front 1 A child with periodic paralysis develops weakness after receiving high-dose insulin for diabetic ketoacidosis. Which potassium shift best explains this complication? A) Intracellular potassium influx B) Extracellular potassium influx C) Reduced distal potassium secretion D) Increased intercalated-cell secretion | back 1 A. Intracellular potassium influx |
front 2 A patient is asked why serum potassium is much lower than total body potassium stores. Which compartment normally contains the highest potassium concentration? A) Plasma water B) Interstitial fluid C) Intracellular fluid D) Transcellular fluid | back 2 C. Intracellular fluid |
front 3 A patient with an aldosterone-secreting adrenal adenoma develops hypertension and muscle cramps. Which electrolyte pattern is most expected? A) Hyperkalemia with acidosis B) Hypokalemia with hypertension C) Hyperkalemia with hypotension D) Hypokalemia with hypovolemia | back 3 B. Hypokalemia with hypertension |
front 4 A patient with primary adrenal insufficiency has fatigue, weight loss, and hypotension. Which potassium abnormality is most likely? A) Hypokalemia from aldosterone excess B) Hyperkalemia from aldosterone deficiency C) Hypokalemia from beta stimulation D) Hyperkalemia from insulin excess | back 4 B. Hyperkalemia from aldosterone deficiency |
front 5 A patient receives an inhaled beta-agonist during an asthma exacerbation and later develops transient hypokalemia. Which receptor-mediated process explains this finding? A) Alpha-one renal potassium wasting B) Beta-one potassium secretion C) Beta-two intracellular potassium shift D) Muscarinic potassium reabsorption | back 5 C. Beta-two intracellular potassium shift |
front 6 A patient with acute lactic acidosis develops elevated serum potassium. Which mechanism best explains this acute change? A) Increased ROMK channel insertion B) Inhibited sodium-potassium pump C) Enhanced type A reabsorption D) Increased paracellular potassium leak | back 6 B. Inhibited sodium-potassium pump |
front 7 A patient with chronic metabolic acidosis from renal tubular disease develops low serum potassium. Which potassium pattern best matches chronic metabolic acidosis? A) Persistent hyperkalemia B) Chronic hypokalemia C) Normal serum potassium D) Pseudohyperkalemia | back 7 B. Chronic hypokalemia |
front 8 A sprinter collapses after maximal exertion and has a transient rise in serum potassium. Which scenario best matches this potassium disturbance? A) Strenuous exercise causing hyperkalemia B) Insulin surge causing hyperkalemia C) Aldosterone excess causing hyperkalemia D) Beta stimulation causing hyperkalemia | back 8 A. Strenuous exercise causing hyperkalemia |
front 9 A patient with severe dehydration has high extracellular osmolarity and elevated serum potassium. Which shift best explains this finding? A) Potassium shifts into cells B) Potassium shifts from cells C) Potassium binds plasma proteins D) Potassium enters bone matrix | back 9 B. Potassium shifts from cells |
front 10 In normal renal handling, which nephron segment reabsorbs the greatest amount of filtered potassium? A) Thick ascending limb B) Distal convoluted tubule C) Proximal convoluted tubule D) Cortical collecting duct | back 10 C. Proximal convoluted tubule |
front 11 A renal physiologist compares potassium handling across nephron segments. Besides the PCT, which segment reabsorbs significant potassium? A) Thin descending limb B) Thick ascending limb C) Connecting tubule D) Outer medullary duct | back 11 B. Thick ascending limb |
front 12 A patient with hyperkalemia is treated with measures that increase renal potassium elimination. Which cell type is most important for potassium excretion? A) Principal cells B) Type A intercalated cells C) Podocytes D) Macula densa cells | back 12 A. Principal cells |
front 13 Which nephron location is most important for regulated potassium excretion into tubular fluid? A) PCT and thin limb B) TAL and macula densa C) Distal and collecting tubules D) Glomerulus and Bowman space | back 13 C. Distal and collecting tubules |
front 14 A researcher blocks the main apical potassium secretory channels in principal cells. Which two channels are directly inhibited? A) ENaC and NCC B) BK and ROMK C) NKCC2 and NCC D) UT-A1 and UT-A3 | back 14 B. BK and ROMK |
front 15 During high tubular flow, a potassium secretory channel in principal cells becomes especially relevant. Which channel is high-conductance and flow-sensitive? A) ROMK channel B) BK channel C) ENaC channel D) NCC channel | back 15 B. BK channel |
