What would result from a lack of extracellular Ca2+ at the neuromuscular junction?

A. Synaptic vesicles would fail to fuse and ACh would not be released.
B. The neuron must use its intracellular Ca2+ to make the vesicles fuse.
C. Potassium ions are used in place of Ca2+ to ensure the vesicles fuse.
D. Nothing would happen because extracellular Ca2+ does not play a role in muscle stimulation.
E. Excessive synaptic vesicles would fuse and release too much ACh, overstimulating the myofiber.


Answer: A

Anatomy & Physiology

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