Question

Explain the structure and function of neuron.

Answer 1

The structure of neuron: Nerve cells or neurons are the structural and functional units of the nervous system. It consists of three major parts namely, cell body, dendrites, axon.
Cell Body: It is irregular in shape or polyhedral. It contains cytoplasm and certain granular bodies called Nissl's granules which contain a group of ribosomes for protein synthesis.
Dendrites: Dendrites are short fibres which branch repeatedly and protrude out of the cell body. They transmit electrical impulse towards the cyton.
Axon: They are long fibres arising from the cell body with a branched distal end. It terminates in a synaptic knob. It is filled with neurotransmitters.
Parts of axon:
a. Axoplasm: It is the cytoplasm of an axon.
b. Myelin sheath: It is made up of many layers of Schwann cells.
c. Neurilemma: The outermost layer of Schwann cells.
d. Nodes of Ranvier: These are gaps left by a myelin sheath.

Function: The neurons are responsible for the conduction and transmission of the nerve impulses. The stimulus is received and carried by the sensory neurons, analysed and detected by the CNS. The response is given with the help of the motor neurons.