Question

What is the somatic nervous system?

Answer 1

Hint: This nervous system is actually a part of the peripheral nervous system. The peripheral nervous system is defined as that part of the nervous system that consists of the afferent (sensory) and efferent (motor) nerves, which connect the different parts of the body with the CNS. This part of the nervous system constitutes non-myelinated nerve fibers.

Complete answer:
On the basis of origin, the peripheral nervous system consists of two parts:
Cranio-spinal nerves: They again comprise the spinal nerves (12 pairs) and cranial nerves (12 pairs).

Autonomic nerves: They consist of the parasympathetic and sympathetic nerves.
Again, on the basis of nerve type, i.e., either motor and sensory, the peripheral nerves are again classified into two main types:
Motor nerves

Sensory nerves: originate from the posterior horn of grey matter in the spinal cord.
The motor neurons are broadly classified into two main types:
1. Somatic nervous system: This system consists of the motor neurons that are supplied to those organs that can be controlled by our own will like the skeletal muscles.
They originate from the anterior horn of the grey matter.
2. Autonomic nervous system: This system consists of the motor neurons that regulate the involuntary parts of the body.
These nerves originate from the lateral horn of the grey matter in the spinal cord.
They again are subdivided into three main types:
a. Sympathetic
b. Parasympathetic
c. Enteric

Thus, the somatic nervous system only consists of motor nerves and helps us to control the voluntary functions of the body. From the point of origin, they are cranio-spinal nerves in nature.

Note:
The nervous system consists of two parts- the central nervous system and the peripheral nervous system. The somatic motor nervous system falls under the peripheral nervous system. Some cranial nerves may have their cell bodies in the brain while their axons move down into the spinal cord and then come out from their respective regions. So, it may seem like the nerves are arising from the spinal cord region, but actually, they are arising from the cranial part.