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1. A 23-year-old man presents with right arm pain after a fall. He cannot
extend his wrist. What nerve is most likely injured?
A. Median
B. Ulnar
C. Radial
D. Axillary
Radial nerve injury leads to wrist drop due to impaired innervation of the
extensor muscles of the forearm.
2. Which of the following agents inhibits dihydrofolate reductase?
A. Sulfamethoxazole
B. Trimethoprim
C. Ciprofloxacin
D. Rifampin
,Trimethoprim blocks bacterial DHFR, impairing folate synthesis.
3. A patient with an elevated mean corpuscular volume (MCV) and
neurologic symptoms likely has a deficiency in:
A. Folate
B. Vitamin B12
C. Iron
D. Vitamin C
Vitamin B12 deficiency leads to megaloblastic anemia and neurologic
symptoms due to impaired myelin synthesis.
4. A positive Trendelenburg sign indicates weakness in which muscle?
A. Vastus lateralis
B. Gluteus medius
C. Gluteus maximus
D. Piriformis
Gluteus medius (and minimus) stabilize the pelvis; their weakness causes
hip drop on the contralateral side.
5. A 68-year-old woman presents with pain over the lateral elbow.
Resisted wrist extension exacerbates the pain. What is the most likely
diagnosis?
A. Medial epicondylitis
B. Lateral epicondylitis
,C. Olecranon bursitis
D. Radial head subluxation
Lateral epicondylitis (tennis elbow) is caused by overuse of the wrist
extensors, especially the extensor carpi radialis brevis.
6. A positive Lachman test suggests injury to which structure?
A. Posterior cruciate ligament
B. Anterior cruciate ligament
C. Medial collateral ligament
D. Lateral collateral ligament
The Lachman test is specific for ACL injury, indicated by anterior translation
of the tibia.
7. Which hormone is increased in 21-hydroxylase deficiency?
A. Aldosterone
B. Cortisol
C. 17-hydroxyprogesterone
D. Dopamine
Deficiency of 21-hydroxylase leads to buildup of 17-OHP and androgen
excess.
8. A 30-year-old woman presents with exophthalmos and heat
intolerance. What is the most likely diagnosis?
A. Hashimoto thyroiditis
B. Subacute thyroiditis
, C. Graves disease
D. Toxic adenoma
Graves disease is the most common cause of hyperthyroidism with eye
findings due to autoimmune stimulation of TSH receptors.
9. A young adult is treated with isoniazid for tuberculosis.
Supplementation with which vitamin prevents peripheral neuropathy?
A. B2 (riboflavin)
B. B6 (pyridoxine)
C. B9 (folate)
D. B12 (cobalamin)
INH inhibits pyridoxine metabolism, leading to peripheral neuropathy if
not supplemented.
10. Which of the following best describes the Chapman’s reflex
point for the appendix?
A. Right 2nd intercostal space
B. Tip of the 12th rib on the right
C. Left 10th rib
D. Right T10 transverse process
Chapman point for appendix is located at the tip of the right 12th rib.
11. A 4-year-old child has epiglottitis. What is the most likely
causative organism?