The neurotransmitter released at the neuromuscular junction of skeletal muscle is
Correct answer: C. acetylcholine
- A. noradrenaline
- B. dopamine
- C. acetylcholine
- D. GABA
Explanation
Acetylcholine diffuses across the synaptic cleft and depolarises the sarcolemma, and the resulting action potential spreads down the T tubules to release calcium. The enzyme cholinesterase then destroys it quickly, so each nerve impulse produces one twitch rather than continuous contraction. Nerve gases and some insecticides are lethal because they block that enzyme.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Muscle Contraction
Muscle contraction is explained by the sliding filament model, in which myosin heads pull actin filaments within sarcomeres using ATP. The topic covers calcium, troponin, tropomyosin, the neuromuscular junction and relaxation, with attention to how filament length stays almost constant while the sarcomere shortens.
Practise Support and Movement
738 free Support and Movement MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.