front 16 A patient with severe total body potassium depletion begins conserving potassium in the distal nephron. Which cell type mediates this adaptive reabsorption? A) Principal cells B) Podocytes C) Type A intercalated cells D) Macula densa cells | back 16 C. Type A intercalated cells |
front 17 Severe potassium depletion activates distal potassium reabsorption through which transporter and cell type? A) ENaC in principal cells B) ROMK in principal cells C) NKCC2 in thick ascending limb D) H/K ATPase in intercalated cells | back 17 D. H/K ATPase in intercalated cells |
front 18 A patient with profound potassium depletion develops metabolic alkalosis. Which paired process best explains this acid-base disturbance? A) Potassium secretion, bicarbonate loss B) Potassium reabsorption, hydrogen secretion C) Sodium excretion, hydrogen retention D) Calcium binding, bicarbonate gain | back 18 B. Potassium reabsorption, hydrogen secretion |
front 19 Which acid-base disturbance is classically associated with acute extracellular potassium accumulation? A) Acute metabolic acidosis B) Chronic metabolic acidosis C) Metabolic alkalosis D) Respiratory alkalosis | back 19 A. Acute metabolic acidosis |
front 20 A patient with chronic diarrhea and chronic metabolic acidosis develops a potassium abnormality over time. Which pattern is expected? A) Hyperkalemia from acute shifting B) Hypokalemia from chronic acidosis C) Hyperkalemia from beta-two activity D) Hypokalemia from aldosterone deficiency | back 20 B. Hypokalemia from chronic acidosis |
front 21 A patient with hyperaldosteronism has low serum potassium. Aldosterone lowers serum potassium by which paired mechanisms? A) Excretion and cellular uptake B) Reabsorption and cellular release C) Filtration and protein binding D) Secretion and phosphate complexing | back 21 A. Excretion and cellular uptake |
front 22 A patient receives high-dose loop diuretics and develops hypokalemia. Increased distal tubular flow promotes which potassium process? A) Reabsorption B) Complexing C) Excretion D) Filtration | back 22 C. Excretion |
front 23 Which set of conditions promotes potassium excretion by increasing distal tubular flow? A) Hypovolemia, hyponatremia, Addison disease B) Hypernatremia, diuretics, volume expansion C) Acidosis, insulin, beta stimulation D) Dehydration, exercise, adrenal failure | back 23 B. Hypernatremia, diuretics, volume expansion |
front 24 A patient with metabolic alkalosis develops paresthesias and carpopedal spasm despite normal total calcium. Which mechanism explains this tetany? A) Less protein-bound calcium B) More ionized calcium C) More protein-bound calcium D) Less phosphate-complexed calcium | back 24 C. More protein-bound calcium |
front 25 Which acid-base state makes hypocalcemic tetany more likely by lowering freely ionized calcium? A) Metabolic alkalosis B) Metabolic acidosis C) Respiratory acidosis D) Normal acid-base status | back 25 A. Metabolic alkalosis |
front 26 Which hormone is a major regulator of renal calcium handling and calcium homeostasis? A) Aldosterone B) Insulin C) PTH D) Epinephrine | back 26 C. PTH |
front 27 Only a fraction of plasma calcium is freely filterable at the glomerulus. What percentage of plasma calcium is filtered? A) 40% B) 60% C) 80% D) 100% | back 27 B. 60% |
front 28 Why is only about 60% of plasma calcium filtered by the kidney? A) It is all intracellular B) It is all secreted C) It is freely ionized D) It is entirely reabsorbed | back 28 C. It is freely ionized |
front 29 A nephron segment reabsorbs the largest fraction of filtered calcium, roughly 65%. Which segment is this? A) Proximal convoluted tubule B) Thick ascending limb C) Distal convoluted tubule D) Collecting duct | back 29 A. Proximal convoluted tubule |
front 30 Which nephron segment reabsorbs approximately 25–30% of filtered calcium? A) Proximal convoluted tubule B) Loop of Henle C) Distal convoluted tubule D) Collecting tubule | back 30 B. Loop of Henle |
front 31 Which nephron segment reabsorbs only about 4–9% of filtered calcium? A) Proximal convoluted tubule B) Thin descending limb C) Distal convoluted tubule D) Cortical collecting duct | back 31 C. Distal convoluted tubule |
