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

Question

Quizplus · Accepted Answer

Extracellular calcium ions (Ca2+) are crucial for the fusion of synaptic vesicles with the presynaptic membrane, leading to the release of neurotransmitters such as acetylcholine (ACh) at the neuromuscular junction. Without extracellular Ca2+, synaptic vesicles would not fuse properly, and ACh would not be released, impairing muscle stimulation.

What Would Result from a Lack of Extracellular Ca2+ at the Neuromuscular

What Would Result from a Lack of Extracellular Ca²⁺ at the Neuromuscular