Nervous system is made up of cells better known as neuron. Nervous system consists of central nervous system and peripheral nervous system.

Central Nervous System

This consists of brain and spinal cord. Brain is the organ that receives processes and gives directions to the parts of the body. Spinal cord serves as a pathway. All the impulses are received and passed only through spinal cord.

Peripheral Nervous System

This is a part of the nervous system. This consists of nerves that extend and reside from central nervous system. These nerves are supplied to the limbs and organs. This nervous system is not protected by bone and blood brain barrier. This nervous system is divided in to somatic nervous system and autonomic nervous system.

Somatic Nervous System

These nerves are responsible for the control of voluntary movements of the body. These nerves are also used to receive the external stimuli. Somatic nervous system consists of afferent nerves [to receive impulses from external stimuli] and efferent nerves [to send impulses from the brain].

Autonomous Nervous System

This consists of sympathetic and Para sympathetic nerves. Parasympathetic nerves are responsible for energy saving and digestion. Sympathetic nerves are responsible for energy expenditure and response.