HESI A2 Entrance Exam Chamberlain Practice Test with a
Review of Questions and Correct Detailed Answers - 139
Questions
Section 1: Anatomy and Physiology (Questions 1-19)
1 A researcher is studying the effect of a novel drug that blocks the activity of phosphofructokinase-1 (PFK-1) in
hepatocytes. Which of the following metabolic consequences is most likely to occur in these cells under aerobic
conditions?
A) Increased glycogen synthesis due to elevated glucose-6-phosphate levels.
B) Accumulation of fructose-1,6-bisphosphate and increased flux through the pentose phosphate pathway.
C) Decreased lactate production and increased gluconeogenesis from lactate.
D) Reduced ATP production and compensatory upregulation of fatty acid oxidation.
Answer: A
Rationale: PFK-1 is a key regulatory enzyme in glycolysis. Blocking it causes accumulation of upstream metabolites
like glucose-6-phosphate, which allosterically activates glycogen synthase, promoting glycogen synthesis. Option
B is incorrect because fructose-1,6-bisphosphate is downstream of PFK-1 and would decrease, not accumulate.
Option C: decreased glycolysis reduces pyruvate and thus lactate, but gluconeogenesis from lactate is not directly
stimulated. Option D: ATP production from glycolysis decreases, but fatty acid oxidation is not directly
upregulated by PFK-1 inhibition; cells may rely more on oxidative phosphorylation but not necessarily via
increased fatty acid oxidation.
2 In a patient with a complete transection of the spinal cord at the T10 level, which of the following clinical
findings is expected immediately after the injury?
A) Hyperreflexia and spasticity in the lower extremities.
B) Flaccid paralysis and loss of deep tendon reflexes below the lesion.
C) Preservation of voluntary motor function in the lower extremities but loss of sensation.
D) Babinski sign present bilaterally with intact cremasteric reflex.
Answer: B
Rationale: Immediately after spinal cord transection, spinal shock occurs, characterized by flaccid paralysis,
areflexia, and loss of sensation below the level of the lesion. Hyperreflexia and spasticity (option A) develop later,
after spinal shock resolves. Option C is incorrect because both motor and sensory functions are lost. Option D:
Babinski sign is an upper motor neuron sign that appears later, and the cremasteric reflex is lost during spinal
shock.
3 A 45-year-old individual with chronic hypertension is found to have a left ventricular hypertrophy. Which of the
following best explains the underlying physiological adaptation?
A) Increased afterload leads to eccentric hypertrophy with increased ventricular volume.
B) Increased preload leads to concentric hypertrophy with increased wall thickness.
C) Increased afterload leads to concentric hypertrophy with increased wall thickness.
D) Increased preload leads to eccentric hypertrophy with decreased wall thickness.
Answer: C
Rationale: Chronic hypertension increases afterload (the pressure the heart must overcome to eject blood). The left
ventricle adapts by concentric hypertrophy, where the wall thickens without significant chamber enlargement.
Option A is incorrect because increased afterload causes concentric, not eccentric hypertrophy. Option B: increased
,preload typically causes eccentric hypertrophy (e.g., in volume overload). Option D: eccentric hypertrophy
involves increased ventricular volume and wall thickness, not decreased.
4 Which of the following correctly describes the movement of ions during the repolarization phase of a cardiac
ventricular action potential?
A) Rapid influx of sodium ions through voltage-gated sodium channels.
B) Influx of calcium ions through L-type calcium channels.
C) Efflux of potassium ions through delayed rectifier potassium channels.
D) Influx of chloride ions through calcium-activated chloride channels.
Answer: C
Rationale: Repolarization in ventricular myocytes is primarily due to efflux of potassium ions through delayed
rectifier potassium channels (IKr and IKs). Option A describes the rapid depolarization phase (phase 0). Option B
describes the plateau phase (phase 2). Option D: chloride influx contributes to early repolarization in some species
but is not the primary mechanism in humans.
5 A researcher is investigating the effect of a drug that inhibits the Na+/K+ ATPase pump in the thick ascending
limb of the loop of Henle. Which of the following changes in urine composition is most likely to be observed?
A) Decreased urine osmolality and increased urine volume.
B) Increased urine osmolality and decreased urine volume.
C) Decreased urine sodium concentration and increased urine potassium concentration.
D) Increased urine calcium concentration and decreased urine magnesium concentration.
