• The CNS is the main control centre of your body: it receives, interprets and sends messages so that your body can work properly. It controls how you think, walk, listen to a song and how fast your heartbeats.

  • The CNS is made up of the brain and the spinal cord. The brain is divided into several different parts or lobes. Each lobe has a specific role. Inside the CNS are neurons or special nerve cells.

  • Neurons are covered in a special layer called myelin, just like insulating rubber on an electrical wire. Myelin helps nerve signals travel faster.

  • The spinal cord is a long column (about 44 cm long in an adult) of nervous tissue that runs from the base of the skull to the mid-lower back. All nerves to the arms and legs are connected to the spinal cord.

  • The spinal cord is enclosed within the vertebral column and is surrounded by a protective membrane called the meninges. Within the meninges, the spinal cord is bathed with a clear fluid called cerebral spinal fluid or CSF.


  • The immune system is the body’s way of fighting against infection.

  • The immune system is made up of multiple types of immune cells (E.g., T cells and B cells), lymph glands, bone marrow and the thymus gland.

  • Immune cells remember what infections the body has seen in the past, and are prepared to get rid of these invading infections if they come back.

  • Unfortunately, immune cells can make a mistake and attack a part of the body, (i.e. the brain), thinking it is an unwanted organism or invader.