Your nervous system controls much of what your body does. It allows you to do things like walk, speak, swallow, breathe and learn, and controls how your body reacts in an emergency.
Your nervous system is made up of:
- your central nervous system, or CNS, which consists of the brain and spinal cord
- your peripheral nervous system, which consists of nerves that connect your CNS to the rest of your body.
Nerves are made up of cells called neurons. Each neuron has a cell body, an axon (legs) and many dendrites (connections to other cells).
Dendrites collect information from other cells and pass it to the cell body, while the axon carries messages away from the cell body to other parts of the body.
What does the nervous system do?
Your brain sends messages through your spinal cord and the peripheral nervous system to:
- control the movement of your arms and legs
- control the automatic functions of your body, such as the operations of your heart, your organs and your glands.
The nervous system is also involved in the senses of sight, hearing, taste, touch and smell. Special nerve cells carry information from your eyes, ears, nose, tongue and skin to your brain.
The brain, which is part of the nervous system, carries your thoughts, feelings and emotions, and controls most of the functions of your body, including movement and what you see, hear, feel, taste, smell and say.
Diseases of the nervous system
There are thousands of conditions that start in or affect the nervous system, including:
- degenerative diseases like Parkinson’s, Alzheimer’s and multiple sclerosis
- spinal cord injuries
- seizure disorders, such as epilepsy
- cancer, such as brain tumours
- infections, such as meningitis
What can go wrong?
There are many different symptoms that could suggest a problem with the nervous system. They include:
- blurry vision
- behavioural changes
- leg or arm numbness
- loss of coordination
- weakness or loss of muscle strength
- slurred speech
- emotional problems
- memory loss.
It is important to seek medical help if you have symptoms like these that don’t go away on their own.
Last reviewed: July 2017