Answer: A
Rationale: Inhibition of Na+/K+ ATPase in the thick ascending limb reduces the active transport of Na+ and Cl- out
of the tubule, impairing the countercurrent multiplier system. This reduces medullary hypertonicity, leading to
decreased water reabsorption and increased urine volume (diuresis) with low osmolality. Option B is the opposite.
Option C: Na+ excretion increases, not decreases. Option D: Ca2+ and Mg2+ reabsorption in the thick ascending
limb is passive and depends on the positive lumen potential generated by Na+ reabsorption; inhibition of Na+/K+
ATPase reduces this potential, decreasing reabsorption of both Ca2+ and Mg2+, so their urine concentrations
increase, not decrease.
6 In a patient with hyperaldosteronism, which of the following laboratory findings is most consistent with the
chronic effects of aldosterone excess?
A) Hyperkalemia and metabolic acidosis.
B) Hypokalemia and metabolic alkalosis.
C) Hypernatremia and metabolic acidosis.
D) Hyponatremia and metabolic alkalosis.
Answer: B
Rationale: Aldosterone increases Na+ reabsorption and K+ and H+ excretion in the distal nephron. Chronic excess
leads to hypokalemia (from K+ wasting) and metabolic alkalosis (from H+ wasting). Option A is the opposite.
Option C: hypernatremia may occur but is less pronounced due to thirst mechanisms; metabolic acidosis is not
typical. Option D: hyponatremia is not a feature; alkalosis is correct but hyponatremia is not.
7 Which of the following correctly describes the effect of 2,3-bisphosphoglycerate (2,3-BPG) on hemoglobin's
oxygen affinity?
A) 2,3-BPG binds to oxyhemoglobin and increases its affinity for oxygen.
B) 2,3-BPG binds to deoxyhemoglobin and stabilizes the T state, decreasing oxygen affinity.
C) 2,3-BPG binds to heme iron and competitively inhibits oxygen binding.
,D) 2,3-BPG binds to the central cavity of oxyhemoglobin and promotes the R state.
Answer: B
Rationale: 2,3-BPG binds to deoxyhemoglobin (T state) in the central cavity, stabilizing the low-affinity
conformation and shifting the oxygen dissociation curve to the right, promoting oxygen release. Option A is
incorrect because 2,3-BPG binds preferentially to deoxyhemoglobin, not oxyhemoglobin, and decreases affinity.
Option C: 2,3-BPG does not bind to heme iron. Option D: binding to oxyhemoglobin is weak and does not promote
the R state.
8 A 60-year-old patient with chronic obstructive pulmonary disease (COPD) has a PaO2 of 55 mmHg and a
PaCO2 of 65 mmHg. Which of the following renal compensatory mechanisms is most likely to be activated?
A) Increased reabsorption of bicarbonate and increased excretion of hydrogen ions.
B) Decreased reabsorption of bicarbonate and decreased excretion of hydrogen ions.
C) Increased reabsorption of bicarbonate and decreased excretion of hydrogen ions.
D) Decreased reabsorption of bicarbonate and increased excretion of hydrogen ions.
Answer: A
Rationale: Chronic respiratory acidosis (high PaCO2) triggers renal compensation: the kidneys increase bicarbonate
reabsorption and hydrogen ion excretion (as NH4+ and titratable acid) to raise blood pH. Option B would worsen
acidosis. Option C: decreased H+ excretion is incorrect. Option D: decreased bicarbonate reabsorption would not
compensate for acidosis.
9 Which of the following best describes the role of the hypothalamic-pituitary-thyroid axis in regulating metabolic
rate?
A) Thyrotropin-releasing hormone (TRH) directly stimulates the thyroid to release T3 and T4.
B) Thyroid-stimulating hormone (TSH) stimulates the thyroid to produce T4, which is peripherally converted to
the more active T3.
C) T3 and T4 exert negative feedback on the anterior pituitary only, not the hypothalamus.
D) Iodide uptake by the thyroid is regulated by TSH independent of the sodium-iodide symporter.
Answer: B
Rationale: TSH from the anterior pituitary stimulates the thyroid to produce and release T4 (and some T3). T4 is
converted to the more active T3 in peripheral tissues. Option A: TRH stimulates the anterior pituitary, not directly
the thyroid. Option C: T3/T4 exert negative feedback on both the hypothalamus and anterior pituitary. Option D:
TSH increases iodide uptake via the sodium-iodide symporter, not independently.
