Question

Why does a skeletal muscle cell need a neuromuscular junction as a component part?

Skeletal muscle fibers are voluntary and thus must be stimulated by a neural impulse before they will contract.

Through the neuron, the brain tells the muscle cell what proteins to produce and what wastes to pump out of the cell.

The muscle cell needs to be told when to divide, such as when a person is exercising and needs more muscle.

A neuron provides the necessary nutrients such as ATP that the muscle cell needs in order to contract.

Answer 1

Skeletal muscle are voluntary and must be stimulated by a neural impulse before they contract.

The neuromuscular junction is the contact made by the terminal branches of the axon with the muscle fiber.

Skeletal muscle fibers are richly innervated by motor neurons that originate in the spinal cord or brainstem. The axons of the neurons branch as they near the muscle, giving rise to twigs or terminal branches that end on individual muscle fiber.

The nature of muscle contraction is determined by the number of motor neuron endings as well as by the number of specific types of muscle fibers that are depolarized. Although depolarization of a muscle fiber at a single neuromuscular junction is characterized as an “all-or-none” phenomenon, not all nerve terminals discharge at once, which allows a graded response to the contractile stimulus.