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Cells and control III - Coggle Diagram

- - - - Largest part of brain
      - Divided into two halves called cerebral hemishperes
      - Right hemishpere controls muscles on the left side of our body and vice versa for the left hemisphere
      - Cerebrum is responsible for movement, intelligence, memory, langauge and vision
    - - Found at the back of the brain
      - Responsible for muscle coordination nad balance (precise movement)
    - - At the base of the brain
      - Controls unconscious activities like breathing and heart rate
  - - - Uses X-rays to produce an image of the brain
      - Shows the structures of the brain, but not the functions
      - Creates a 3D image
      - Exposes patient to higher does of radiaiton than normal
    - - Before the scan the person is injected with a radioactive chemical called a tracer, it moves around the body and collects in different areas, including the brain
      - More active cells take up more tracer than less active cells
      - Images can show which parts of the brain are active
      - PET scans are very detailed, are used to investigate structure and function of the brain
      - Can show if areas in the brain are unusually inactive or active
- - - - 1) Ciliary muscles contract, suspensory ligaments relax
      - 2) lense becomes thicker and more rounded
      - 3) increases the amount by which light is refracted
    - - 1) Ciliary muscles relax, suspensory ligaments tighten
      - 2) Lense becomes narrower, less rounded
      - 3) Light is refracted by a smaller amount
  - - - People unable to focus on near objects
      - Occurs when lens is wrong shape and doesn't refract the light enough or the eyeball is too short
      - Image of near objects are brought into focus behind the retina
      - Glasses with a convex lens (curves outwards) can correct long sigtedness
    - - People unable to focus on far objects
      - Occurs when lens is the wrong shape and refracts light too much or the eyeball is too long
      - Image of distant objects are brough into focus infront of the retina
      - Glasses with a concave lense (curves inwards) can correct short sightedness
  - - - People who can't tell the difference between certain colours
      - Occurs when the cons in the retina don't work properly or one is missing entirely
      - No cure as cone cells can't be replaced
    - - Cloudy patch on the lense which stops light entering the eye normally
      - Causes blurred vision and less vivid colours aswell as trouble seeing in bright light
      - Can be surgically treated by replacing the faulty lense with an artificial one