The brain and spinal cord

The brain and spinal cord, or central nervous system, control how we think, feel, learn, move and other body functions.

Layers of tissue called the meninges surround and protect the brain. A fluid called cerebrospinal fluid (CSF) circulates between some of the layers to help cushion the brain.

The brain is made up of billions of nerve cells that communicate with each other through a network of nerves. Messages between the brain and parts of the body travel through nerves in the spinal cord.

The main parts of the brain are:

  • The cerebrum – it is the largest area, made of two halves. The right half controls the left side of the body and the left the right. Each half divides into four lobes that control different functions, such as, thinking, memory, behaviour, personality, learning, hearing, sight, language and touch.
  • The cerebellum – this is at the back of the brain and controls balance and coordination.
  • The brain stem – controls vital functions such as breathing and heart rate.
  • The pituitary gland – at the base of the brain, it controls hormone production in the body.

The central nervous system

The brain and the spinal cord make up the central nervous system (CNS). The brain controls how we think, feel, learn and move. It also controls lots of other things in the body without us having to think about it, such as our breathing and heart rate. The brain is protected by the bones of the skull.

The spinal cord is made up of nerves (nervous system) that run down the middle of your back (spine). Messages between the brain and other parts of the body travel through the spinal cord. The spinal cord starts at the base of the brain and goes down to the small of your back. The bones of the backbone protect the spinal cord.

The brain and spinal cord are covered and protected by three layers of tissue (membranes) called the meninges. The area between two of these layers is called the subarachnoid space. It contains a fluid called cerebrospinal fluid (CSF) which acts as a protective cushion for the brain. It also circulates nutrients to the brain and removes waste products.

Nerve cells (neurons)

The brain is made up of billions of nerve cells, called neurons. They communicate with each other, and other parts of the body by sending messages (nerve impulses) through a network of nerves.

Nerve cells are held in place and supported by glial cells. There are different types of glial cells, including astrocytes, oligodendrocytes and ependymal cells. Unlike other body cells, nerve cells can’t replace themselves. They gradually decrease in number as we get older.

Main areas of the brain

The main parts of the brain are the cerebrum, cerebellum, brain stem and pituitary gland.

Cerebrum

This is the largest part of the brain and is made up of two halves (hemispheres). It controls thinking, memory and personality and makes us who we are. The right half of the cerebrum controls the left side of the body, and the left half controls the right side of the body.

A cross-section of the brain
A cross-section of the brain

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Each half of the cerebrum is divided into four areas, or lobes:

  • The frontal lobe is responsible for thinking, memory, planning, problem solving and behaviour. Part of the frontal lobe, near the top of the brain, controls movement in the arms and legs.
  • The parietal lobe helps us form words. It’s also responsible for touch and other sensations, and awareness of our body position.
  • The temporal lobe is responsible for our emotions, how we understand things and processing what we hear and smell. It also helps us with organising information and learning.
  • The occipital lobe processes information about what we see, for example colour, shape and distance.

Lobes and functions of the brain
Lobes and functions of the brain

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Cerebellum

This is below the cerebrum, at the back of the brain. It controls balance and coordination.

Brain stem

The brain stem is at the bottom of the brain and connects to the spinal cord. It controls essential body functions that keep us alive, such as breathing, heart rate, blood pressure, body temperature. It also controls eye movements and swallowing.

Pituitary gland

The pituitary gland is just below the base of the brain. It makes different hormones that control other hormone producing glands in the body.


Back to Understanding brain tumours

Primary brain tumours

Primary brain tumours may be benign or malignant. There are several types of brain tumours.

How brain tumours are treated

Treatments for brain tumours include surgery, radiotherapy, chemotherapy and also drugs to treat symptoms. You may have a combination of treatments.

Secondary brain tumours

Secondary brain tumours happen when cancer cells spread to the brain from a cancer in another part of the body.

Types of brain tumour

and how they affect different parts of the brain

What is a brain tumour?

Brain tumours can be benign (not cancer) or malignant (cancer). Cancer is a disease caused by the abnormal division of cells. This uncontrolled division of cells then forms a tumour.