front 1 A urine dipstick is normal in a healthy adult because the glomerular capillary barrier normally produces filtrate with which composition? A) Protein-rich and cell-free B) Protein-free and cell-free C) Protein-free with erythrocytes D) Protein-rich with erythrocytes | back 1 B. Protein-free and cell-free |
front 2 Glomerular filtrate is normally essentially devoid of red blood cells because glomerular capillaries are relatively impermeable to which components? A) Proteins and cellular elements B) Sodium and chloride ions C) Water and small solutes D) Glucose and amino acids | back 2 A. Proteins and cellular elements |
front 3 A patient has normal plasma calcium, but not all calcium is freely filterable at the glomerulus. Which calcium fraction is not filtered? A) Ionized calcium B) Filtered calcium C) Protein-bound calcium D) Tubular calcium | back 3 C. Protein-bound calcium |
front 4 Most plasma fatty acids are not freely filtered across glomerular capillaries because they are primarily: A) Bound to proteins B) Stored in erythrocytes C) Trapped in podocytes D) Secreted by tubules | back 4 A. Bound to proteins |
front 5 Which two variables directly determine glomerular filtration rate? A) Hematocrit and plasma sodium B) Kf and net filtration pressure C) Tubule length and urine flow D) ADH and bladder pressure | back 5 B. Kf and net filtration pressure |
front 6 The glomerular capillary filtration coefficient, Kf, is the product of which two capillary properties? A) Pressure and plasma protein B) Diameter and blood viscosity C) Permeability and surface area D) Osmolality and renal flow | back 6 C. Permeability and surface area |
front 7 In an average adult, which value best matches normal glomerular filtration rate A) 13 ml/min B) 60 ml/min C) 125 ml/min D) 1100 ml/min | back 7 C. 125 ml/min |
front 8 A normal adult has a GFR of 125 ml/min. Which daily filtration volume does this approximate? A) 3 L/day B) 30 L/day C) 60 L/day D) 180 L/day | back 8 D. 180 L/day |
front 9 Which equation correctly defines filtration fraction? A) Renal plasma flow/GFR B) GFR/renal plasma flow C) GFR/renal blood flow D) Urine flow/GFR | back 9 B. GFR/renal plasma flow |
front 10 A student compares the glomerular capillary membrane with typical systemic capillaries. What structural feature is unique? A) Three major filtration layers B) No basement membrane C) Two endothelial layers D) Complete cellular occlusion | back 10 A. Three major filtration layers |
front 11 Which sequence lists the three major layers of the glomerular capillary membrane from blood outward? A) Podocyte; endothelium; basement membrane B) Basement membrane; podocyte; endothelium C) Endothelium; basement membrane; podocyte D) Endothelium; podocyte; basement membrane | back 11 C. Endothelium; basement membrane; podocyte |
front 12 The outer epithelial cell layer of the glomerular filtration barrier is formed by which cells? A) Mesangial cells B) Podocytes C) Macula densa cells D) Juxtaglomerular cells | back 12 B. Podocytes |
front 13 The glomerular capillary endothelium contains thousands of small holes. What are these openings called? A) Slit pores B) Fenestrae C) Tight junctions D) Canaliculi | back 13 B. Fenestrae |
front 14 The glomerular basement membrane is mainly a meshwork of which substances A) Elastin and fibrinogen B) Albumin and globulin C) Collagen and proteoglycans D) Keratin and myosin | back 14 C. Collagen and proteoglycans |
front 15 Why can large amounts of water and small solutes pass through the glomerular basement membrane? A) It has large mesh spaces B) It lacks negative charge C) It actively pumps water D) It contains red cell pores | back 15 A. It has large mesh spaces |
front 16 Podocyte foot processes are separated by filtration gaps called: A) Fenestrae B) Slit pores C) Major calyces D) Tight junctions | back 16 B. Slit pores |
front 17 Through which structure does filtrate move between podocyte foot processes? A) Fenestrated liver pores B) Macula densa plaques C) Slit pores D) Cortical collecting ducts | back 17 C. Slit pores |
front 18 Which property of glomerular epithelial cells provides additional restriction to plasma protein filtration? A) Positive electrical charge B) Negative electrical charge C) High lipid solubility D) Smooth muscle contraction | back 18 B. Negative electrical charge |
front 19 Despite high filtration rate, the glomerular filtration barrier selectively filters molecules mainly according to: A) Size and electrical charge B) pH and temperature C) Sodium and potassium content D) Hormonal and neural tone | back 19 A. Size and electrical charge |
front 20 A molecule has filterability of 1.0. What does this mean? A) Not filtered at all B) Freely filtered like water C) Half as filtered as water D) Secreted after filtration | back 20 B. Freely filtered like water |
