocytes are contractile and regulate GFR |
| Answer» B. the kidney contains 1.3 million nephrons | |
| 506. |
Regarding the glomerulus filtration fx: |
| A. | it allows passage of molecules up to 4nm diameter freely, and up to 8nm with some difficulty depending on charge |
| B. | positively charged molecules pass more easily than neutral |
| C. | endothelial pores have a greater diameter than podocyte filtration slits |
| D. | the basal lamina contains interruptions |
| Answer» A. it allows passage of molecules up to 4nm diameter freely, and up to 8nm with some difficulty depending on charge | |
| 507. |
The renal tubule: |
| A. | all sections are lined with cuboidal epithelial cells with luminal microvilli |
| B. | the thick loop of Henle rises to lie adjacent to its glomerulus |
| C. | there are a greater number of juxtamedullary nephrons than cortical |
| D. | the lacis cells of the juxtaglomerular apparatus secrete renin |
| Answer» B. the thick loop of Henle rises to lie adjacent to its glomerulus | |
| 508. |
Regarding glomerular blood supply: |
| A. | the efferent arterioles are branches of the interlobular arterioles |
| B. | the descending vasa recta vessels contain fenestrated endothelium to assist urea transport |
| C. | the efferent arterioles empties into the peritubular network |
| D. | the glomerular capillaries drain into the efferent vein |
| Answer» C. the efferent arterioles empties into the peritubular network | |
| 509. |
If [urine]PAH = 14mg/ml, urine flow = 0.9ml/min and [plasma]PAH = 0.02mg/ml
|
| A. | ClPAH = 630, renal blood flow = 1273ml/min |
| B. | ClPAH = 630, renal blood flow = 700mb/min |
| C. | ClPAH = 77, renal blood flow = 155mb/min |
| D. | ClPAH = 777mb/min, renal blood flow = 1569mb/min |
| Answer» A. ClPAH = 630, renal blood flow = 1273ml/min | |
| 510. |
Renal blood pressure: |
| A. | the pressure drop across the glomerulus is about 20mmHg |
| B. | pressure in the renal vein is about 15mmHg |
| C. | the glomerular capillary pressure is about 80% that of arterial |
| D. | the greatest drop in pressure (percentage wise) is from the efferent arteriole to the peritubular capillary |
| Answer» D. the greatest drop in pressure (percentage wise) is from the efferent arteriole to the peritubular capillary | |
| 511. |
Regarding renal innervation: |
| A. | transplanted kidneys initially have reduced concentrating ability because of lack of innervation of the juxtaglomerular cells and therefore decreased renin secretion |
| B. | norepinephrine acts directly on α receptors on the juxtaglomerular cells |
| C. | renal blood flow increases during exercise |
| D. | autoregulation of renal blood flow can be disrupted by angiotensin-II inhibitors when renal perfusion is low |
| Answer» D. autoregulation of renal blood flow can be disrupted by angiotensin-II inhibitors when renal perfusion is low | |
| 512. |
The glomerular filtration rate: |
| A. | is usually in the order of 125mL/min for an average healthy male |
| B. | is equal to the clearance of creatinine |
| C. | is indirectly related to filtration coefficient |
| D. | is determined by [urine]inulin |
| Answer» A. is usually in the order of 125mL/min for an average healthy male | |
| 513. |
Which of the following will cause an increase in GFR? |
| A. | dehydration |
| B. | ureteral obstruction |
| C. | afferent arteriole constriction |
| D. | hypoproteinaemia |
| Answer» D. hypoproteinaemia | |
| 514. |
Na+ resorption does not occur in which part of the nephron? |
| A. | proximal convoluted tubule |
| B. | thin descending loop of Henle |
| C. | thick ascending loop of Henle |
| D. | distal convoluted tubule |
| E. | collecting duct |
| Answer» B. thin descending loop of Henle | |
| 515. |
Which is NOT resorbed via cotransport with Na+ in the PCT? |
| A. | lactate |
| B. | phosphate |
| C. | hydrogen |
| D. | amino acids |
| E. | collecting duct |
| Answer» C. hydrogen | |
| 516. |
Fanconi’s syndrome of decreased levels of ATP in the tubular epithelium of the PCT: |
