Question

Most muscles are joined by hundreds or even thousands of nerve fibers of the efferent (motor) nervous system. The contact between the end point of the axon of one motor-neuron and the sarolemma of the muscle is called:

A)
Reticulum switches

B)
Cross Bridges

C)
Motor Endplate

D)
Motor muscle

Answer 1

The contact point between a motor neuron axon's end and the muscle's sarcolemma is known as the motor endplate. This site is key in the process of muscle contraction, where acetylcholine released by the neuron triggers the muscle to contract. The correct option is C.

Step-by-step explanation:

The contact between the end point of the axon of one motor neuron and the sarcolemma of the muscle is called the motor endplate. Motor neurons connect to muscle fibers at the neuromuscular junction, a specialized synaptic structure.

Here, axon terminals release acetylcholine (ACh), which binds to receptors on the sarcolemma, opening ligand-gated ion channels that depolarize the sarcolemma and initiate muscle contraction.

This whole process is crucial for the excitation-contraction coupling that leads to muscle contraction. The strength of the muscle contraction can vary depending on the frequency of motor neuron impulses, affecting how many fibers contract and with what amount of force. The correct option is C.