the nervous system

• Spinal cord


  The main function is to relay information between the brain and the rest of the body
• Functions of the spinal cord

  1. Allows the brain to monitor and regulate bodily processes, such as digestion and breathing

  2. Coordinates voluntary movements
• Spinal nerves

  • Connected to different parts of the body
  • Connect with specific muscles and glands
  • Branch off from the thoracic region and carry messages to and from the chest and parts of the abdomen
• Reflexes


  1. Spinal cord contains circuits of nerve cells that enable us to perform some simple reflexes without the direct involvement of the brain

  2. For example, pulling your hand away from something that is hot
• Spinal cord is damaged


  Areas supplied by spinal nerves below the damaged site will be cut off from the brain and will stop functioning
• The brain

  Can be divided into four main areas: the cerebrum, cerebellum, diencephalon and brain stem
• Cerebrum


  • Largest part of the brain
  • Further divided into four different lobes, each with a different primary function
  • Split down the middle into two halves called cerebral hemispheres
  • Each hemisphere is specialised for particular behaviours
  • The two halves communicate with each other through the corpus callosum
• Frontal lobe

  Involved in thought and the production of speech
• Occipital lobe

  Involved in the processing of visual images
• Cerebellum


  • Sits beneath the back of the cerebrum
  • Involved in controlling a person's motor skills and balance
  • Coordinates the muscles to allow precise movements
  • Abnormalities can result in speech and motor problems and epilepsy
• Diencephalon


  • Lies beneath the cerebrum and on top of the brain stem
  • Contains the thalamus and the hypothalamus
• Thalamus


  Acts as a relay station for nerve impulses coming from the senses, routing them to the appropriate part of the brain where they can be processed
• Hypothalamus


  • Regulates body temperature, hunger and thirst
  • Acts as the link between the endocrine system and the nervous system, controlling the release of hormones from the pituitary gland
• Brain stem


  • Responsible for regulating the automatic functions that are essential for life, including breathing, heartbeat and swallowing
  • Motor and sensory neurons travel through the brain stem, allowing impulses to pass between the brain and the spinal cord