Question

A neuron has three main parts: dendrites, cell body, and axon. A neuron may send signals to other neuron or other tissues (effectors). Describe the physiology of how the signal moves from one point to the other and the other organ or tissue responds.

Answer 1

ANSWER :

When a threshold stimulus (-55 mV) or electrical signal via dendrites at the cell body (or cyton) of a neuron, which cause opening of voltage-gated sodium ion channels.

After opening of sodium ions channels, Na+ located outside begin to move inside the cell, that lead to depolarization in the cell membrane, and followed by generating action potential along the length of axon of nerve cell, and when action potential reached at the terminals of axon it cause opening of Ca++ (calcium ions) channels, which stimulates the release of acetylcholine (neurotransmitter) from the synaptic vesicles into the synaptic cleft.

The neurotransmitter passes through the synaptic cleft, and binds to the specific receptor on the postsynaptic neuron, or effector tissue or organ, and lead to cause their further depolarization to transmit electrical impulse in them.