Structure and function of the brain

• Brain is responsible for processing all the information collected by receptor cells about changes in the internal and external environment.

  Also receives and processes information from hormonal system.
• Cerebrum

  = Controls voluntary actions like learning, memory, personality and conscious thought.

  • Receives sensory information, interprets it from previous experience, then sends impulses along motor neurones to effectors.
  • Highly convoluted- increases it's surface area and it's capacity for complex activity.
• • Outer layer of cerebrum= cerebral cortex
  • Reasoning and decision making occur in frontal and prefrontal lobe of cerebral cortex.
  • Each sensory area within cerebral hemispheres receives information from receptor cells in sense organs. Size of sensory area is relative to the number of receptor cells present. Information then passed to association areas in brain to be analysed and acted upon.
  • Size of impulse in proportion to number of motor endings in it.
• Cerebellum 


  = Controls unconscious functions like posture, balance and non-voluntary movement

  • Concerned with control of muscular movement, body posture and balance- doesn't initiate movement but coordinates it.
  • Receives information from organs of balance in ears and information about the tone of muscles and tendons.
  • It then relays this information to areas of cerebral cortex involved in motor control.
• Medulla oblongata

  = Used in automatic control eg: heart rate, breathing rate.

  • Contains important regulatory centres of ANS.
  • These control reflex activities.
  • Also controls swallowing, peristalsis, coughing.
• Hypothalamus 


  = Regulatory centre for temperature and water balance.

  • Control complex patterns of behaviour like feeding, sleeping, aggression.
  • Monitoring composition of blood plasma like concentration of water and blood glucose, has a rich blood supply
  • Producing hormones
  • Main controlling region for ANS
• Pituitary gland

  = Stores and releases hormones that regulate many body functions.

  • Anterior pituitary= produces 6 hormones including FSH.
  • Posterior pituitary= stores and releases hormones produced by hypothalamus such as ADH.