10 A 35-year-old female presents with galactorrhea and amenorrhea. Serum prolactin is markedly elevated. Which
of the following is the most likely cause?
A) Hypothalamic tumor secreting excess dopamine.
B) Prolactin-secreting adenoma (prolactinoma).
C) Primary hypothyroidism with increased TRH.
D) Sheehan syndrome with decreased prolactin.
Answer: B
Rationale: A prolactinoma is the most common cause of hyperprolactinemia, leading to galactorrhea and
amenorrhea. Option A: dopamine inhibits prolactin release; excess dopamine would decrease prolactin. Option C:
primary hypothyroidism increases TRH, which can stimulate prolactin release, but this is less common than
prolactinoma. Option D: Sheehan syndrome (postpartum pituitary necrosis) causes decreased prolactin, not
increased.
, 11 A researcher is investigating the effect of a novel drug that selectively blocks the Na+/K+ ATPase pump on the
basolateral membrane of renal proximal tubule cells. Which of the following changes in tubular reabsorption
would be most directly expected as a result of this blockade?
A) Decreased reabsorption of sodium and water, with no change in glucose reabsorption
B) Increased reabsorption of sodium and water, with decreased reabsorption of glucose
C) Decreased reabsorption of sodium and glucose, with unchanged water reabsorption
D) Decreased reabsorption of sodium, water, and glucose
Answer: D
Rationale: The Na+/K+ ATPase pump maintains the electrochemical gradient for sodium, which drives secondary
active transport of glucose and other solutes. Blocking this pump reduces sodium reabsorption and the gradient for
glucose co-transport, leading to decreased reabsorption of sodium, water, and glucose. Option A is incorrect
because glucose reabsorption also depends on sodium gradient. Option B is incorrect because blockade decreases,
not increases, reabsorption. Option C is incorrect because water reabsorption follows sodium osmotically.
12 In a patient with a complete transection of the spinal cord at the T10 level, which of the following clinical
findings would be expected immediately after the injury?
A) Flaccid paralysis of the lower extremities with loss of deep tendon reflexes and Babinski sign present
B) Spastic paralysis of the lower extremities with hyperreflexia and Babinski sign absent
C) Flaccid paralysis of the lower extremities with loss of deep tendon reflexes and Babinski sign absent
D) Spastic paralysis of the lower extremities with hyperreflexia and Babinski sign present
Answer: C
Rationale: Immediately after a complete spinal cord transection, spinal shock occurs, characterized by flaccid
paralysis, areflexia, and loss of sensation below the level of injury. The Babinski sign is absent during spinal shock.
Option A is incorrect because Babinski sign is absent. Option B is incorrect because spasticity and hyperreflexia
develop later after resolution of spinal shock. Option D describes chronic phase findings.
13 Which of the following best explains why the resting membrane potential of a typical neuron is closer to the
equilibrium potential for potassium (E_K) than for sodium (E_Na)?
A) The membrane is more permeable to potassium at rest, and the Na+/K+ pump contributes an electrogenic
effect
B) Sodium channels are inactivated at rest, preventing sodium movement
C) Potassium is actively transported into the cell, making the inside more negative
D) Chloride ions contribute significantly to the resting potential, balancing sodium leakage
Answer: A
Rationale: At rest, the membrane is highly permeable to potassium (due to leak channels) and less permeable to
sodium. The Na+/K+ pump also contributes a small electrogenic effect (3 Na+ out, 2 K+ in), making the inside
slightly more negative. Option B is incorrect because sodium channels are closed but not inactivated at rest. Option
C is incorrect because potassium is not actively transported into the cell; the pump moves K+ in but Na+ out.
Option D is incorrect because chloride's contribution is minimal in most neurons.
14 A 45-year-old male presents with muscle weakness, fatigue, and hyperpigmentation of the skin. Laboratory
findings show hyponatremia, hyperkalemia, and low serum cortisol. Which of the following is the most likely
cause of his symptoms?
