NBME CBSE ACTUAL TEST Comprehensive
Examination Preparation Resource
Question 1: A 62-year-old woman with osteoporosis is prescribed a
bisphosphonate. The expected beneficial effect of the drug is due to which of
the following?
A. Increased osteoblast activity
B. Decreased osteoclast activity
C. Increased calcium absorption
D. Decreased parathyroid hormone secretion
Answer: B
Rationale: Bisphosphonates are pyrophosphate analogs that bind to hydroxyapatite in bone and
are taken up by osteoclasts during bone resorption. They inhibit osteoclast activity by impairing the
osteoclast's ability to form the ruffled border, leading to decreased bone resorption and increased
bone mineral density. This mechanism reduces the risk of fractures in patients with osteoporosis.
Question 2: A cohort study of elderly women examining the relationship
between regular exercise and hip fractures reports a relative risk ratio of 1.2
(95% confidence interval 1.1 to 1.8). Which of the following is the most
appropriate conclusion about the effect of exercise on the risk of hip fracture?
A. Exercise significantly decreases the risk of hip fracture
B. Exercise is associated with a statistically significant overall increase in
risk
C. Exercise has no effect on hip fracture risk
D. The study lacks sufficient power to draw conclusions
Answer: B
Rationale: A relative risk (RR) of 1.2 indicates a 20% increased risk of hip fractures among those
who exercise regularly compared to those who do not. Since the 95% confidence interval (1.1 to
1.8) does not include 1.0, the result is statistically significant at the p<0.05 level. This suggests that
regular exercise is associated with a statistically significant increase in hip fracture risk in this
population.
,Question 3: A 52-year-old man with a history of hypertension presents to the
emergency department with chest pain radiating to his jaw while shoveling
snow. His pulse is 80/min and blood pressure is 130/70. He is diagnosed with
unstable angina. The most immediate treatment's mechanism of action is:
A. Decreased platelet aggregation
B. Increased nitric oxide concentration
C. Beta-1 receptor blockade
D. Calcium channel blockade
Answer: B
Rationale: The most immediate treatment for unstable angina is sublingual nitroglycerin, which is
converted to nitric oxide (NO) in the vascular smooth muscle. NO activates guanylate cyclase,
increasing cyclic GMP, leading to vasodilation of coronary and peripheral vessels. This reduces
preload and afterload, decreasing myocardial oxygen demand and relieving chest pain.
Question 4: A 49-year-old woman with coronary artery disease has a blood
pressure of 140/90 mmHg. Laboratory studies show total cholesterol of 220
mg/dL, LDL of 190 mg/dL, and triglycerides of 350 mg/dL. She is treated with
atorvastatin and losartan. Which of the following effects on HDL and
triglycerides is expected?
A. HDL increased, Triglycerides increased
B. HDL increased, Triglycerides decreased
C. HDL decreased, Triglycerides increased
D. HDL decreased, Triglycerides decreased
Answer: B
Rationale: Atorvastatin (a statin) decreases LDL cholesterol and triglycerides while modestly
increasing HDL cholesterol. Losartan (an angiotensin receptor blocker) has neutral effects on lipid
profiles. The expected response to atorvastatin therapy includes a 20-50% reduction in LDL, 10-
30% reduction in triglycerides, and 5-10% increase in HDL.
Question 5: During a clinical study examining the effects of exercise, the
average pulse is 175/min. Compared with measurement before the exercise
session, which of the following is most likely decreased?
,A. Cardiac output
B. Stroke volume
C. Total peripheral resistance
D. Oxygen consumption
Answer: C
Rationale: During exercise, sympathetic nervous system activation causes vasodilation in skeletal
muscle beds and vasoconstriction in non-essential vascular beds. However, the overall effect is a
decrease in total peripheral resistance (TPR) due to the large vascular bed of active skeletal muscle.
This allows increased blood flow to working muscles. Cardiac output, stroke volume, and oxygen
consumption all increase during exercise.
Question 6: A 65-year-old man presents for a health maintenance
examination. He lives in a single-family home with his cat and dog. He spends
much of his time in his basement woodworking shop. This patient is at
increased risk for lung cancer due to which of the following environmental
exposures?
A. Asbestos
B. Radon
C. Secondhand smoke
D. Pet dander
Answer: B
Rationale: Radon is a colorless, odorless, radioactive gas that is the second leading cause of lung
cancer after smoking. It can accumulate in basements and enclosed spaces, particularly in areas
with high soil radon concentrations. Prolonged exposure to radon decay products increases the risk
of lung cancer. Asbestos is associated with mesothelioma and lung cancer but is more commonly an
occupational exposure.