front 32 Most calcium reabsorption in the proximal tubule occurs through which pathway? A) Transcellular active pathway B) Paracellular passive pathway C) Vesicular endocytic pathway D) Hormonal secretory pathway | back 32 B. Paracellular passive pathway |
front 33 A drug selectively blocks passive paracellular calcium movement. Which nephron segment’s major calcium reabsorption pathway is most affected? A) PCT B) TAL C) DCT D) Collecting duct | back 33 A. PCT |
front 34 Calcium reabsorption in the distal convoluted tubule differs from proximal calcium reabsorption because it is primarily what type of process? A) Passive paracellular transport B) Active transcellular transport C) Flow-dependent secretion D) Protein-bound filtration | back 34 B. Active transcellular transport |
front 35 A patient’s distal convoluted tubule calcium reabsorption is impaired by ATP depletion. Why does this occur? A) DCT calcium transport requires ATP B) PCT calcium transport requires ATP C) Filtered calcium requires ATP D) Protein binding requires ATP | back 35 A. DCT calcium transport requires ATP |
front 36 A trauma patient is hypotensive from blood loss and has reduced calcium excretion. Which serum calcium change is expected? A) Hypocalcemia B) Normocalcemia C) Hypercalcemia D) Pseudohypocalcemia | back 36 C. Hypercalcemia |
front 37 Why can hypotension cause hypercalcemia through renal handling changes? A) Reduced PCT sodium reabsorption B) Increased PCT calcium secretion C) Increased PCT water retention D) Increased distal calcium excretion | back 37 C. Increased PCT water retention |
front 38 A patient with vomiting develops metabolic alkalosis and altered renal calcium handling. Which effect on urinary calcium loss is expected? A) Increased calcium excretion B) Reduced calcium excretion C) Unchanged calcium filtration D) Increased calcium secretion | back 38 B. Reduced calcium excretion |
front 39 Which acid-base comparison best matches renal calcium excretion? A) Acidosis reduces, alkalosis promotes B) Alkalosis promotes, acidosis reduces C) Alkalosis reduces, acidosis promotes D) Both reduce calcium excretion | back 39 C. Alkalosis reduces, acidosis promotes |
front 40 A patient with metabolic acidosis develops increased urinary calcium loss. Which renal calcium effect best matches this acid-base state? A) Promoted calcium excretion B) Reduced calcium excretion C) Increased calcium protein binding D) Reduced filtered calcium load | back 40 A. Promoted calcium excretion |
front 41 A renal transporter defect primarily reduces phosphate reclamation from tubular fluid. Which site normally reabsorbs most filtered phosphate? A) Thick ascending limb B) Distal convoluted tubule C) Collecting tubule D) Proximal convoluted tubule | back 41 D. Proximal convoluted tubule |
front 42 Most phosphate reabsorption in the proximal tubule occurs through which transport mechanism? A) Sodium-phosphate cotransport B) Hydrogen-phosphate antiport C) Potassium-phosphate cotransport D) Chloride-phosphate exchange | back 42 A. Sodium-phosphate cotransport |
front 43 A patient with primary hyperparathyroidism has increased PTH. What happens to renal phosphate reabsorption? A) It increases markedly B) It decreases C) It remains unchanged D) It shifts distally | back 43 B. It decreases |
front 44 A patient with elevated PTH develops hypophosphatemia. Which nephron process is directly suppressed? A) TAL magnesium transport B) DCT calcium secretion C) PCT phosphate reabsorption D) Collecting duct sodium excretion | back 44 C. PCT phosphate reabsorption |
front 45 A patient has impaired divalent cation reabsorption in the thick ascending limb. Which electrolyte is most affected at its major reabsorptive site? A) Calcium B) Phosphate C) Sodium D) Magnesium | back 45 D. Magnesium |
front 46 Which pairing of solute and major renal reabsorptive site is most accurate? A) Phosphate—distal convoluted tubule B) Magnesium—thick ascending limb C) Calcium—collecting duct D) Sodium—thin descending limb | back 46 B. Magnesium—thick ascending limb |
front 47 Which set correctly matches major reabsorption sites? A) Phosphate PCT, magnesium TAL B) Phosphate TAL, magnesium PCT C) Phosphate DCT, magnesium PCT D) Phosphate CD, magnesium DCT | back 47 A. Phosphate PCT, magnesium TAL |
front 48 A patient has an acute increase in GFR. What happens to sodium reabsorption because more sodium reaches the tubules? A) It decreases B) It stops C) It increases D) It becomes aldosterone-independent | back 48 C. It increases |
