During the contraction phase of a muscle twitch,

A. the action potential travels down the T tubule.
B. actin-myosin cross-bridges form.
C. acetylcholine stimulates the pre-synaptic terminal.
D. Ca2+ are transported back to the sarcoplasmic reticulum.
E. Na+ diffuse into the muscle fiber.


Answer: B

Anatomy & Physiology

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