Question
A: In botulism, the patient presents with blurring of vision and difficulty to sallow R: The botulinum toxin affects the Parasympathetic nerves
Answer
- [x] c) A is true but R is false
Assertion is true: botulism does indeed present with symptoms including blurring of vision (diplopia) and difficulty swallowing (dysphagia), among other cranial nerve palsies and descending flaccid paralysis. Reason is false: botulinum toxin acts on the peripheral cholinergic (motor and autonomic) nerve terminals by blocking acetylcholine release at the neuromuscular junction (and at autonomic cholinergic synapses) — it does not selectively affect “parasympathetic nerves” as a distinct/isolated target; rather, it blocks cholinergic transmission broadly at motor endplates (producing the flaccid paralysis) and at parasympathetic postganglionic synapses (contributing to autonomic symptoms such as dry mouth and blurred vision from impaired pupillary/accommodation reflexes) — the mechanism is via blockade of acetylcholine release, not a parasympathetic-specific effect, making the reason as stated an inaccurate/incomplete characterization of the toxin’s mechanism.