Senses

• The five traditional senses

  • Touch
  • Smell
  • Taste
  • Sight
  • Hearing
• Glue ear is a hearing disorder caused by too much sticky fluid in the middle ear, corrected by decongestants or grommets
• The skin

  organ of touch
• Taste

  Receptors for taste are in taste buds
• Smell

  Olfactory neutrons in the nose detect smell
• Sciera 


  A tough white outer coat that holds eye in shape
• Choroid


  Dark coloured layer that contains blood vessels, prevents internal infection of light
• Retina 


  Contains receptors called rods and cones
• Fovea


  part of retina where most images are focused
• Optic nerve


  Carries impulses from eye to brain
• Blind spot 


  No rods or cones at the blind spot
• Cornea 


  Part that allows light in
• Lens 


  focuses light on retina
• Cillary muscle 


  Changes shape of lens
• Suspensory ligaments 


  Connect ciliary muscle to lens
• Rods 


  Work in dim light

  detect black and white
• Cones 


  Detect colours

  work in bright light
• Iris


  coloured part of the eye
• Pupil 


  Black circle in centre, allows light into eye
• Aqueous and vitreous humours 


  Liquids that suport the eye
• Vestibular apparatus

  Detects balance in the inner ear
• Pinna

  Made of cartilage, collects vibrations
• Auditory canal 


  Carries vibrations to eardrum
• Eardrum 


  Tightly stretched membrane that Vibrates when stimulated by vibrations in auditory canal
• Ossicles 


  3 bones, hammer, anvil and stirrup. They increase vibrations in auditory canal
• Eustachian tube 


  Connects middle ear to pharynx. Equalises pressure on either side of eardrum
• Cochlea 


  Responsible for hearing. Converts vibrations into electrical impulses that are sent to the brain along auditory nerve
• Conjunctiva

  Membrane around the eye
• Sclera

  Tough white coat that holds eye in place