the central nervous system

• the central nervous system controls behaviour and the regulation of the body’s physiological processes.
• the central nervous system has two parts:

  • the spinal cord - a bundle of nerve fibres enclosed within the spinal column and which connects nearly all parts of the body with the brain
  • the brain - the part of the central nervous system that is responsible for coordinating sensation, intellectual and nervous activity
• the brain has 4 main parts:

  • the cerebrum
  • the cerebellum
  • the diencephalon
  • the brain stem
• the cerebrum is the largest part of the brain and is further divided into four different lobes. it is split down the middle and into two halves called cerebral hemispheres. each hemisphere is specialised for particular behaviours, and the two halves communicate through the corpus callosum.
• the cerebellum sits beneath the back of the cerebrum. it is involved in controlling a persons motor skills and balance, coordinating the muscles to allow precise movements. abnormalities can result in problems like epilepsy.
• the diencephalon consists of:

  • the 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.
  • the hypothalamus - has a number of important functions, including the regulation of body temperature, hunger and thirst. it also acts as the link between the endocrine system and the nervous system, controlling the release of hormones from the pituitary gland.
• the brain stem is 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.
• the cerebrum has four lobes:

  • frontal - involved with functions such as speech, thought and learning
  • parietal - processes sensory information such as touch, temperature and pain
  • occipital - processes visual information
  • temporal - involved with hearing and memory