-Aqsa, Subject Matter Expert at Edumarz.
Solution: A neuron is the basic unit of the neural system. The number of neurons varies in animal species. The majority of the neurons occur in the brain. Neurons are structurally and functionally the most complicated cells. They may be round, oval, flask, or star-shaped. A neuron consists of the following parts:
Cell body – The main cell body or cyton contains a large nucleus surrounded by granular cytoplasm having several mitochondria, ribosomes, lysosomes, Golgi bodies, endoplasmic reticulum, and granules. It also contains Nissl granules consisting of nucleoprotein combined with iron. Centrosomes are absent in neurons, due to which they cannot divide.
Dendrites – They may be one too many and arise from one side of the cell body. They help in receiving an impulse from the receptor and bringing it to the cyton.
Axon – It is a single, long, and tubular structure. It helps in conducting impulses away from the axon. The cytoplasm inside the axon is called axoplasm covered with a plasma membrane called axolemma. The axoplasm contains mitochondria and neutrophils. Axons can be more than 1 meter in length, making neurons the largest cell in the body. The terminal end of the exon is termed a synaptic knob.