| A. | decreases Na+ extrusion from the cell into the interstitium |
| B. | causes increased phosphate absorption |
| C. | causes metabolic alkalosis |
| D. | results in decreased amino acid excretion |
| E. | collecting duct |
| Answer» A. decreases Na+ extrusion from the cell into the interstitium | |
| 517. |
Anti-diuretic hormone controls the concentration of urine, |
| A. | and can concentrate urine to up to 2500mosm/kg H??? H2O |
| B. | in its absence, the collecting duct is impermeable to water |
| C. | causing the ultimate resorption of up to 99.7% of the filtrate |
| D. | by causing upregulation of aquaporin-1 channels |
| E. | collecting duct |
| Answer» C. causing the ultimate resorption of up to 99.7% of the filtrate | |
| 518. |
Regarding H+ renal excretion: |
| A. | the distal convoluted tubule brush border contains carbonic anhydrase |
| B. | H+ secretion occurs in all segments of the nephrons |
| C. | H+ + NH3 →NH4+ is the most significant tubular buffering reaction |
| D. | CO2 is recycled / resorbed in the PCT to allow enhanced acid secretion |
| E. | collecting duct |
| Answer» D. CO2 is recycled / resorbed in the PCT to allow enhanced acid secretion | |
| 519. |
In the nervous control of the bladder which nerves do NOT play a role in micturition? |
| A. | sympathetic nerves from L2 in hypogastric nerve |
| B. | somatic motor neurons in pudendal nerve |
| C. | sensory neurons to S2/3 in pelvic nerves |
| D. | parasympathetic supply in pelvic nerves |
| E. | collecting duct |
| Answer» A. sympathetic nerves from L2 in hypogastric nerve | |
| 520. |
Which is the least significant buffering system in the blood? |
| A. | H+ + plasma protein HProt |
| B. | H+ +HPO4 2- H2PO4- |
| C. | H+ + HCO3 - H2CO3 |
| D. | H+ + Hb HHb |
| E. | collecting duct |
| Answer» B. H+ +HPO4 2- H2PO4- | |
| 521. |
In which body compartment is the bicarb buffering system least important? |
| A. | intracellular |
| B. | interstitial |
| C. | CSF |
| D. | blood |
| E. | collecting duct |
| Answer» A. intracellular | |
| 522. |
In which state is extracellular buffering more important than intracellular? |
| A. | respiratory acidosis |
| B. | respiratory alkalosis |
| C. | metabolic acidosis |
| D. | metabolic alkalosis |
| E. | collecting duct |
| Answer» D. metabolic alkalosis | |
| 523. |
Renal acid secretion is enhanced by: |
| A. | respiratory acidosis |
| B. | respiratory alkalosis |
| C. | hyperkalaemia |
| D. | carbonic anhydrase inhibition |
| E. | collecting duct |
| Answer» A. respiratory acidosis | |
| 524. |
Carbonic anhydrase is not inhibited by: |
| A. | cyanide |
| B. | zinc |
| C. | azide |
| D. | sulphide |
| E. | collecting duct |
| Answer» B. zinc | |
| 525. |
What increases GFR: |
| A. | moderate constriction of efferent arterioles |
| B. | moderate constriction of afferent arterioles |
| C. | increased Bowman’s capsule pressure |
| D. | increased glomerular capillary osmotic pressure |
| E. | collecting duct |
| Answer» A. moderate constriction of efferent arterioles | |
| 526. |
What increases the anion gap: |
| A. | increased concentration of Mg2+ |
| B. | decreased concentration of plasma proteins |
| C. | decreased concentration of lactate |
| D. | increased concentration of ketoacids |
| E. | collecting duct |
| Answer» D. increased concentration of ketoacids | |
| 527. |
Which is CORRECT? |
| A. | humans have approximately 1.3 million nephrons |
| B. | glomerular membrane excludes substances greater than 4nm in diameter |
| C. | total area of glomerular capillary endothelium is 8m2 |
| D. | nephrons length is 45-65mm |
| E. | collecting duct |
| Answer» D. nephrons length is 45-65mm | |
| 528. |
Which of the following is TRUE? |
| A. | U/P ratio for creatinine is 150mg/dl |
| B. | U/P ratio for glucose is 10 |
| C. | Na concentration in the urine usually exceeds over 150mg/dl |
| D. | the usual glucose excretion in the urine is 100mg/dl |
| E. | collecting duct |
| Answer» A. U/P ratio for creatinine is 150mg/dl | |