front 21 Why does the negatively charged glomerular wall repel albumin? A) Albumin is positively charged B) Albumin is negatively charged C) Albumin is lipid soluble D) Albumin is bound to calcium | back 21 B. Albumin is negatively charged |
front 22 Which glomerular wall component contributes negative charge that restricts albumin filtration? A) Proteoglycans B) Hemoglobin C) Creatinine D) Bicarbonate | back 22 A. Proteoglycans |
front 23 For dextrans of equal molecular weight, which type is filtered more readily through the glomerular barrier? A) Negatively charged dextran B) Neutral dextran C) Protein-bound dextran D) Albumin-bound dextran | back 23 B. Neutral dextran |
front 24 The negative charges of the basement membrane and podocytes most strongly restrict which molecules? A) Small positively charged ions B) Large negatively charged molecules C) Small neutral solutes D) Water molecules | back 24 B. Large negatively charged molecules |
front 25 A child develops selective albuminuria despite nearly normal kidney histology. Which early barrier abnormality best explains this? A) Loss of negative charges B) Excess slit pore closure C) Increased erythrocyte filtration D) Loss of renal blood flow | back 25 A. Loss of negative charges |
front 26 Loss of negative charges on the glomerular basement membrane before obvious histologic change is characteristic of: A) Nephrotic obstruction B) Minimal change nephropathy C) Acute pyelonephritis D) Renal papillary necrosis | back 26 B. Minimal change nephropathy |
front 27 In minimal change nephropathy, which urinary abnormality occurs because lower molecular weight proteins are filtered? A) Glycosuria B) Hematuria C) Proteinuria or albuminuria D) Ketouria | back 27 C. Proteinuria or albuminuria |
front 28 Which protein is especially likely to appear in urine when glomerular negative charge is lost? A) Albumin B) Fibrinogen C) Hemoglobin D) Myosin | back 28 A. Albumin |
front 29 Which pair correctly identifies the two immediate determinants of GFR in the filtration equation? A) Kf and net filtration pressure B) RPF and filtration fraction C) Hematocrit and renal blood flow D) Urine pressure and bladder pressure | back 29 A. Kf and net filtration pressure |
front 30 Which equation correctly describes glomerular filtration rate? A) GFR = Kf/NFP B) GFR = NFP/Kf C) GFR = Kf × NFP D) GFR = RPF × hematocrit | back 30 C. GFR = Kf × NFP |
front 31 Net filtration pressure across glomerular capillaries is the sum of which forces? A) Hydrostatic and colloid osmotic forces B) Electrical and metabolic forces C) Tubular and ureteral pressures D) Neural and hormonal forces | back 31 A. Hydrostatic and colloid osmotic forces |
front 32 Which force favors filtration across the glomerular capillary membrane? A) Bowman hydrostatic pressure B) Glomerular hydrostatic pressure C) Glomerular oncotic pressure D) Plasma protein pressure | back 32 B. Glomerular hydrostatic pressure |
front 33 Which force opposes filtration by pushing fluid back toward glomerular capillaries from Bowman’s capsule? A) Bowman hydrostatic pressure B) Bowman oncotic pressure C) Glomerular hydrostatic pressure D) Interstitial oncotic pressure | back 33 A. Bowman hydrostatic pressure |
front 34 Which force opposes filtration because plasma proteins retain water within glomerular capillaries? A) Bowman hydrostatic pressure B) Bowman oncotic pressure C) Glomerular colloid osmotic pressure D) Glomerular hydrostatic pressure | back 34 C. Glomerular colloid osmotic pressure |
front 35 Which force would promote filtration if proteins were present in Bowman’s capsule? A) Bowman colloid osmotic pressure B) Glomerular colloid osmotic pressure C) Bowman hydrostatic pressure D) Peritubular hydrostatic pressure | back 35 A. Bowman colloid osmotic pressure |
front 36 A patient with ureteral obstruction has increased pressure transmitted backward into Bowman’s capsule. What is the expected direct effect on GFR? A) GFR increases markedly B) GFR remains unchanged C) GFR decreases D) GFR doubles transiently | back 36 C. GFR decreases |
front 37 A patient with uric acid stones obstructing the ureter develops reduced filtration. Which pressure change best explains the lower GFR? A) Increased Bowman hydrostatic pressure B) Decreased plasma oncotic pressure C) Increased afferent hydrostatic pressure D) Decreased renal venous pressure | back 37 A. Increased Bowman hydrostatic pressure |
front 38 Calcium or uric acid precipitates lodge in the ureter and obstruct urinary outflow. Which downstream complication may occur if obstruction persists? A) Nephrotic syndrome B) Hydronephrosis C) Central diabetes insipidus D) Minimal change disease | back 38 B. Hydronephrosis |
front 39 Hydronephrosis from ureteral obstruction is best described as distention and dilation of which structures? A) Cortex and glomeruli B) Renal artery and vein C) Renal pelvis and calyces D) Tubules and vasa recta | back 39 C. Renal pelvis and calyces |
