Our brain is enclosed in our skull. The nervous system originates here and spreads to all parts of the body. The organs which help us to think are located in the brain. It is through them that we experience the feelings of joy and sorrow as well as the sensations of light, darkness, heat and coldness. These organs exercise control on the other organs of the body. The nervous system can be compared to the monarch placed in the capital of the body. If we operate upon the skull, the brain can be seen inside it. The shape of the brain is like the kernel of a Walnut.

The brain controls the operations of the body through the neurons (nerve fibers). These fibers resemble a strong string, which is not easily broken by pulling and when cut appears solid from inside.

Functions of the Sensory Nerves

Sensory nerves operate like electric wires. Just as electric Wires carry messages from one place to another these live nerves also carry messages from one place of the body to another. The brain rules the body like a king, and the nerves are its messengers or agents. The orders of the brain reach other organs through these sensory nerves.

The brain can be divided into two main parts: large and small. The large part has several smaller parts which play different roles in different parts of the body. If one purl is concerned with the movements of the body, the others give the feeling of pain, heat, coldness etc. Some parts have their relationship with the power of thinking and reasoning, some with seeing, smelling and tasting. Though separate, these parts are connected with each other through nerves.

There are two centers of the ‘larger’ brain on right and left. The right centre controls the left part of the body while the left controls the right part. These centers are responsible for their territories like the officers in charge of departments or like the district officers of a district in a State. If the need arises, they work in cooperation with one another.

Whenever there is any movement in our body, some muscles contract and others expand. Both these things are necessary for each and every movement of the body. When we bend our elbow, the front muscles become loose. If the contracting muscles do not contract and the expanding muscles do not expand, it would not be possible for us to bend our elbow. The same is true of the movements like walking, sitting, standing and chewing.

Whereas some muscles are ordered by the brain through the sensory nerves to contract, the others are ordered to stop contraction. When both these orders are conveyed and obeyed properly, only then can we move our limbs. The ‘small’ brain is responsible for the proper conduct of all these movements.