| 529. |
Which of the following is FALSE? |
| A. | proximal convoluted tubular cells have lateral intercellular spaces |
| B. | the cells in the descending loop of Henle have large numbers of mitochondria |
| C. | the ascending loop of Henle contributes to the formation of juxtaglomerular apparatus |
| D. | in humans only 15% of the nephrons have long loops |
| E. | collecting duct |
| Answer» B. the cells in the descending loop of Henle have large numbers of mitochondria | |
| 530. |
Regarding tubular function: |
| A. | 90% of the water is absorbed by the proximal convoluted tubule |
| B. | renal threshold for glucose is 300mg/dl |
| C. | the main mechanism of the Na reabsorption from the tubular fluid to proximal convoluted tubule is via Na/K/ATP a pump |
| D. | the main mechanism of Na absorption in the ascending loop of Henle is via cotransport of Na/K/2Cl: |
| E. | collecting duct |
| Answer» D. the main mechanism of Na absorption in the ascending loop of Henle is via cotransport of Na/K/2Cl: | |
| 531. |
The maximum effect of vasopressin occurs at: |
| A. | distal convoluted tubule |
| B. | proximal convoluted tubule |
| C. | cortical part of the collecting duct |
| D. | medullary part of collecting duct |
| E. | thick ascending limb of loop of Henle |
| Answer» C. cortical part of the collecting duct | |
| 532. |
Regarding the buffer system in the tubular fluid, which one is TRUE? |
| A. | the main buffer system is H2PO4 |
| B. | the main mechanism of H+ secretion in the proximal tubule is via proton pump |
| C. | dibasic phosphate buffer is most effective at proximal convoluted tubule |
| D. | the H+ secretion at proximal tubule is mediated Na/K/ATPase |
| E. | thick ascending limb of loop of Henle |
| Answer» D. the H+ secretion at proximal tubule is mediated Na/K/ATPase | |
| 533. |
Regarding the renin-angiotensin system, which is CORRECT? |
| A. | renin has many functions including the formation of angiotensin I from angiotensinogen |
| B. | after nephrectomy, circulating levels of prorenin fall |
| C. | renin is formed in the juxtaglomerular cells of the kidney |
| D. | active renin has a half-life in the circulation of 40 minutes or less |
| E. | prorenin is biologically active |
| Answer» C. renin is formed in the juxtaglomerular cells of the kidney | |
| 534. |
All of the following increase renin secretion EXCEPT: |
| A. | sodium depletion |
| B. | diuretics |
| C. | hypertension |
| D. | cardiac failure |
| E. | cirrhosis |
| Answer» C. hypertension | |
| 535. |
All of the following factors inhibit renin secretion EXCEPT: |
| A. | prostaglandins |
| B. | angiotensin II |
| C. | vasopressin |
| D. | increased afferent arteriolar pressure |
| E. | increased Na+ and Cl- reabsorption across the macular densa |
| Answer» A. prostaglandins | |
| 536. |
Which of the following blood gas results is consistent with a three-week residence at 4000m altitude, after previously living at sea-level? pH HCO3 - (meq/L) pCO2 |
| A. | 7.40 24.1 40 |
| B. | 7.50 30.1 40 |
| C. | 6.96 5.0 23 |
| D. | 7.34 33.5 64 |
| E. | 7.48 18.7 26 |
| Answer» E. 7.48 18.7 26 | |
| 537. |
In a resting adult, the kidneys receive how much of the cardiac output? |
| A. | 15% |
| B. | 20% |
| C. | 25% |
| D. | 30% |
| E. | 35% |
| Answer» C. 25% | |
| 538. |
Which of the following is INCORRECT regarding regulation of renal blood flow? |
| A. | noradrenaline constricts the renal vessels |
| B. | dopamine causes renal vasodilation and natriuresis |
| C. | angiotensin II exerts a constrictor effect on the efferent arterioles |
| D. | prostaglandins increase blood flow in the renal cortex and decrease blood flow in the renal medulla |
| E. | acetylcholine produces renal vasoconstriction |
| Answer» E. acetylcholine produces renal vasoconstriction | |
| 539. |
Erythropoietin: |
| A. | is produced in the juxtaglomerular cells of the kidney |
| B. | production is stimulated by theophylline |
| C. | secretion is facilitated by the acidosis that develops at high altitude |
