PHYSIOLOGY
MUSCLE CONTRACTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Which occurs first ____ neuromuscular junction action or sliding filament action.
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Neuromuscular junction action
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Sliding filament action
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both happen at the same time
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they have nothing to do with eachother
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Explanation:
Detailed explanation-1: -Skeletal muscle contraction begins first at the neuromuscular junction, which is the synapse between a motoneuron and a muscle fiber. Propagation of action potentials to the motoneuron and subsequent depolarization results in the opening of voltage-gated calcium (Ca2+) channels of the presynaptic membrane.
Detailed explanation-2: -When an action potential reaches a neuromuscular junction, it causes acetylcholine to be released into this synapse. The acetylcholine binds to the nicotinic receptors concentrated on the motor end plate, a specialized area of the muscle fibre’s post-synaptic membrane.
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