front 40 A patient has an obstructing ureteral stone with persistent elevated Bowman’s capsule pressure. What is the major renal risk if the obstruction is not relieved? A) Increased nephron regeneration B) Permanent kidney damage C) Increased renal oxygen delivery D) Reduced plasma protein filtration | back 40 B. Permanent kidney damage |
front 41 When fluid leaves the glomerular capillary and enters Bowman’s capsule, why does the blood left behind have a higher protein concentration? A) Proteins are not filtered B) Proteins are actively secreted C) Proteins enter podocyte cytoplasm D) Proteins bind filtered glucose | back 41 A. Proteins are not filtered |
front 42 If glomerular hydrostatic pressure is held constant, increasing blood flow into the glomerulus tends to have which effect on GFR? A) Increases GFR B) Decreases GFR C) Stops filtration D) Causes hydronephrosis | back 42 A. Increases GFR |
front 43 If glomerular hydrostatic pressure is constant but blood flow into the glomerulus falls, which effect on GFR is expected? A) GFR rises sharply B) GFR decreases C) GFR becomes pressure-independent D) GFR equals renal blood flow | back 43 B. GFR decreases |
front 44 Which set contains the three main determinants of glomerular hydrostatic pressure? A) ADH, aldosterone, renin B) Albumin, sodium, chloride C) Arterial pressure, afferent resistance, efferent resistance D) Tubule length, plasma volume, hematocrit | back 44 C. Arterial pressure, afferent resistance, efferent resistance |
front 45 A drug dilates the afferent arteriole without changing other variables. What happens to glomerular hydrostatic pressure and GFR? A) Both decrease B) Pressure decreases; GFR increases C) Pressure increases; GFR decreases D) Both increase | back 45 D. Both increase |
front 46 Afferent arteriolar dilation increases GFR primarily by producing which hemodynamic change? A) Increased glomerular hydrostatic pressure B) Increased Bowman capsule pressure C) Increased glomerular oncotic pressure D) Reduced renal artery pressure | back 46 A. Increased glomerular hydrostatic pressure |
front 47 Afferent arteriolar constriction would be expected to have which effect on glomerular hydrostatic pressure and GFR? A) Both increase B) Both decrease C) Pressure increases; GFR decreases D) Pressure decreases; GFR increases | back 47 B. Both decrease |
front 48 A patient receives a drug that moderately constricts efferent arterioles. Which immediate glomerular pressure change explains the initial GFR effect? A) Increased Bowman pressure B) Reduced glomerular pressure C) Increased glomerular hydrostatic pressure D) Reduced plasma protein pressure | back 48 C. Increased glomerular hydrostatic pressure |
front 49 At moderate levels of efferent arteriolar constriction, what is the usual effect on GFR? A) Slight increase B) Severe decrease C) No possible change D) Complete filtration arrest | back 49 A. Slight increase |
front 50 With severe efferent arteriolar constriction, what happens to GFR? A) Continues increasing indefinitely B) Decreases C) Becomes independent of proteins D) Equals renal plasma flow | back 50 B. Decreases |
front 51 Which pattern best describes GFR as efferent arteriolar constriction progresses from moderate to severe? A) Decrease then increase B) Increase then decrease C) No change then increase D) Continuous linear increase | back 51 B. Increase then decrease |
front 52 Why does severe efferent arteriolar constriction eventually decrease GFR despite raising glomerular hydrostatic pressure? A) Bowman pressure becomes negative B) Plasma proteins disappear from capillaries C) Colloid osmotic pressure rises rapidly D) Afferent arterioles fully dilate | back 52 C. Colloid osmotic pressure rises rapidly |
front 53 During severe efferent constriction, plasma protein concentration increases markedly. Which effect makes colloid osmotic pressure rise nonlinearly? A) Donnan effect B) Starling dilution C) Ureterorenal reflex D) Micturition reflex | back 53 A. Donnan effect |
front 54 In severe efferent arteriolar constriction, why does colloid osmotic pressure rise faster at higher protein concentrations? A) Proteins become freely filtered B) Protein-bound ions add osmotic force C) Bowman capsule secretes albumin D) Vasa recta stop concentrating urine | back 54 B. Protein-bound ions add osmotic force |
front 55 If renal blood flow and GFR decrease, sodium filtration decreases. What happens to sodium reabsorption and renal oxygen consumption? A) Both increase B) Reabsorption increases; oxygen falls C) Reabsorption falls; oxygen rises D) Both decrease | back 55 D. Both decrease |
front 56 Why does reduced GFR lower renal oxygen consumption? A) Less sodium is reabsorbed B) More proteins are filtered C) More glucose is secreted D) Less blood reaches cortex | back 56 A. Less sodium is reabsorbed |
front 57 Which equation correctly represents renal blood flow? A) Resistance ÷ pressure gradient B) Renal vein pressure ÷ resistance C) Pressure gradient ÷ total resistance D) GFR ÷ renal plasma flow | back 57 C. Pressure gradient ÷ total resistance |