| D. | has a half-life in the circulation of about 5 hours |
| E. | is produced predominantly in the spleen in neonates |
| Answer» D. has a half-life in the circulation of about 5 hours | |
| 540. |
Mesengial cell contraction is stimulated by: |
| A. | ANP |
| B. | dopamine |
| C. | PGE2 |
| D. | cAMP |
| E. | angiotensin II |
| Answer» E. angiotensin II | |
| 541. |
Ethanol’s action as a diuretic occurs by: |
| A. | inhibition of vasopressin secretion |
| B. | inhibition of the action of vasopressin on the collecting duct |
| C. | production of an osmotic diuresis |
| D. | decreasing tubular reabsorption of Na and increasing GFR |
| E. | inhibition of the Na+ -K+ -Cl- cotransporter in the medullary thick ascending limb of the loop of Henle |
| Answer» B. inhibition of the action of vasopressin on the collecting duct | |
| 542. |
With regard to diuretics: |
| A. | frusemide acts on the thick ascending limb of the loop of Henle |
| B. | antagonists to V2 vasopressin receptors act on the early portion of the distal convoluted tubule |
| C. | thiazides act primarily on the thick ascending limb of the loop of Henle |
| D. | loop diuretics act on the collecting ducts |
| E. | aldosterone antagonists act on the early portion of the distal convoluted tubule |
| Answer» A. frusemide acts on the thick ascending limb of the loop of Henle | |
| 543. |
In the presence of vasopressin, most filtered water is absorbed in the? |
| A. | proximal tubule |
| B. | loop of Henle |
| C. | distal tubule |
| D. | cortical collecting system |
| E. | medullary collecting system |
| Answer» A. proximal tubule | |
| 544. |
Which pattern of laboratory findings in the tale below is most consistent with a diagnosis of diabetes insipidis? 24 Hr Urine Vol Ketones Glucose Protein |
| A. | 4.0 + 0 0 |
| B. | 6.2 2+ 4+ 0 |
| C. | 1.6 0 0 4+ |
| D. | 6.4 0 0 0 |
| E. | 5.0 0 0 3+ |
| Answer» D. 6.4 0 0 0 | |
| 545. |
On which of the following does aldosterone exert its greatest effect? |
| A. | glomerulus |
| B. | proximal tubule |
| C. | thin portion of loop of Henle |
| D. | thick portion of look of Henle |
| E. | cortical collecting system |
| Answer» E. cortical collecting system | |
| 546. |
What is the clearance of a substance when its concentration in plasma is 1mg/ml, its concentration in urine is 10mg/ml and the urine flow is 2ml/min? |
| A. | 2ml/min |
| B. | 10ml/min |
| C. | 20ml/min |
| D. | 200ml/min |
| E. | clearance cannot be determined from the information given |
| Answer» C. 20ml/min | |
| 547. |
Glucose reabsorption occurs in the: |
| A. | proximal tubule |
| B. | loop of Henle |
| C. | distal tubule |
| D. | cortical collecting system |
| E. | medullary collecting system |
| Answer» A. proximal tubule | |
| 548. |
As urine flow increases during osmotic diuresis: |
| A. | the osmolality of urine falls |
| B. | the osmolality of urine increases |
| C. | the osmolality of urine approaches that of plasma |
| D. | the osmolality of urine is unchanged |
| E. | the osmolality of urine depends primarily on other factors |
| Answer» C. the osmolality of urine approaches that of plasma | |
| 549. |
Which of the following is NOT true regarding the voiding reflex? |
| A. | it involves parasympathetic fibres |
| B. | it remains intact in the period of spinal shock following transaction of the spinalcord |
| C. | it occurs when the bladder volume reaches 300-400mls |
| D. | it is integrated in the sacral segments of the spinal cord |
| E. | its threshold is altered by inhibitory fibres from the brainstem |
| Answer» B. it remains intact in the period of spinal shock following transaction of the spinalcord | |
| 550. |
Which of the following substances is NOT actively secreted in to the tubular lumen by the proximal renal tubule? |
| A. | urate |
| B. | para-amino hippuric acid |
| C. | catecholamines |
| D. | sodium |
| E. | creatinine |
| Answer» D. sodium | |
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