KMU Past Paper Practice

MCQ 1

Question:

During examination of a normal adrenal gland, the cortex has a yellow appearance on cut section. Which structural feature best accounts for this appearance?

Options:

Correct Answer: Abundant lipid within steroid-producing cells

Explanation: Adrenal cortical cells contain abundant lipid because cholesterol is the precursor for steroid hormone synthesis, giving the cortex its characteristic yellow appearance.

MCQ 2

Question:

A patient loses circulating volume after prolonged vomiting. Renin release increases appropriately. Which mediator most directly stimulates subsequent aldosterone secretion from the adrenal cortex?

Options:

Correct Answer: Angiotensin II

Explanation: Volume depletion activates the renin–angiotensin system; angiotensin II then stimulates zona glomerulosa cells to increase aldosterone secretion.

MCQ 3

Question:

A 44-year-old woman has progressive central weight gain and proximal weakness. Her physician requests late-night salivary cortisol as part of the initial endocrine assessment. Which physiological abnormality is this test designed to identify?

Options:

Correct Answer: Loss of the normal nighttime cortisol nadir

Explanation: Normal cortisol falls to a low level late at night. Persistently elevated late-night cortisol indicates loss of normal circadian regulation and supports hypercortisolism.

MCQ 4

Question:

A patient with suspected endogenous cortisol excess undergoes measurement of urinary free cortisol collected over an extended period. What information does this investigation principally provide?

Options:

Correct Answer: Integrated cortisol production during the collection period

Explanation: Urinary free cortisol reflects cortisol production over the collection interval and helps demonstrate sustained excessive cortisol secretion.

MCQ 5

Question:

A patient with hypercortisolism has diffuse darkening of the skin and a markedly elevated plasma ACTH concentration. Which mechanism most directly explains the pigmentation?

Options:

Correct Answer: ACTH-related stimulation of melanocortin receptors

Explanation: Markedly increased ACTH-related peptides stimulate melanocortin receptors in the skin, producing hyperpigmentation and suggesting an ACTH-dependent process.

MCQ 6

Question:

A man with severe endogenous hypercortisolism develops worsening hypertension and a low serum potassium concentration. Which effect of very high cortisol concentrations best accounts for these findings?

Options:

Correct Answer: Mineralocorticoid-like action on renal sodium and potassium handling

Explanation: At high concentrations cortisol can exert mineralocorticoid-like effects, promoting sodium retention and potassium loss and thereby contributing to hypertension and hypokalaemia.

MCQ 7

Question:

A 50-year-old woman presents with facial fullness, central weight gain and easy bruising. She has used several medications for chronic inflammatory disease over the previous year. Which step is particularly important before investigating an endogenous source of cortisol excess?

Options:

Correct Answer: Review exposure to glucocorticoids by all routes

Explanation: Exogenous glucocorticoid exposure is an important cause of Cushing syndrome, so oral, injected, inhaled and topical preparations should be identified before pursuing endogenous causes.

MCQ 8

Question:

A 48-year-old man with primary hyperaldosteronism has hypertension, hypokalaemia and an increased serum bicarbonate concentration. Which renal effect most directly contributes to the acid-base abnormality?

Options:

Correct Answer: Increased distal hydrogen-ion secretion

Explanation: Aldosterone promotes hydrogen-ion secretion in the distal nephron. Excessive activity therefore favors hydrogen loss and metabolic alkalosis.

MCQ 9

Question:

A patient with primary hyperaldosteronism develops marked potassium depletion and complains of excessive thirst and frequent urination. Which mechanism best explains these symptoms?

Options:

Correct Answer: Impaired renal concentrating ability from potassium depletion

Explanation: Significant hypokalaemia impairs the kidney’s ability to concentrate urine, producing polyuria and secondary polydipsia.

MCQ 10

Question:

A 46-year-old woman with difficult-to-control hypertension is being evaluated for primary hyperaldosteronism. Her serum potassium concentration is within the reference range. Which interpretation is most appropriate?

Options:

Correct Answer: Normal potassium does not exclude primary hyperaldosteronism

Explanation: Hypokalaemia is an important clue but is not present in every patient. The diagnosis should therefore still be considered when the clinical and renin–aldosterone pattern is suggestive.