A) Primary adrenal insufficiency due to autoimmune destruction of the adrenal cortex
B) Secondary adrenal insufficiency due to pituitary adenoma
C) Cushing's disease due to excessive ACTH secretion
D) Conn's syndrome due to aldosterone-secreting adenoma
Review of Questions and Correct Detailed Answers - 139
Questions
Section 1: Anatomy and Physiology (Questions 1-19)
1 A researcher is studying the effect of a novel drug that blocks the activity of phosphofructokinase-1 (PFK-1) in
hepatocytes. Which of the following metabolic consequences is most likely to occur in these cells under aerobic
conditions?
A) Increased glycogen synthesis due to elevated glucose-6-phosphate levels.
B) Accumulation of fructose-1,6-bisphosphate and increased flux through the pentose phosphate pathway.
C) Decreased lactate production and increased gluconeogenesis from lactate.
D) Reduced ATP production and compensatory upregulation of fatty acid oxidation.
Answer: A
Rationale: PFK-1 is a key regulatory enzyme in glycolysis. Blocking it causes accumulation of upstream metabolites
like glucose-6-phosphate, which allosterically activates glycogen synthase, promoting glycogen synthesis. Option
B is incorrect because fructose-1,6-bisphosphate is downstream of PFK-1 and would decrease, not accumulate.
Option C: decreased glycolysis reduces pyruvate and thus lactate, but gluconeogenesis from lactate is not directly
stimulated. Option D: ATP production from glycolysis decreases, but fatty acid oxidation is not directly
upregulated by PFK-1 inhibition; cells may rely more on oxidative phosphorylation but not necessarily via
increased fatty acid oxidation.
2 In a patient with a complete transection of the spinal cord at the T10 level, which of the following clinical
findings is expected immediately after the injury?
A) Hyperreflexia and spasticity in the lower extremities.
B) Flaccid paralysis and loss of deep tendon reflexes below the lesion.
C) Preservation of voluntary motor function in the lower extremities but loss of sensation.
D) Babinski sign present bilaterally with intact cremasteric reflex.
Answer: B
Rationale: Immediately after spinal cord transection, spinal shock occurs, characterized by flaccid paralysis,
areflexia, and loss of sensation below the level of the lesion. Hyperreflexia and spasticity (option A) develop later,
after spinal shock resolves. Option C is incorrect because both motor and sensory functions are lost. Option D:
Babinski sign is an upper motor neuron sign that appears later, and the cremasteric reflex is lost during spinal
shock.
3 A 45-year-old individual with chronic hypertension is found to have a left ventricular hypertrophy. Which of the
following best explains the underlying physiological adaptation?
A) Increased afterload leads to eccentric hypertrophy with increased ventricular volume.
B) Increased preload leads to concentric hypertrophy with increased wall thickness.
C) Increased afterload leads to concentric hypertrophy with increased wall thickness.
D) Increased preload leads to eccentric hypertrophy with decreased wall thickness.
Answer: C
Rationale: Chronic hypertension increases afterload (the pressure the heart must overcome to eject blood). The left
ventricle adapts by concentric hypertrophy, where the wall thickens without significant chamber enlargement.
Option A is incorrect because increased afterload causes concentric, not eccentric hypertrophy. Option B: increased
,preload typically causes eccentric hypertrophy (e.g., in volume overload). Option D: eccentric hypertrophy
involves increased ventricular volume and wall thickness, not decreased.
4 Which of the following correctly describes the movement of ions during the repolarization phase of a cardiac
ventricular action potential?
A) Rapid influx of sodium ions through voltage-gated sodium channels.
B) Influx of calcium ions through L-type calcium channels.
C) Efflux of potassium ions through delayed rectifier potassium channels.
D) Influx of chloride ions through calcium-activated chloride channels.
Answer: C
Rationale: Repolarization in ventricular myocytes is primarily due to efflux of potassium ions through delayed
rectifier potassium channels (IKr and IKs). Option A describes the rapid depolarization phase (phase 0). Option B
describes the plateau phase (phase 2). Option D: chloride influx contributes to early repolarization in some species
but is not the primary mechanism in humans.
5 A researcher is investigating the effect of a drug that inhibits the Na+/K+ ATPase pump in the thick ascending
limb of the loop of Henle. Which of the following changes in urine composition is most likely to be observed?
A) Decreased urine osmolality and increased urine volume.
B) Increased urine osmolality and decreased urine volume.
C) Decreased urine sodium concentration and increased urine potassium concentration.
D) Increased urine calcium concentration and decreased urine magnesium concentration.