front 58 Renal blood flow is calculated using which pressure gradient? A) Bowman minus tubular pressure B) Renal artery minus renal vein C) Glomerular minus Bowman pressure D) Afferent minus efferent pressure | back 58 B. Renal artery minus renal vein |
front 59 In the renal blood flow equation, the pressure gradient is divided by which variable? A) Total renal vascular resistance B) Filtration fraction C) Plasma colloid osmotic pressure D) Glomerular filtration coefficient | back 59 A. Total renal vascular resistance |
front 60 If renal artery and renal vein pressures remain constant, increased renal vascular resistance has what effect on renal blood flow? A) Increases flow B) Decreases flow C) Stops GFR only D) Increases filtration fraction only | back 60 B. Decreases flow |
front 61 If renal artery and renal vein pressures remain constant, decreased renal vascular resistance has what effect on renal blood flow? A) Decreases flow B) Does not affect flow C) Increases flow D) Stops medullary flow | back 61 C. Increases flow |
front 62 Which kidney region receives most renal blood flow? A) Renal cortex B) Renal medulla C) Renal pelvis D) Renal papilla | back 62 A. Renal cortex |
front 63 Blood flow to the renal medulla is supplied by which specialized capillary system A) Glomerular capillaries B) Cortical veins C) Vasa recta D) Afferent arterioles | back 63 C. Vasa recta |
front 64 The vasa recta are best described as a specialized portion of which capillary system? A) Peritubular capillary system B) Glomerular capillary system C) Portal venous system D) Pulmonary capillary system | back 64 A. Peritubular capillary system |
front 65 A patient with severe hemorrhage has intense renal sympathetic nerve activation. What is the expected effect on renal arterioles, renal blood flow, and GFR? A) Vasodilation; increased flow; increased GFR B) Vasoconstriction; decreased flow; decreased GFR C) Vasodilation; decreased flow; increased GFR D) Vasoconstriction; increased flow; decreased GFR | back 65 B. Vasoconstriction; decreased flow; decreased GFR |
front 66 Strong activation of renal sympathetic nerves directly causes which renal vascular response? A) Constriction of renal arterioles B) Dilation of renal arterioles C) Relaxation of efferent venules D) Dilation of vasa recta | back 66 A. Constriction of renal arterioles |
front 67 A patient has a moderate fall in carotid sinus and cardiopulmonary receptor pressure, causing reflex sympathetic activation. What is the usual effect on renal blood flow and GFR? A) Marked increase in both B) Complete loss of autoregulation C) Little influence on both D) Severe decrease in both | back 67 C. Little influence on both |
front 68 Which situation is most likely to substantially decrease renal blood flow and GFR through sympathetic effects? A) Mild baroreceptor unloading B) Moderate cardiopulmonary unloading C) Strong renal nerve activation D) Normal postural adjustment | back 68 C. Strong renal nerve activation |
front 69 Which adrenal medullary hormones constrict both afferent and efferent arterioles, reducing renal blood flow and GFR? A) Aldosterone and cortisol B) Norepinephrine and epinephrine C) Renin and angiotensin II D) ADH and oxytocin | back 69 B. Norepinephrine and epinephrine |
front 70 Which paired renal effect best matches norepinephrine and epinephrine release A) Arteriolar dilation; increased GFR B) Afferent dilation; reduced filtration C) Arteriolar constriction; reduced GFR D) Efferent dilation; increased flow | back 70 C. Arteriolar constriction; reduced GFR |
front 71 Endothelin is best described as which type of renal vascular mediator? A) Vasodilator from podocytes B) Vasoconstrictor from damaged endothelium C) Anticoagulant from collecting ducts D) Natriuretic peptide from macula densa | back 71 B. Vasoconstrictor from damaged endothelium |
front 72 Which mediator can be released by damaged vascular endothelial cells in the kidneys and other tissues? A) Endothelin B) Calcitriol C) Erythropoietin D) Albumin | back 72 A. Endothelin |
front 73 Which mediator is formed both in the kidneys and in the systemic circulation? A) Angiotensin II B) Evans blue dye C) Antipyrine D) 51Cr-labeled erythrocytes | back 73 A. Angiotensin II |
front 74 Nitric oxide and prostaglandins help preserve renal perfusion by counteracting vasoconstrictor effects of which mediator? A) Erythropoietin B) Calcitriol C) Angiotensin II D) Inulin | back 74 C. Angiotensin II |
front 75 Which pair of mediators opposes angiotensin II–mediated vasoconstriction in renal blood vessels? A) ADH and aldosterone B) Nitric oxide and prostaglandins C) Epinephrine and norepinephrine D) Endothelin and renin | back 75 B. Nitric oxide and prostaglandins |
front 76 Increased angiotensin II levels have which combined effect on glomerular hydrostatic pressure and renal blood flow? A) Lower pressure; lower flow B) Lower pressure; higher flow C) Raise pressure; lower flow D) Raise pressure; higher flow | back 76 C. Raise pressure; lower flow |