Question 7: A 54-year-old man with a 40-year history of type 1 diabetes
mellitus is receiving hemodialysis for end-stage renal disease while awaiting a
kidney transplant. He receives a drug that induces reticulocyte release from
bone marrow and stimulates a cytokine receptor that signals through the
Jak/Stat pathway. This drug is most likely:
A. Granulocyte colony-stimulating factor
B. Erythropoietin
, C. Thrombopoietin
D. Interleukin-2
Answer: B
Rationale: Erythropoietin (EPO) is a glycoprotein hormone produced by the kidneys that
stimulates erythropoiesis. It binds to the erythropoietin receptor (EPO-R) on erythroid progenitor
cells, activating the JAK2/STAT5 signaling pathway. This leads to proliferation and differentiation
of erythroid precursors and release of reticulocytes from the bone marrow. Patients with end-stage
renal disease have decreased EPO production and require exogenous EPO therapy to treat anemia.
Question 8: A 44-year-old woman presents with a 10-month history of wide
red streaks over her lower trunk (striae) and weight gain in her face (moon
facies). Which additional findings would most likely be present?
A. Hypotension and weight loss
B. Hypertension and muscle weakness
C. Hyperpigmentation and hyponatremia
D. Hypothermia and bradycardia
Answer: B
Rationale: The clinical presentation of striae, moon facies, and weight gain is characteristic of
Cushing's syndrome (chronic cortisol excess). Additional findings include hypertension (due to
mineralocorticoid effects), proximal muscle weakness, central obesity, buffalo hump, easy bruising,
and hyperglycemia. Hypotension, weight loss, and hyperpigmentation are features of Addison's
disease (adrenal insufficiency).
Question 9: A 73-year-old man presents with diffuse weakness and tingling of
his arms and legs. Sensation of vibration and position is decreased in all
extremities. Which vitamin deficiency is most likely responsible for these
findings?
A. Vitamin B1 (thiamine)
B. Vitamin B12 (cyanocobalamin)
C. Vitamin B6 (pyridoxine)
D. Vitamin E
Answer: B
Examination Preparation Resource
Question 1: A 62-year-old woman with osteoporosis is prescribed a
bisphosphonate. The expected beneficial effect of the drug is due to which of
the following?
A. Increased osteoblast activity
B. Decreased osteoclast activity
C. Increased calcium absorption
D. Decreased parathyroid hormone secretion
Answer: B
Rationale: Bisphosphonates are pyrophosphate analogs that bind to hydroxyapatite in bone and
are taken up by osteoclasts during bone resorption. They inhibit osteoclast activity by impairing the
osteoclast's ability to form the ruffled border, leading to decreased bone resorption and increased
bone mineral density. This mechanism reduces the risk of fractures in patients with osteoporosis.
Question 2: A cohort study of elderly women examining the relationship
between regular exercise and hip fractures reports a relative risk ratio of 1.2
(95% confidence interval 1.1 to 1.8). Which of the following is the most
appropriate conclusion about the effect of exercise on the risk of hip fracture?
A. Exercise significantly decreases the risk of hip fracture
B. Exercise is associated with a statistically significant overall increase in
risk
C. Exercise has no effect on hip fracture risk
D. The study lacks sufficient power to draw conclusions
Answer: B
Rationale: A relative risk (RR) of 1.2 indicates a 20% increased risk of hip fractures among those
who exercise regularly compared to those who do not. Since the 95% confidence interval (1.1 to
1.8) does not include 1.0, the result is statistically significant at the p<0.05 level. This suggests that
regular exercise is associated with a statistically significant increase in hip fracture risk in this
population.
,Question 3: A 52-year-old man with a history of hypertension presents to the
emergency department with chest pain radiating to his jaw while shoveling
snow. His pulse is 80/min and blood pressure is 130/70. He is diagnosed with
unstable angina. The most immediate treatment's mechanism of action is:
A. Decreased platelet aggregation
B. Increased nitric oxide concentration
C. Beta-1 receptor blockade
D. Calcium channel blockade
Answer: B
Rationale: The most immediate treatment for unstable angina is sublingual nitroglycerin, which is
converted to nitric oxide (NO) in the vascular smooth muscle. NO activates guanylate cyclase,
increasing cyclic GMP, leading to vasodilation of coronary and peripheral vessels. This reduces
preload and afterload, decreasing myocardial oxygen demand and relieving chest pain.
