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

question 227

Multiple Choice

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.

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Definitions:

Axon

A long, slender projection of a nerve cell, or neuron, that typically conducts electrical impulses away from the neuron's cell body.

Neuron

A specialized cell transmitting nerve impulses; a nerve cell.

Terminal Branches

The ends of axons in the nervous system, responsible for releasing neurotransmitters to send signals to other neurons or muscles.

Autonomic Nervous System

The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions, such as the heart rate, digestion, respiratory rate, pupillary response, and more.