front 77 Angiotensin II raises glomerular hydrostatic pressure primarily by constricting which vessel? A) Afferent arteriole B) Efferent arteriole C) Interlobular artery D) Cortical vein | back 77 B. Efferent arteriole |
front 78 A patient with low effective circulating volume has increased angiotensin II levels. Angiotensin II preferentially constricts the efferent arteriole. Which effect of this response helps preserve GFR? A) Maintains glomerular capillary pressure | back 78 A. Prevents fall in glomerular pressure |
front 79 Elevated angiotensin II helps prevent decreases in GFR by maintaining which pressure? A) Bowman hydrostatic pressure B) Renal venous pressure C) Glomerular hydrostatic pressure D) Interstitial oncotic pressure | back 79 C. Glomerular hydrostatic pressure |
front 80 Angiotensin II reduces renal blood flow by efferent constriction. What downstream peritubular effect promotes sodium and water retention? A) Increased peritubular flow B) Decreased peritubular flow C) Increased Bowman pressure D) Decreased tubular permeability | back 80 B. Decreased peritubular flow |
front 81 A drug inhibits nitric oxide formation in the kidney. Which renal hemodynamic pattern is expected? A) Lower resistance; increased GFR B) Higher resistance; decreased GFR C) Lower resistance; decreased sodium excretion D) Higher resistance; increased GFR | back 81 B. Higher resistance; decreased GFR |
front 82 Inhibition of nitric oxide formation eventually causes high blood pressure through which renal effects? A) Increased GFR and natriuresis B) Decreased resistance and natriuresis C) Increased resistance and reduced natriuresis D) Decreased filtration fraction and pressure | back 82 C. Increased resistance and reduced natriuresis |
front 83 Administration of a nitric oxide synthesis inhibitor decreases urinary sodium excretion because it causes which primary renal vascular change? A) Increased renal vascular resistance B) Decreased renal vascular resistance C) Selective venous dilation D) Vasa recta rupture | back 83 A. Increased renal vascular resistance |
front 84 Renal prostaglandins help protect GFR and renal blood flow primarily by opposing vasoconstriction of which vessels? A) Afferent arterioles B) Renal veins C) Collecting ducts D) Ureters | back 84 A. Afferent arterioles |
front 85 A patient taking a prostaglandin-inhibiting drug is at risk for reduced renal perfusion during vasoconstrictor states. Which lost protective action explains this? A) Opposing afferent vasoconstriction B) Increasing efferent vasoconstriction C) Blocking macula densa signaling D) Increasing Bowman capsule pressure | back 85 A. Opposing afferent vasoconstriction |
front 86 Feedback mechanisms intrinsic to the kidneys maintain relatively constant renal blood flow and GFR despite arterial pressure changes. What is this process called A) Autoregulation B) Micturition C) Osmosis D) Protein washdown | back 86 A. Autoregulation |
front 87 Renal autoregulation refers to the kidney’s ability to keep which variables relatively constant despite arterial pressure changes? A) Sodium intake and thirst B) RBF and GFR C) Hematocrit and albumin D) ADH and aldosterone | back 87 B. RBF and GFR |
front 88 The major purpose of renal autoregulation is to maintain a relatively constant GFR and allow precise control of what? A) Water and solute excretion B) Red cell sedimentation C) Bladder wall tension D) Plasma protein synthesis | back 88 A. Water and solute excretion |
front 89 Why does arterial pressure usually affect urine volume less than expected? A) GFR cannot be filtered B) Autoregulation and tubular adaptation C) Plasma proteins freely enter filtrate D) Bowman's pressure always decreases | back 89 B. Autoregulation and tubular adaptation |
front 90 Glomerulotubular balance describes which tubular response when GFR rises? A) Tubular reabsorption increases B) Tubular reabsorption decreases C) Renin release stops completely D) Afferent resistance always rises | back 90 A. Tubular reabsorption increases |
front 91 A patient’s GFR rises, but urine volume increases less than predicted. Which tubular phenomenon helps explain this? A) Proteinuria B) Glomerulotubular balance C) Vesicoureteral reflux D) Minimal change nephropathy | back 91 B. Glomerulotubular balance |
front 92 Tubuloglomerular feedback controls GFR through which two arteriolar mechanisms? A) Afferent and efferent feedback B) Venous and lymphatic feedback C) Cortical and medullary feedback D) Sympathetic and somatic feedback | back 92 A. Afferent and efferent feedback |
front 93 Which feedback system has afferent and efferent arteriolar components that act together to regulate GFR? A) Ureterorenal reflex B) Micturition reflex C) Tubuloglomerular feedback D) Baroreceptor reflex | back 93 C. Tubuloglomerular feedback |