Answer: A
Rationale: Inhibition of Na+/K+ ATPase in the thick ascending limb reduces the active transport of Na+ and Cl- out
of the tubule, impairing the countercurrent multiplier system. This reduces medullary hypertonicity, leading to
decreased water reabsorption and increased urine volume (diuresis) with low osmolality. Option B is the opposite.
Option C: Na+ excretion increases, not decreases. Option D: Ca2+ and Mg2+ reabsorption in the thick ascending
limb is passive and depends on the positive lumen potential generated by Na+ reabsorption; inhibition of Na+/K+
ATPase reduces this potential, decreasing reabsorption of both Ca2+ and Mg2+, so their urine concentrations
increase, not decrease.
6 In a patient with hyperaldosteronism, which of the following laboratory findings is most consistent with the
chronic effects of aldosterone excess?
A) Hyperkalemia and metabolic acidosis.
B) Hypokalemia and metabolic alkalosis.
C) Hypernatremia and metabolic acidosis.
D) Hyponatremia and metabolic alkalosis.
Answer: B
Rationale: Aldosterone increases Na+ reabsorption and K+ and H+ excretion in the distal nephron. Chronic excess
leads to hypokalemia (from K+ wasting) and metabolic alkalosis (from H+ wasting). Option A is the opposite.
Option C: hypernatremia may occur but is less pronounced due to thirst mechanisms; metabolic acidosis is not
typical. Option D: hyponatremia is not a feature; alkalosis is correct but hyponatremia is not.
7 Which of the following correctly describes the effect of 2,3-bisphosphoglycerate (2,3-BPG) on hemoglobin's
oxygen affinity?
A) 2,3-BPG binds to oxyhemoglobin and increases its affinity for oxygen.
B) 2,3-BPG binds to deoxyhemoglobin and stabilizes the T state, decreasing oxygen affinity.
C) 2,3-BPG binds to heme iron and competitively inhibits oxygen binding.
,D) 2,3-BPG binds to the central cavity of oxyhemoglobin and promotes the R state.
Answer: B
Rationale: 2,3-BPG binds to deoxyhemoglobin (T state) in the central cavity, stabilizing the low-affinity
conformation and shifting the oxygen dissociation curve to the right, promoting oxygen release. Option A is
incorrect because 2,3-BPG binds preferentially to deoxyhemoglobin, not oxyhemoglobin, and decreases affinity.
Option C: 2,3-BPG does not bind to heme iron. Option D: binding to oxyhemoglobin is weak and does not promote
the R state.
8 A 60-year-old patient with chronic obstructive pulmonary disease (COPD) has a PaO2 of 55 mmHg and a
PaCO2 of 65 mmHg. Which of the following renal compensatory mechanisms is most likely to be activated?
A) Increased reabsorption of bicarbonate and increased excretion of hydrogen ions.
B) Decreased reabsorption of bicarbonate and decreased excretion of hydrogen ions.
C) Increased reabsorption of bicarbonate and decreased excretion of hydrogen ions.
D) Decreased reabsorption of bicarbonate and increased excretion of hydrogen ions.
Answer: A
Rationale: Chronic respiratory acidosis (high PaCO2) triggers renal compensation: the kidneys increase bicarbonate
reabsorption and hydrogen ion excretion (as NH4+ and titratable acid) to raise blood pH. Option B would worsen
acidosis. Option C: decreased H+ excretion is incorrect. Option D: decreased bicarbonate reabsorption would not
compensate for acidosis.
9 Which of the following best describes the role of the hypothalamic-pituitary-thyroid axis in regulating metabolic
rate?
A) Thyrotropin-releasing hormone (TRH) directly stimulates the thyroid to release T3 and T4.
B) Thyroid-stimulating hormone (TSH) stimulates the thyroid to produce T4, which is peripherally converted to
the more active T3.
C) T3 and T4 exert negative feedback on the anterior pituitary only, not the hypothalamus.
D) Iodide uptake by the thyroid is regulated by TSH independent of the sodium-iodide symporter.
Answer: B
Rationale: TSH from the anterior pituitary stimulates the thyroid to produce and release T4 (and some T3). T4 is
converted to the more active T3 in peripheral tissues. Option A: TRH stimulates the anterior pituitary, not directly
the thyroid. Option C: T3/T4 exert negative feedback on both the hypothalamus and anterior pituitary. Option D:
TSH increases iodide uptake via the sodium-iodide symporter, not independently.
