NCCAOM Biomedicine Board Ultimate Exam
**Question 1. Which of the following structures is the primary site of erythropoiesis in adults?**
A) Spleen
B) Liver
C) Bone marrow
D) Lymph nodes
Answer: C
Explanation: In adults, red blood cell production occurs mainly in the red (hematopoietic) marrow of
long bones, ribs, pelvis, and vertebrae.
**Question 2. The primary action of the hormone aldosterone is to:**
A) Increase renal calcium excretion
B) Decrease sodium reabsorption in the distal tubule
C) Increase sodium reabsorption and potassium secretion in the distal nephron
D) Stimulate antidiuretic hormone release
Answer: C
Explanation: Aldosterone binds to receptors in the distal tubule and collecting duct, promoting Na⁺
reabsorption and K⁺ secretion, thereby raising blood volume and pressure.
**Question 3. Which cranial nerve is responsible for the afferent limb of the corneal blink reflex?**
A) CN III
B) CN V
C) CN VII
D) CN X
Answer: B
Explanation: The ophthalmic branch (V1) of the trigeminal nerve (CN V) carries sensory input from the
cornea to the brainstem, initiating the blink reflex.
**Question 4. A 45-year-old patient presents with pain on resisted dorsiflexion of the foot and a positive
Thompson test. Which structure is most likely injured?**
A) Gastrocnemius muscle
, NCCAOM Biomedicine Board Ultimate Exam
B) Achilles tendon
C) Plantar fascia
D) Peroneus longus tendon
Answer: B
Explanation: The Thompson test assesses the integrity of the Achilles tendon; lack of plantar-flexion
when the calf is squeezed indicates rupture.
**Question 5. Which of the following best describes the “Hering-Breuer reflex”?**
A) Inhibition of inspiration by stretch receptors in the bronchi
B) Stimulation of diaphragm contraction by chemoreceptors
C) Reflex tachycardia during hypoxia
D) Vasodilation of pulmonary arteries during exercise
Answer: A
Explanation: Pulmonary stretch receptors activated by lung inflation send signals via the vagus to inhibit
further inspiratory effort, preventing over-inflation.
**Question 6. In the cardiac cycle, the “isovolumetric contraction” phase occurs:**
A) After the aortic valve opens
B) When both AV valves are closed and the ventricles begin to contract
C) During rapid ventricular filling
D) When the mitral valve opens
Answer: B
Explanation: Isovolumetric contraction is the period after the AV valves close and before the semilunar
valves open; ventricular pressure rises without volume change.
**Question 7. Which of the following is the most common cause of secondary hypertension?**
A) Essential hypertension
B) Renal artery stenosis
C) Pheochromocytoma
D) Cushing’s syndrome
, NCCAOM Biomedicine Board Ultimate Exam
Answer: B
Explanation: Renovascular hypertension due to renal artery stenosis is the leading identifiable secondary
cause, accounting for up to 5% of hypertensive patients.
**Question 8. A patient with type 2 diabetes presents with a fasting blood glucose of 130 mg/dL and an
HbA1c of 7.2 %. According to ADA criteria, this patient is classified as:**
A) Normal glucose tolerance
B) Prediabetes
C) Diabetes mellitus
D) Impaired fasting glucose
Answer: C
Explanation: An HbA1c ≥ 6.5 % or fasting glucose ≥ 126 mg/dL meets the diagnostic threshold for
diabetes.
**Question 9. Which of the following antibiotics is a bacteriostatic agent that inhibits protein synthesis
by binding to the 30S ribosomal subunit?**
A) Vancomycin
B] Ciprofloxacin
C) Tetracycline
D) Ampicillin
Answer: C
Explanation: Tetracyclines bind the 30S subunit, blocking the attachment of aminoacyl-tRNA, resulting in
bacteriostatic inhibition of protein synthesis.
**Question 10. The “McMurray test” is used to assess integrity of which knee structure?**
A) Medial collateral ligament
B) Posterior cruciate ligament
C) Meniscus
D) Anterior cruciate ligament
Answer: C
, NCCAOM Biomedicine Board Ultimate Exam
Explanation: The test involves flexing, rotating, and extending the knee; a click or pain suggests a
meniscal tear.
**Question 11. Which of the following best describes the mechanism of action of statins?**
A) Inhibit HMG-CoA reductase, decreasing hepatic cholesterol synthesis
B) Increase LDL receptor activity by up-regulating PCSK9
C) Block cholesterol absorption in the intestine
D) Activate peroxisome proliferator-activated receptor-α (PPAR-α)
Answer: A
Explanation: Statins competitively inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol
biosynthesis, leading to up-regulation of hepatic LDL receptors.
**Question 12. In the autonomic nervous system, the neurotransmitter released from post-ganglionic
parasympathetic fibers is:**
A) Norepinephrine
B) Epinephrine
C) Acetylcholine
D) Dopamine
Answer: C
Explanation: Parasympathetic post-ganglionic neurons release acetylcholine onto target organs,
mediating “rest-and-digest” effects.
**Question 13. A 30-year-old male presents with a bull’s-eye rash on the trunk and a history of recent
camping. Which organism is most likely responsible?**
A) Borrelia burgdorferi
B) Rickettsia rickettsii
C) Ehrlichia chaffeensis
D) Bartonella henselae
Answer: B
Explanation: Rocky Mountain spotted fever, caused by Rickettsia rickettsii, typically presents with a
maculopapular rash that may become petechial (“bull’s-eye”) and is associated with tick exposure.
