Answer:
The basic building block of the nervous system is a nerve cell, or neurone. Neurones are shaped differently depending on where they are in the body and what role they play. All neurones have finger-like projections called dendrites and a long fibre called an axon. In many cases, the axon is coated by a specialised membrane called a myelin sheath. The axon feathers out and has a number of bumps on it. Each bump sits near to a dendrite from another neurone. The space between the bump and the dendrite is called a synapse. Messages jump the synapse from one neurone to the next, using special chemicals called neurotransmitters.
Unlike other cells in the body, neurones aren’t easily replaced if they die or are damaged by infection or injury
Explanation: I hope this helped :)