The nervous system is responsible for the communication between different areas of the body. It’s the communication system and its job is to send and receive messages. It controls all thoughts and movements.
It has two main divisions:
Central and Peripheral.

1. Central nervous system is consisted of Brain and Spinal cord. It’s also known as the control centre of the body.

a) The brain processes all the information from around the body and controls the responses that the body makes. It’s the command centre of the entire body and its made of billions of neurons.
Our brain has 3 main parts: 1. Cerebrum: the largest one. Controls vision, touch and other senses, and also handles the control over our movements. Thinking also takes place in the Cerebrum.
2. Cerebellum: Balance and coordination.
3. Brain stem: the link of the brain to the spinal cord, controlling digestion, breathing and heartbeat.

b) The spinal cord plays a similar function but with reflex reactions.
The spinal cord is a tube of neurons that runs up the spine and attaches to the brain stem. Information from the nerves goes to the spinal cord. Also some messages are processed by the spinal cord, but most of the information is sent to the brain for analysis.

2. Peripheral Nervous system: it has two parts: Somatic and Autonomic.
a) Somatic: Conveys sensory information to the Central Nervous System and motor information back to the muscles, joints.
b) Autonomic: Regulates involuntary activity of smooth muscle that controls the vital organs. It also has two divisions. Sympathetic and Parasympathetic system.
Sympathetic prepares the body to deal with stressful situations, for example raises heart rate, causes production of adrenaline, while parasympathetic reverses the effects of the SNS and acts to maintain resting bodily function.
Brain cells are two types: neurons and glial cells.

1. Neurons are cells that send and receive electro-chemical signals to and from the brain and nervous system. There are about 100 billion neurons in the brain. It consists of a cell body (soma) with branching dendrites (the signal receivers) and a projection called axon which conduct the nerve signal. At the other end of the axon its terminals transmit the electro-chemical signal across a synapse (the gap between the axon terminal and the receiving cell).
a) Axon- take information away from the cell body. Bundles of axons are known as nerves or within the central nervous system, as nerve tracts or pathways. The axon conveys information from the dendrites to other neurons or the gland or muscle. These can be Afferent (takes info into a structure) and Efferent (takes info away from a structure).
b) Dendrites bring information to the cell body.
c) Myelin increases the transmission speed along the axon.
d) The cell body (soma) contains the neuron’s nucleus (with DNA and