**Question 1. Which of the following structures is the primary site of erythropoiesis in adults?**
A) Spleen
B) Liver
C) Bone marrow
D) Lymph nodes
Answer: C
Explanation: In adults, red blood cell production occurs mainly in the red (hematopoietic) marrow of
long bones, ribs, pelvis, and vertebrae.
**Question 2. The primary action of the hormone aldosterone is to:**
A) Increase renal calcium excretion
B) Decrease sodium reabsorption in the distal tubule
C) Increase sodium reabsorption and potassium secretion in the distal nephron
D) Stimulate antidiuretic hormone release
Answer: C
Explanation: Aldosterone binds to receptors in the distal tubule and collecting duct, promoting Na⁺
reabsorption and K⁺ secretion, thereby raising blood volume and pressure.
**Question 3. Which cranial nerve is responsible for the afferent limb of the corneal blink reflex?**
A) CN III
B) CN V
C) CN VII
D) CN X
Answer: B
Explanation: The ophthalmic branch (V1) of the trigeminal nerve (CN V) carries sensory input from the
cornea to the brainstem, initiating the blink reflex.
**Question 4. A 45-year-old patient presents with pain on resisted dorsiflexion of the foot and a positive
Thompson test. Which structure is most likely injured?**
A) Gastrocnemius muscle
, NCCAOM Biomedicine Board Ultimate Exam
B) Achilles tendon
C) Plantar fascia
D) Peroneus longus tendon
Answer: B
Explanation: The Thompson test assesses the integrity of the Achilles tendon; lack of plantar-flexion
when the calf is squeezed indicates rupture.
**Question 5. Which of the following best describes the “Hering-Breuer reflex”?**
A) Inhibition of inspiration by stretch receptors in the bronchi
B) Stimulation of diaphragm contraction by chemoreceptors
C) Reflex tachycardia during hypoxia
D) Vasodilation of pulmonary arteries during exercise
Answer: A
Explanation: Pulmonary stretch receptors activated by lung inflation send signals via the vagus to inhibit
further inspiratory effort, preventing over-inflation.
**Question 6. In the cardiac cycle, the “isovolumetric contraction” phase occurs:**
A) After the aortic valve opens
B) When both AV valves are closed and the ventricles begin to contract
C) During rapid ventricular filling
D) When the mitral valve opens
Answer: B
Explanation: Isovolumetric contraction is the period after the AV valves close and before the semilunar
valves open; ventricular pressure rises without volume change.
**Question 7. Which of the following is the most common cause of secondary hypertension?**
A) Essential hypertension
B) Renal artery stenosis
C) Pheochromocytoma
D) Cushing’s syndrome
, NCCAOM Biomedicine Board Ultimate Exam
Answer: B
Explanation: Renovascular hypertension due to renal artery stenosis is the leading identifiable secondary
cause, accounting for up to 5% of hypertensive patients.
**Question 8. A patient with type 2 diabetes presents with a fasting blood glucose of 130 mg/dL and an
HbA1c of 7.2 %. According to ADA criteria, this patient is classified as:**
A) Normal glucose tolerance
B) Prediabetes
C) Diabetes mellitus
D) Impaired fasting glucose
Answer: C
Explanation: An HbA1c ≥ 6.5 % or fasting glucose ≥ 126 mg/dL meets the diagnostic threshold for
diabetes.
**Question 9. Which of the following antibiotics is a bacteriostatic agent that inhibits protein synthesis
by binding to the 30S ribosomal subunit?**
A) Vancomycin
B] Ciprofloxacin
C) Tetracycline
D) Ampicillin
Answer: C
Explanation: Tetracyclines bind the 30S subunit, blocking the attachment of aminoacyl-tRNA, resulting in
bacteriostatic inhibition of protein synthesis.
**Question 10. The “McMurray test” is used to assess integrity of which knee structure?**
A) Medial collateral ligament
B) Posterior cruciate ligament
C) Meniscus
D) Anterior cruciate ligament
Answer: C
, NCCAOM Biomedicine Board Ultimate Exam
Explanation: The test involves flexing, rotating, and extending the knee; a click or pain suggests a
meniscal tear.
**Question 11. Which of the following best describes the mechanism of action of statins?**
A) Inhibit HMG-CoA reductase, decreasing hepatic cholesterol synthesis
B) Increase LDL receptor activity by up-regulating PCSK9
C) Block cholesterol absorption in the intestine
D) Activate peroxisome proliferator-activated receptor-α (PPAR-α)
Answer: A
Explanation: Statins competitively inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol
biosynthesis, leading to up-regulation of hepatic LDL receptors.
**Question 12. In the autonomic nervous system, the neurotransmitter released from post-ganglionic
parasympathetic fibers is:**
A) Norepinephrine
B) Epinephrine
C) Acetylcholine
D) Dopamine
Answer: C
Explanation: Parasympathetic post-ganglionic neurons release acetylcholine onto target organs,
mediating “rest-and-digest” effects.
**Question 13. A 30-year-old male presents with a bull’s-eye rash on the trunk and a history of recent
camping. Which organism is most likely responsible?**
A) Borrelia burgdorferi
B) Rickettsia rickettsii
C) Ehrlichia chaffeensis
D) Bartonella henselae
Answer: B
Explanation: Rocky Mountain spotted fever, caused by Rickettsia rickettsii, typically presents with a
maculopapular rash that may become petechial (“bull’s-eye”) and is associated with tick exposure.