front 94 The juxtaglomerular complex consists of which key cell groups? A) Podocytes and mesangial cells B) Macula densa and JG cells C) Principal and intercalated cells D) Fibroblasts and epithelial cells | back 94 B. Macula densa and JG cells |
front 95 Macula densa cells are located in which nephron region? A) Initial distal tubule B) Proximal straight tubule C) Collecting duct tip D) Thin descending limb | back 95 A. Initial distal tubule |
front 96 Juxtaglomerular cells are located in the walls of which vessels? A) Renal veins only B) Afferent and efferent arterioles C) Peritubular capillaries only D) Interlobar and arcuate arteries | back 96 B. Afferent and efferent arterioles |
front 97 A fall in sodium chloride concentration at the macula densa initiates which afferent arteriolar response? A) Increased afferent resistance B) Decreased afferent resistance C) Complete afferent occlusion D) No change in resistance | back 97 B. Decreased afferent resistance |
front 98 When macula densa NaCl delivery decreases, lowering afferent arteriolar resistance helps restore GFR by increasing which pressure? A) Bowman hydrostatic pressure B) Glomerular hydrostatic pressure C) Renal venous pressure D) Interstitial oncotic pressure | back 98 B. Glomerular hydrostatic pressure |
front 99 Macula densa detection of decreased sodium chloride increases release of which substance from juxtaglomerular cells? A) Calcitriol B) Albumin C) Renin D) Endothelin | back 99 C. Renin |
front 100 A low NaCl signal at the macula densa produces which paired response? A) Afferent resistance falls; renin rises B) Afferent resistance rises; renin falls C) Efferent resistance falls; renin falls D) Bowman pressure rises; renin rises | back 100 A. Afferent resistance falls; renin rises |
front 101 Which statement best distinguishes renal autoregulation from glomerulotubular balance? A) Autoregulation stabilizes GFR; GT balance adjusts reabsorption B) Autoregulation empties bladder; GT balance controls sphincter C) Autoregulation raises proteins; GT balance lowers GFR D) Autoregulation secretes EPO; GT balance activates vitamin D | back 101 A. Autoregulation stabilizes GFR; GT balance adjusts reabsorption |
front 102 A patient has low renal arterial pressure. Macula densa signaling increases renin release, ultimately helping preserve GFR. Which sequence best explains this response? A) Renin; angiotensin I; angiotensin II B) Renin; aldosterone; prostaglandin E C) Endothelin; renin; nitric oxide D) ADH; angiotensinogen; calcitriol | back 102 A. Renin; angiotensin I; angiotensin II |
front 103 Renin released from juxtaglomerular cells functions primarily as which type of molecule? A) Steroid hormone B) Plasma protein buffer C) Enzyme D) Membrane channel | back 103 C. Enzyme |
front 104 A patient with decreased renal perfusion relies on angiotensin II to maintain filtration. Which paired effect best describes angiotensin II at the glomerulus? A) Efferent dilation; lower PG B) Afferent dilation; higher PB C) Efferent constriction; higher PG D) Afferent constriction; higher πB | back 104 C. Efferent constriction; higher PG |
front 105 A patient with bilateral renal artery stenosis is started on an ACE inhibitor and develops acute kidney injury. What mechanism best explains the fall in GFR? A) Loss of efferent constriction B) Increased afferent constriction C) Increased Bowman pressure D) Excess podocyte contraction | back 105 A. Loss of efferent constriction |
front 106 Why can ACE inhibitors cause larger-than-usual GFR reductions when renal arterial pressure is low? A) They block angiotensin II formation B) They increase plasma protein filtration C) They increase Bowman capsule pressure D) They activate renal sympathetic nerves | back 106 A. They block angiotensin II formation |
front 107 Which drug class can reduce GFR in renal artery stenosis by blocking angiotensin II action? A) Loop diuretics B) Beta blockers C) Angiotensin receptor antagonists D) Calcium channel blockers | back 107 C. Angiotensin receptor antagonists |
front 108 Renal artery stenosis creates hypertension that may depend on angiotensin II–mediated efferent tone. Which treatment complication is especially important? A) Severe decrease in GFR B) Increased glomerular bleeding C) Increased nephron regeneration D) Severe protein synthesis | back 108 A. Severe decrease in GFR |
front 109 A patient with renal artery stenosis develops acute renal failure after RAAS blockade. Which physiologic support was removed? A) Afferent vasodilation by endothelin B) Efferent constriction by angiotensin II C) Bowman pressure by prostaglandins D) Tubular secretion by aldosterone | back 109 B. Efferent constriction by angiotensin II |
front 110 A renal arteriole responds to increased arterial pressure by resisting stretch and contracting. What autoregulatory mechanism is this? A) Glomerulotubular balance B) Myogenic mechanism C) Ureterorenal reflex D) Donnan effect | back 110 B. Myogenic mechanism |
