Today we are going to discuss about Central nervous system. Here you will learn about the definition, structure, parts, and function of Central nervous system.

As you know that nervous system is an important system in human body and it is also important topic in biology it plays important role in our body to maintain body functions.

Central nervous system

The human nervous system

All of the processes that happen in the body must be coordinated. This means all organ systems must be made to Work together, doing their jobs at the right time. Coordination is the job of the nervous system. The spinal cord and brain together performing are called the Central nervous system and sometimes CNS.
Millions of nerves branch off from the central nervous system to all parts of the body. The spinal Cord contains many nerves that carry messages between the brain and the body in a network. The neuron is known as basic working unit of the nervous system which is defined below with its types.

Brain

The human brain weighs about 1.5 kg. It contains about 100 billion neurones or nerve cells. Each of these is connected with a thousand or more other nerve cells, making an extremely complex network of cells and nerve fibres. The brain receives and sends messages to organs and muscles along a
network of nerve fibres. The messages are sent as tiny electrical impulses which can whizz along at speeds of up to 100 metres per second. The brain has nerves which directly connect it to the organs of the head, but most nerves are connected to the brain by way of the spinal cord.

Nerve cells (neurons)

Nerve cell or neuron

Nerve cells are long and thin, some are over a metre long. A neuron consists of a cell body containing a nucleus and special extensions called Axons and dendrites. Dendrites bring information to cell body while axons take information away from cell body. Messages travel along nerve cells as tiny electrical Signals or impulses. Impulses can only travel in one direction so, there have to be two Kinds of nerve cell.

Important thing is that the sciatic nerve is known as the longest nerve in our (human) body, It runs from the lower back all the way to the foot.

Sensory nerve cells (or sensory neurons)

They carry impulses from sense receptors around the body to the central nervous system.

Motor nerve cells (or Motor neurons)

They carry impulses from the central nervous system to muscles and glands.

Nerves

Nerve

A nerve is a bundle of nerve fibres. These nerve fibres can comprise sensory nerve cells, motor nerve cells, or a mixture of both. The fibres are wrapped in fatty insulation. A nerve is a bit like an electric cable: the nerves fibres are the wires and thea fatty insulation is the plastic around the cable.

Central nervous system:Nerve cells(neurons), and Nerves | DigitalWorldEdu