Question

Cell body of neuron is called
A) Nissl body
B) Neurolemma
C) Oligodendrocyte
D) Perikaryon

Answer 1

Hint: Neurons are structural and functional units of Nervous System. These contain the nucleus and the cytoplasm around it. Nucleus is known as ‘Karyon’.

Complete Answer:
Nervous system consists of Neurons and Neuroglial cells. Neurons are less than 50% while Neuroglial cells are more than 50%. Neurons are of various types depending on the number of processes. These are Unipolar, Bipolar, Multipolar and Pseudounipolar.
Maximum number of neurons are Multipolar.

Structure of Multipolar neurons is as follows:

It consists of many processes around the cell body:
1) There are short processes that carry impulses towards the cell body. These are dendrites. These further contain branches called dendrons.
2) The main process arising from the cell body that carries impulses away from the cell body is the Axon.
3) Thus the multipolar neurons contain one Axon and many Dendrites.
4) The cell body contains nucleus and Nissl granules. Nissl granules are Ribosomes that take part in protein synthesis.
5) The end of the Axon terminates into the Axon terminal that forms Synaptic knobs that contain vesicles filled with neurotransmitters.
6) The cell body is around the nucleus. Nucleus is karyon so the cell body is around and hence it is Perikaryon or Cyton.
7) The Multipolar neuron can be Myelinated or Unmyelinated. This is due to the presence or absence of Myelin sheath.
8) Neuroglial cells are supporting cells and not for conduction of impulses. These cells are Schwann cells, Oligodendrocytes, Microglial cells, Ependyma, etc.

Hence the correct answer is option ‘D’.

Note: The cell is a structural and functional unit of the life. Thus depending on different functions, the cells differ in structures too.
Example:
1) The neurons are for conduction and hence possess processes
2) Muscle cells undergo contraction and relaxation and hence are elongated
3) RBC’s circulate through the blood and hence are biconcave in shape