front 111 The myogenic mechanism helps maintain relatively constant renal blood flow and GFR through which vascular property? A) Resistance to stretching B) Increased protein filtration C) Reduced calcium entry D) Increased tubular secretion | back 111 A. Resistance to stretching |
front 112 Stretch of renal vascular smooth muscle allows increased entry of which ion, causing contraction? A) Sodium B) Potassium C) Calcium D) Chloride | back 112 C. Calcium |
front 113 Which sequence best describes the renal myogenic response to increased pressure? A) Stretch; calcium entry; contraction B) Stretch; sodium exit; relaxation C) Stretch; renin release; dilation D) Stretch; protein loss; filtration | back 113 A. Stretch; calcium entry; contraction |
front 114 A patient begins a high-protein diet. What is the expected effect on renal blood flow and GFR? A) Both decrease B) Both increase C) RBF decreases; GFR increases D) RBF increases; GFR decreases | back 114 B. Both increase |
front 115 A patient develops proximal tubular injury after mercury poisoning. Which tubular transport defect is expected? A) Increased NaCl reabsorption B) Decreased NaCl reabsorption C) Increased albumin filtration D) Decreased calcium filtration | back 115 B. Decreased NaCl reabsorption |
front 116 Large doses of tetracycline damage proximal tubules. Which renal handling change best matches this injury? A) Decreased sodium chloride reabsorption B) Increased protein-bound calcium filtration C) Increased efferent arteriolar resistance D) Decreased Bowman capsule pressure | back 116 A. Decreased sodium chloride reabsorption |
front 117 Which toxic exposures are specifically associated with proximal tubular damage that decreases NaCl reabsorption? A) Mercury and tetracyclines B) Lead and ethanol C) Arsenic and lithium D) Cadmium and acetaminophen | back 117 A. Mercury and tetracyclines |
front 118 The first step in urine production forms a filtrate that is protein-free and lacks red blood cells. What is this fluid called? A) Peritubular fluid B) Glomerular filtrate C) Renal lymph D) Plasma ultraconcentrate | back 118 B. Glomerular filtrate |
front 119 Which composition best describes normal glomerular filtrate? A) Protein-rich with erythrocytes B) Protein-free with salts C) Fat-rich with leukocytes D) Albumin-rich with platelets | back 119 B. Protein-free with salts |
front 120 Which plasma substances are exceptions to free filtration because large portions are protein-bound? A) Calcium and fatty acids B) Sodium and chloride C) Urea and creatinine D) Glucose and bicarbonate | back 120 A. Calcium and fatty acids |
front 121 Minimal change nephropathy causes proteinuria primarily through loss of which barrier property? A) Negative basement membrane charge B) Glomerular hydrostatic pressure C) Bowman capsule pressure D) Peritubular capillary flow | back 121 A. Negative basement membrane charge |
front 122 Minimal change nephropathy is believed to involve abnormal secretion of what factor type? A) T-cell cytokines B) B-cell antibodies C) Platelet thromboxanes D) Macrophage prostaglandins | back 122 A. T-cell cytokines |
front 123 Abnormal T-cell cytokines in minimal change nephropathy are thought to reduce which glomerular barrier feature? A) Anionic charge B) Hydrostatic pressure C) Bowman capsule volume D) Calcium permeability | back 123 A. Anionic charge |
front 124 Why does plasma protein concentration rise across glomerular capillaries? A) Fluid filters into Bowman capsule B) Albumin enters Bowman capsule C) Proteins are secreted by podocytes D) Sodium leaves through erythrocytes | back 124 A. Fluid filters into Bowman capsule |
front 125 Which two factors determine glomerular capillary colloid osmotic pressure? A) Arterial oncotic pressure; filtration fraction B) Bowman pressure; urine flow C) ADH level; sodium intake D) Hematocrit; bladder pressure | back 125 A. Arterial oncotic pressure; filtration fraction |
front 126 Moderate efferent arteriolar constriction raises glomerular hydrostatic pressure. Under what condition can this increase GFR? A) Bowman pressure rises markedly B) Renal blood flow is preserved C) Albumin becomes freely filtered D) Afferent resistance also rises | back 126 B. Renal blood flow is preserved |
front 127 Which disease-state group is associated with increased endothelin release? A) Pregnancy toxemia; renal failure; uremia B) Diabetes insipidus; tabes dorsalis; reflux C) Nephrotic syndrome; cirrhosis; ascites D) Hypernatremia; burns; diarrhea | back 127 A. Pregnancy toxemia; renal failure; uremia |
front 128 Which renal vessels are relatively protected from angiotensin II–mediated vasoconstriction? A) Preglomerular vessels B) Efferent arterioles C) Cortical veins D) Peritubular capillaries | back 128 A. Preglomerular vessels |
front 129 The afferent arteriole is protected from angiotensin II vasoconstriction partly by increased local release of which vasodilators? A) Aldosterone and ADH B) Prostaglandins and nitric oxide C) Endothelin and norepinephrine D) Renin and angiotensin I | back 129 B. Prostaglandins and nitric oxide |
