This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Vecuronium acts on 
Select and explain. 
A. Cerebral cortex, B. Myoneural junction, C. Muscle fibres, D. Spinal cord
B: Myoneural junction
Answer: B: Myoneural junction 
Explanation: Vecuronium is a non-depolarizing neuromuscular blocking agent.
It acts on the nicotinic receptor at neuromuscular junctions and blocks the depolarization by inhibiting Na+ channels.