Question

Draw a labelled diagram of the neuron and describe the structure of neuron in detail.

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. The cell body contains cytoplasm and certain granular bodies called Nissles 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 the branched distal end.
It terminates in bulb-like structures called synaptic knob. It is filled with chemicals called neurotransmitters.
Parts of Axon:
a. Axoplasm: It is the cytoplasm of the 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.