Immunology USMLE Step 1 Practice Question
A 62-year-old man with no recent medical care presents with progressive jaw stiffness and painful muscle spasms beginning one week after a puncture wound to his foot from a barn nail. Vital signs show BP 145/92, HR 98, RR 16, temperature 37.8°C, SpO2 98% on room air. Serum electrolytes are normal. He denies recent antibiotic use. Which of the following best explains the neurologic manifestations of this infection?
Answer choices
- ADirect invasion of the central nervous system with purulent meningitis
- BBlockade of release of inhibitory neurotransmitters from spinal interneuronsCorrect answer
- CActivation of muscarinic receptors in skeletal muscle
- DBlockade of acetylcholine release at the neuromuscular junction
- EDemyelination of peripheral motor nerves by autoimmune attack
- FInhibition of gamma-aminobutyric acid synthesis in the cerebral cortex
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