The Nervo

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What does the Nervous System do?

The Nervous System is the body’s control and communication system. Nerves carry instant messages from the brain to every part of the body and back again, so it can process the information and make any adjustments.

What body parts are in the Nervous System?

The brain and the Spinal Cord are the main parts of the Central nervous system, which is further divided into the Peripheral and Autonomic nervous systems.

The Brain

The BRAIN is a delicate organ made from more than 100 billion nerves cells called neurons and is protected by the skull. Each Neuron is connected to as many as 25,000 other neurons so the brain has many trillions of different pathways for nerve signals.

The Spinal Cord

The spinal cord is a bundle of nerves that runs down a tunnel in the middle of the back bone, and is the route for all nerve signals travelling between the brain and the body.

The outside of the spinal cord is made up of long tails (axons) of nerve cells and is called white matter. The inside is made up of the main nerve bodies and is called grey matter.

This picture shows the position of the spinal cord protected by the vertebra bones with the spinal nerves branching off.

The spinal cord is about 43cm long and 1cm thick, and it stops growing when you are about 5 years old.

Nerve CellsNerve cells link together to form the nervous system, like beads on a string.

Electrical signals from one nerve cell pass along its tail (axon) to other nerve cells within the system.

These green lines are all the major nerves in the body, there are many more smaller ones.

The longest and largest nerves are the sciatic nerves, which are as wide as your thumb! They start at your lower back and run right down your legs to your little toes.

The Cranial nerves

The green lines are cranial nerves. The pink one is the spinal cord.

The central nervous system (CNS) maintains all bodily functions that keep us alive and can adjust according to the surroundings. E.g. body temperature. It is also responsible for thoughts, emotions and memories.

C.N.S.

The Peripheral nervous system (PNS) is made up of the nerves that branch out in pairs from the CNS to the rest of the body. In the PNS there are 12 cranial nerves of the head and 31 pairs of spinal nerves. They are made of long bundles of nerve fibre, like wires in a telephone cable.

P.N.S.

The autonomic system (ANS). The ANS controls internal body processes that we don’t think about like breathing and digestion.The ANS splits into two further systems, the Sympathetic and Parasympathetic. The Sympathetic system speeds up body processes and the Parasympathetic system slows them down again.

A.N.S.

By Ruby