MCQ 11

Question:

A patient with resistant hypertension is being screened for autonomous aldosterone secretion. Which biochemical relationship is most useful for the initial assessment?

Options:

Correct Answer: Aldosterone relative to renin

Explanation: Primary hyperaldosteronism produces aldosterone activity that is inappropriate for the suppressed renin state, making the aldosterone-to-renin relationship useful for screening.

MCQ 12

Question:

Screening tests in a hypertensive patient suggest primary hyperaldosteronism. Which finding on subsequent physiological testing would best support autonomous aldosterone secretion?

Options:

Correct Answer: Failure of aldosterone to suppress appropriately

Explanation: Confirmatory testing demonstrates that aldosterone production remains inappropriately active when normal physiology should suppress it.

MCQ 13

Question:

A 23-year-old woman presents with acne, increasing facial hair and irregular menstrual cycles. A mild congenital adrenal steroid synthesis disorder is suspected. Which hormonal effect most directly accounts for this presentation?

Options:

Correct Answer: Excess adrenal androgen activity

Explanation: Milder congenital adrenal hyperplasia can present later with androgen excess, producing acne, hirsutism and menstrual irregularity.

MCQ 14

Question:

A male newborn with severe congenital adrenal hyperplasia is not recognized immediately after birth but later develops features of salt loss. Which feature can make the disorder less obvious initially in an affected male infant?

Options:

Correct Answer: External genitalia may appear typically male at birth

Explanation: A male infant may lack obvious genital ambiguity despite severe enzyme deficiency, so salt-wasting disease can become the first clear clinical presentation.

MCQ 15

Question:

A 61-year-old woman receiving long-term systemic glucocorticoid therapy complains of progressive visual difficulty. Which recognized adverse effect of prolonged glucocorticoid exposure should be considered?

Options:

Correct Answer: Cataract with increased intraocular pressure

Explanation: Prolonged glucocorticoid exposure can cause cataract and raise intraocular pressure, both important long-term adverse effects.

MCQ 16

Question:

During interpretation of a cortisol measurement, a student recalls that endogenous cortisol circulates largely bound to a specific plasma protein. Which protein is most important for this transport?

Options:

Correct Answer: Corticosteroid-binding globulin

Explanation: Endogenous cortisol circulates largely protein-bound, particularly to corticosteroid-binding globulin, with only a smaller free fraction being biologically active.

MCQ 17

Question:

A patient receiving aminoglutethimide for suppression of adrenal steroid synthesis develops new neurological complaints after starting therapy. Which adverse effect is most consistent with this drug?

Options:

Correct Answer: Sedation and dizziness

Explanation: Aminoglutethimide may cause sedation and dizziness, along with rash and excessive adrenal suppression, which limits its clinical use.

MCQ 18

Question:

A woman with endogenous Cushing syndrome is treated with mifepristone. She later develops abnormal uterine bleeding. Which pharmacological property most directly explains this adverse effect?

Options:

Correct Answer: Antagonism of progesterone receptors

Explanation: Mifepristone blocks both glucocorticoid and progesterone receptors. Its antiprogestational activity can produce endometrial effects and uterine bleeding.

MCQ 19

Question:

A patient receiving ketoconazole for hypercortisolism is prescribed another medication that undergoes extensive hepatic metabolism. Why should clinically important drug interactions be considered?

Options:

Correct Answer: Ketoconazole inhibits hepatic cytochrome P450 enzymes

Explanation: Ketoconazole inhibits several CYP enzymes involved in steroidogenesis and hepatic drug metabolism, creating clinically important interaction potential.

MCQ 20

Question:

A patient with Cushing syndrome is started on metyrapone. Cortisol concentrations fall, but blood pressure rises further and serum potassium decreases. Which change most directly explains these new findings?

Options:

Correct Answer: Accumulation of mineralocorticoid-active steroid precursors

Explanation: Metyrapone blocks 11β-hydroxylase, allowing upstream precursors with mineralocorticoid activity to accumulate and potentially worsen hypertension and hypokalaemia.