In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell.——————Neurotransmitters are endogenous chemicals that enable neurotransmission. It is a type of chemical messenger which transmits signals across a chemical synapse, such as a neuromuscular junction, from one neuron (nerve cell) to another "target" neuron, muscle cell, or gland cell.
<span>Facilitated diffusion
Diffusion
occurs because of the movement of molecules from the region of higher
concentration to the region of lower concentration. This movement of
molecules occurs due to a thermal motion. Diffusion normally occurs
between two compartments having difference in concentration. In case of
fluid it moves from the region of higher concentration to the region of
concentration until a balance is reached. The process of diffusion is
very important for the humans as well. The oxygen that humans breathe in
gets diffused with the blood.<span> </span></span>