front 49 An experiment raises GFR while tubular reabsorptive mechanisms remain intact. Which paired change is expected? A) Less sodium delivery, less reabsorption B) More sodium delivery, more reabsorption C) Less sodium delivery, more reabsorption D) More sodium delivery, less reabsorption | back 49 B. More sodium delivery, more reabsorption |
front 50 A patient’s arterial blood pressure rises substantially. Which renal output change is most expected? A) Increased urine output B) Reduced urine output C) Absent urine production D) Unchanged urine output | back 50 A. Increased urine output |
front 51 A patient receives angiotensin II infusion. Which effect on tubular sodium handling is expected? A) Decreased sodium reabsorption B) Increased sodium excretion C) Increased sodium reabsorption D) Abolished sodium filtration | back 51 C. Increased sodium reabsorption |
front 52 A patient with renal artery stenosis has high angiotensin II. Which renal sodium effect helps expand extracellular volume? A) Reduced sodium filtration B) Increased sodium reabsorption C) Increased sodium wasting D) Blocked sodium transport | back 52 B. Increased sodium reabsorption |
front 53 A patient with Conn syndrome has high aldosterone but avoids progressive sodium overload. Which mechanism maintains sodium balance? A) Pressure natriuresis escape B) ADH escape C) Tubuloglomerular feedback D) Aldosterone receptor loss | back 53 A. Pressure natriuresis escape |
front 54 In Conn syndrome, hypertension eventually limits aldosterone-driven sodium retention. Which sequence best explains this escape? A) Low BP causes sodium retention B) High BP causes pressure natriuresis C) Low aldosterone causes natriuresis D) High ADH causes potassium wasting | back 54 B. High BP causes pressure natriuresis |
front 55 A patient with an aldosterone-producing adenoma develops hypertension without unlimited sodium retention. Which process overrides aldosterone’s sodium-retaining effect? A) Osmotic diuresis B) Urea recycling C) Pressure natriuresis D) Potassium conservation | back 55 C. Pressure natriuresis |
front 56 A patient secretes large amounts of ADH and retains water. Which serum sodium-volume pattern is most expected? A) Hypervolemic hypernatremia B) Hypovolemic hyponatremia C) Euvolemic hypernatremia D) Euvolemic hyponatremia | back 56 D. Euvolemic hyponatremia |
front 57 Why can excessive ADH cause hyponatremia without marked hypervolemia? A) Potassium retention dilutes sodium B) Pressure diuresis favors sodium excretion C) Aldosterone suppresses water retention D) GFR eliminates all water | back 57 B. Pressure diuresis favors sodium excretion |
front 58 A patient with SIADH retains water but maintains near-normal volume. Which paired renal response best explains this? A) Water loss, sodium retention B) Sodium loss, pressure diuresis C) Calcium loss, osmotic diuresis D) Potassium loss, aldosterone escape | back 58 B. Sodium loss, pressure diuresis |
front 59 Large amounts of ADH lower serum osmolarity primarily through which immediate effect? A) Increased sodium filtration B) Reduced tubular water entry C) Increased water retention D) Increased phosphate reabsorption | back 59 C. Increased water retention |
front 60 After a small myocardial infarction, compensatory renal responses help maintain cardiac output. What happens to blood volume? A) It decreases B) It increases C) It remains fixed D) It becomes isotonic only | back 60 B. It increases |
front 61 A minor myocardial infarction lowers effective cardiac performance. Which compensatory volume change helps preserve cardiac output? A) Expanded blood volume B) Reduced blood volume C) Reduced plasma proteins D) Increased free water loss | back 61 A. Expanded blood volume |
front 62 A patient with nephrotic syndrome loses large amounts of protein in urine. What happens to aldosterone levels? A) Mildly decreased B) Unchanged C) Markedly increased D) Completely suppressed | back 62 C. Markedly increased |
front 63 Why does nephrotic syndrome strongly increase aldosterone secretion? A) To increase calcium filtration B) To preserve blood volume C) To suppress proteinuria D) To reduce sodium reabsorption | back 63 B. To preserve blood volume |
front 64 Which pairing best matches the volume-regulatory response? A) Conn syndrome—pressure natriuresis escape B) SIADH—aldosterone escape C) Nephrotic syndrome—low aldosterone D) Minor MI—blood volume loss | back 64 A. Conn syndrome—pressure natriuresis escape |