Question

Answer the following question.

Describe the structure of multipolar neuron.

Answer 1

A neuron is the structural and functional unit of the nervous tissue. A neuron is made up of cyton or cell body and cytoplasmic extensions or processes. 

It is star-shaped and gives out more than two processes. 
There is only one axon and the remaining are dendrons. Axon initiates from a funnel-shaped area called axon-hillock. 

1. Cyton: The cyton or cell body contains granular cytoplasm called neuroplasm and a centrally placed nucleus. The neuroplasm contains mitochondria, Golgi apparatus, RER, and Nissl’s granules.
2. Cytoplasmic extensions or processes:

• Dendron: They are short, unbranched processes. The fine branches of a dendron are called dendrites. Dendrites carry an impulse towards the cyton.
• Axon: It is a single, elongated and cylindrical process. The axon is bound by the axolemma. The protoplasm or axoplasm contains large number of mitochondria and neurofibrils. The axon is enclosed in a fatty sheath called the myelin sheath and the outer covering of the myelin sheath is the neurilemma. Both the myelin sheath and the neurilemma are parts of the Schwann cell. The myelin sheath is absent at intervals along the axon at the Node of Ranvier. The fine branching structure at the end of the axon (terminal arborization) is called a telodendron.