Question 4: A 49-year-old woman with coronary artery disease has a blood
pressure of 140/90 mmHg. Laboratory studies show total cholesterol of 220
mg/dL, LDL of 190 mg/dL, and triglycerides of 350 mg/dL. She is treated with
atorvastatin and losartan. Which of the following effects on HDL and
triglycerides is expected?
A. HDL increased, Triglycerides increased
B. HDL increased, Triglycerides decreased
C. HDL decreased, Triglycerides increased
D. HDL decreased, Triglycerides decreased
Answer: B
Rationale: Atorvastatin (a statin) decreases LDL cholesterol and triglycerides while modestly
increasing HDL cholesterol. Losartan (an angiotensin receptor blocker) has neutral effects on lipid
profiles. The expected response to atorvastatin therapy includes a 20-50% reduction in LDL, 10-
30% reduction in triglycerides, and 5-10% increase in HDL.
Question 5: During a clinical study examining the effects of exercise, the
average pulse is 175/min. Compared with measurement before the exercise
session, which of the following is most likely decreased?
,A. Cardiac output
B. Stroke volume
C. Total peripheral resistance
D. Oxygen consumption
Answer: C
Rationale: During exercise, sympathetic nervous system activation causes vasodilation in skeletal
muscle beds and vasoconstriction in non-essential vascular beds. However, the overall effect is a
decrease in total peripheral resistance (TPR) due to the large vascular bed of active skeletal muscle.
This allows increased blood flow to working muscles. Cardiac output, stroke volume, and oxygen
consumption all increase during exercise.
Question 6: A 65-year-old man presents for a health maintenance
examination. He lives in a single-family home with his cat and dog. He spends
much of his time in his basement woodworking shop. This patient is at
increased risk for lung cancer due to which of the following environmental
exposures?
A. Asbestos
B. Radon
C. Secondhand smoke
D. Pet dander
Answer: B
Rationale: Radon is a colorless, odorless, radioactive gas that is the second leading cause of lung
cancer after smoking. It can accumulate in basements and enclosed spaces, particularly in areas
with high soil radon concentrations. Prolonged exposure to radon decay products increases the risk
of lung cancer. Asbestos is associated with mesothelioma and lung cancer but is more commonly an
occupational exposure.
Question 7: A 54-year-old man with a 40-year history of type 1 diabetes
mellitus is receiving hemodialysis for end-stage renal disease while awaiting a
kidney transplant. He receives a drug that induces reticulocyte release from
bone marrow and stimulates a cytokine receptor that signals through the
Jak/Stat pathway. This drug is most likely:
A. Granulocyte colony-stimulating factor
B. Erythropoietin
, C. Thrombopoietin
D. Interleukin-2
Answer: B
Rationale: Erythropoietin (EPO) is a glycoprotein hormone produced by the kidneys that
stimulates erythropoiesis. It binds to the erythropoietin receptor (EPO-R) on erythroid progenitor
cells, activating the JAK2/STAT5 signaling pathway. This leads to proliferation and differentiation
of erythroid precursors and release of reticulocytes from the bone marrow. Patients with end-stage
renal disease have decreased EPO production and require exogenous EPO therapy to treat anemia.
Question 8: A 44-year-old woman presents with a 10-month history of wide
red streaks over her lower trunk (striae) and weight gain in her face (moon
facies). Which additional findings would most likely be present?
A. Hypotension and weight loss
B. Hypertension and muscle weakness
C. Hyperpigmentation and hyponatremia
D. Hypothermia and bradycardia
Answer: B
Rationale: The clinical presentation of striae, moon facies, and weight gain is characteristic of
Cushing's syndrome (chronic cortisol excess). Additional findings include hypertension (due to
mineralocorticoid effects), proximal muscle weakness, central obesity, buffalo hump, easy bruising,
and hyperglycemia. Hypotension, weight loss, and hyperpigmentation are features of Addison's
disease (adrenal insufficiency).
Question 9: A 73-year-old man presents with diffuse weakness and tingling of
his arms and legs. Sensation of vibration and position is decreased in all
extremities. Which vitamin deficiency is most likely responsible for these
findings?
A. Vitamin B1 (thiamine)
B. Vitamin B12 (cyanocobalamin)
C. Vitamin B6 (pyridoxine)
D. Vitamin E
Answer: B
