NCCAOM Biomedicine and Diagnosis 2 — Questions and Answers
Question 1: A patient presents with a serum TSH of 0.1 mIU/L and elevated free T4. Which condition does this most likely indicate?
- Hypothyroidism
- Hyperthyroidism (Correct answer)
- Euthyroid sick syndrome
- Hashimoto's thyroiditis
Correct answer: Hyperthyroidism
A suppressed TSH with elevated free T4 is the hallmark of hyperthyroidism, where excess thyroid hormone feeds back to suppress pituitary TSH secretion.
Question 2: Which cranial nerve is responsible for the afferent limb of the corneal reflex?
- CN III (Oculomotor)
- CN V1 (Ophthalmic branch of Trigeminal) (Correct answer)
- CN VII (Facial)
- CN VI (Abducens)
Correct answer: CN V1 (Ophthalmic branch of Trigeminal)
The ophthalmic branch of the trigeminal nerve (CN V1) carries sensory input from the cornea, forming the afferent limb of the corneal reflex.
Question 3: Kussmaul breathing is a compensatory mechanism most associated with which acid-base disturbance?
- Metabolic alkalosis
- Respiratory acidosis
- Metabolic acidosis (Correct answer)
- Respiratory alkalosis
Correct answer: Metabolic acidosis
Kussmaul breathing (deep, rapid respirations) is a respiratory compensation for metabolic acidosis, eliminating CO2 to raise blood pH.
Question 4: A positive Murphy's sign on physical examination is most indicative of inflammation of which organ?
- Spleen
- Liver
- Gallbladder (Correct answer)
- Pancreas
Correct answer: Gallbladder
Murphy's sign—inspiratory arrest during deep palpation of the right upper quadrant—indicates acute cholecystitis (gallbladder inflammation).
Question 5: Which laboratory finding is most specific for acute myocardial infarction?
- Elevated CK-MM
- Elevated troponin I (Correct answer)
- Elevated LDH
- Elevated myoglobin
Correct answer: Elevated troponin I
Cardiac troponin I is highly specific and sensitive for myocardial injury and is the preferred biomarker for diagnosing acute MI.
Question 6: The process by which a hollow organ's pain is perceived at a distant skin surface is called:
- Hyperalgesia
- Referred pain (Correct answer)
- Allodynia
- Central sensitization
Correct answer: Referred pain
Referred pain occurs when visceral afferent fibers converge on the same spinal segments as somatic fibers, causing pain to be perceived in a remote skin area.
Question 7: Which of the following is the primary buffer system in the blood that maintains pH homeostasis?
- Phosphate buffer system
- Protein buffer system
- Bicarbonate-carbonic acid buffer system (Correct answer)
- Hemoglobin buffer system
Correct answer: Bicarbonate-carbonic acid buffer system
The bicarbonate-carbonic acid system is the most important extracellular buffer in blood, regulated by both the lungs (CO2) and kidneys (HCO3−).
NCCAOM Biomedicine and Diagnosis 2
A patient presents with a serum TSH of 0.1 mIU/L and elevated free T4.
Which condition does this most likely indicate?