PHYSIOLOGY
GENERAL PHYSIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Which of these occurs first during a muscle contraction?
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The nerve signal reaches the neuromuscular junction
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Ach is released and opens Na ion channels
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The sarcomere shortens
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The myosin binds to the actin
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Explanation:
Detailed explanation-1: -When the nervous system signal reaches the neuromuscular junction a chemical message is released by the motor neuron. The chemical message, a neurotransmitter called acetylcholine, binds to receptors on the outside of the muscle fiber. That starts a chemical reaction within the muscle.
Detailed explanation-2: -The arrival of a nerve impulse at the neuromuscular junction causes thousands of tiny vesicles (pouches) filled with a neurotransmitter called acetylcholine to be released from the axon tip into the synapse.
There is 1 question to complete.