10 A 35-year-old female presents with galactorrhea and amenorrhea. Serum prolactin is markedly elevated. Which
of the following is the most likely cause?
A) Hypothalamic tumor secreting excess dopamine.
B) Prolactin-secreting adenoma (prolactinoma).
C) Primary hypothyroidism with increased TRH.
D) Sheehan syndrome with decreased prolactin.
Answer: B
Rationale: A prolactinoma is the most common cause of hyperprolactinemia, leading to galactorrhea and
amenorrhea. Option A: dopamine inhibits prolactin release; excess dopamine would decrease prolactin. Option C:
primary hypothyroidism increases TRH, which can stimulate prolactin release, but this is less common than
prolactinoma. Option D: Sheehan syndrome (postpartum pituitary necrosis) causes decreased prolactin, not
increased.
, 11 A researcher is investigating the effect of a novel drug that selectively blocks the Na+/K+ ATPase pump on the
basolateral membrane of renal proximal tubule cells. Which of the following changes in tubular reabsorption
would be most directly expected as a result of this blockade?
A) Decreased reabsorption of sodium and water, with no change in glucose reabsorption
B) Increased reabsorption of sodium and water, with decreased reabsorption of glucose
C) Decreased reabsorption of sodium and glucose, with unchanged water reabsorption
D) Decreased reabsorption of sodium, water, and glucose
Answer: D
Rationale: The Na+/K+ ATPase pump maintains the electrochemical gradient for sodium, which drives secondary
active transport of glucose and other solutes. Blocking this pump reduces sodium reabsorption and the gradient for
glucose co-transport, leading to decreased reabsorption of sodium, water, and glucose. Option A is incorrect
because glucose reabsorption also depends on sodium gradient. Option B is incorrect because blockade decreases,
not increases, reabsorption. Option C is incorrect because water reabsorption follows sodium osmotically.
12 In a patient with a complete transection of the spinal cord at the T10 level, which of the following clinical
findings would be expected immediately after the injury?
A) Flaccid paralysis of the lower extremities with loss of deep tendon reflexes and Babinski sign present
B) Spastic paralysis of the lower extremities with hyperreflexia and Babinski sign absent
C) Flaccid paralysis of the lower extremities with loss of deep tendon reflexes and Babinski sign absent
D) Spastic paralysis of the lower extremities with hyperreflexia and Babinski sign present
Answer: C
Rationale: Immediately after a complete spinal cord transection, spinal shock occurs, characterized by flaccid
paralysis, areflexia, and loss of sensation below the level of injury. The Babinski sign is absent during spinal shock.
Option A is incorrect because Babinski sign is absent. Option B is incorrect because spasticity and hyperreflexia
develop later after resolution of spinal shock. Option D describes chronic phase findings.
13 Which of the following best explains why the resting membrane potential of a typical neuron is closer to the
equilibrium potential for potassium (E_K) than for sodium (E_Na)?
A) The membrane is more permeable to potassium at rest, and the Na+/K+ pump contributes an electrogenic
effect
B) Sodium channels are inactivated at rest, preventing sodium movement
C) Potassium is actively transported into the cell, making the inside more negative
D) Chloride ions contribute significantly to the resting potential, balancing sodium leakage
Answer: A
Rationale: At rest, the membrane is highly permeable to potassium (due to leak channels) and less permeable to
sodium. The Na+/K+ pump also contributes a small electrogenic effect (3 Na+ out, 2 K+ in), making the inside
slightly more negative. Option B is incorrect because sodium channels are closed but not inactivated at rest. Option
C is incorrect because potassium is not actively transported into the cell; the pump moves K+ in but Na+ out.
Option D is incorrect because chloride's contribution is minimal in most neurons.
14 A 45-year-old male presents with muscle weakness, fatigue, and hyperpigmentation of the skin. Laboratory
findings show hyponatremia, hyperkalemia, and low serum cortisol. Which of the following is the most likely
cause of his symptoms?
A) Primary adrenal insufficiency due to autoimmune destruction of the adrenal cortex
B) Secondary adrenal insufficiency due to pituitary adenoma
C) Cushing's disease due to excessive ACTH secretion
D) Conn's syndrome due to aldosterone-secreting adenoma
