in the leg muscles can be made to perform very special movement under the control of the conscious mind (voluntarily). Hence in a football game, the muscles of the leg operate both by reflexes and voluntarily. Most actions of our body are actually controlled together by voluntary and involuntary pathways.

Think of any action and try to make a sketch of the reflex arc. The voluntary and involuntary actions in our body are controlled by nervous system as a whole.We may study our nervous system on the basis of areas from which nerves originate and then spread out to the whole body as mainly two divisions one is the central nervous system (CNS) and the other is peripheral nervous system (PNS)

Central nervous system includes brain and spinal cord. It coordinates all neural functions

When compare to body weight human brain is the largest of all the animals. The brain is present in the hard bony box like structure called cranium. It is covered by three layers called the meninges. The meninges are continuous and cover the spinal cord as well. The space between the inner layers is filled with fluid called cerebro-spinal fluid. It serves as a shock-absorbing medium and protects the brain against shocks/jerks along with the meninges and cranium. Mainly the nerve cell bodies together with capillaries form a mass called grey matter while the myelinated axons or those covered by fatty sheaths form white matter. The grey matter is usually present on the periphery while white matter is present towards the center. This is mainly due to the fact that there is a small area from where the myelinated axons leave the brain. As we have already studied, the function of the brain as a control center was known nearly 2000 years back by Greek physiologists.

Brain has the following divisions -
1. Forebrain - cerebrum,
diencephalon
2. Midbrain - optic lobes
3. Hindbrain - cerebellum, medulla
oblongata