front 130 A patient has elevated angiotensin II. Which paired renal effect is expected from preferential efferent constriction? A) Lower GFR; lower reabsorption B) Higher RBF; lower reabsorption C) Lower RBF; higher reabsorption D) Higher RBF; higher GFR | back 130 C. Lower RBF; higher reabsorption |
front 131 How does angiotensin II increase sodium and water reabsorption? A) It increases peritubular capillary flow B) It decreases peritubular capillary flow C) It blocks proximal sodium transport D) It raises Bowman capsule pressure | back 131 B. It decreases peritubular capillary flow |
front 132 Which set contains renal vasodilators that tend to increase GFR? A) NO, prostaglandins, bradykinin B) Endothelin, epinephrine, norepinephrine C) Angiotensin II, aldosterone, ADH D) Renin, albumin, creatinine | back 132 A. NO, prostaglandins, bradykinin |
front 133 Macula densa cells have Golgi apparatus directed toward arterioles, suggesting which function? A) Secretion toward arterioles B) Filtration of plasma proteins C) Storage of erythropoietin D) Reabsorption of fatty acids | back 133 A. Secretion toward arterioles |
front 134 ACE inhibitors and angiotensin II receptor antagonists can reduce GFR primarily by blocking which support mechanism? A) Efferent arteriolar constriction B) Afferent arteriolar dilation C) Bowman capsule relaxation D) Medullary osmotic washout | back 134 A. Efferent arteriolar constriction |
front 135 What is the expected GFR effect of ACE inhibitors or angiotensin II receptor blockers, especially when renal perfusion pressure is low? A) GFR decreases B) GFR increases C) GFR becomes unchanged D) GFR exceeds RPF | back 135 A. GFR decreases |
front 136 The myogenic mechanism of renal autoregulation depends on vascular smooth muscle doing what during increased blood pressure? A) Resisting stretch by contraction B) Releasing albumin into filtrate C) Increasing sodium secretion D) Relaxing after calcium entry | back 136 A. Resisting stretch by contraction |
front 137 What is the main protective role of the renal myogenic mechanism during increased blood pressure? A) Prevents excessive RBF and GFR rise B) Prevents all sodium filtration C) Increases bladder emptying D) Blocks angiotensin II formation | back 137 A. Prevents excessive RBF and GFR rise |
front 138 A high-protein meal increases amino acid delivery and renal tubular amino acid reabsorption. What happens to renal blood flow and GFR? A) Both decrease B) Both increase C) RBF increases; GFR decreases D) RBF decreases; GFR increases | back 138 B. Both increase |
front 139 What is the long-term renal adaptation to high protein intake? A) Kidney growth with higher RBF/GFR B) Kidney shrinkage with lower RBF/GFR C) Loss of afferent arteriolar response D) Complete macula densa suppression | back 139 A. Kidney growth with higher RBF/GFR |
front 140 Amino acids are reabsorbed primarily in which nephron segment? A) Proximal tubule B) Distal tubule C) Thin ascending limb D) Collecting duct | back 140 A. Proximal tubule |
front 141 Amino acid reabsorption in the proximal tubule increases sodium reabsorption. How does this affect macula densa NaCl delivery? A) It decreases NaCl delivery B) It increases NaCl delivery C) It has no effect D) It blocks renin release | back 141 A. It decreases NaCl delivery |
front 142 Which sequence best explains why high protein intake increases GFR? A) Amino acid reabsorption; lower macula densa NaCl; afferent dilation B) Protein filtration; higher Bowman pressure; afferent dilation C) Amino acid secretion; higher NaCl; efferent dilation D) Albumin reabsorption; lower renin; GFR increase | back 142 A. Amino acid reabsorption; lower macula densa NaCl; afferent dilation |
front 143 Increased blood glucose can increase renal blood flow and GFR through a mechanism similar to amino acids because glucose is reabsorbed where? A) Proximal tubule B) Distal tubule C) Collecting duct D) Loop thin limb | back 143 A. Proximal tubule |
front 144 How does increased glucose reabsorption in the proximal tubule affect macula densa NaCl delivery? A) Decreases NaCl delivery B) Increases NaCl delivery C) Does not affect delivery D) Completely blocks filtration | back 144 A. Decreases NaCl delivery |
front 145 A patient with hyperglycemia has increased proximal sodium-glucose reabsorption. Which tubuloglomerular response can follow? A) Afferent resistance decreases; GFR rises B) Afferent resistance increases; GFR falls C) Efferent resistance decreases; GFR falls D) Bowman pressure increases; GFR falls | back 145 A. Afferent resistance decreases; GFR rises |
front 146 Increased blood glucose is expected to have which renal hemodynamic effect? A) Decreases RBF and GFR B) Increases RBF and GFR C) Increases RBF only D) Decreases GFR only | back 146 B. Increases RBF and GFR |