sensory receptors

• sensory receptor

  • detect change in the surroundings (stimulus)
  • each receptor is adapted to detecting a different type of energy
  • They act as 'energy transducers' - they convert a stimuls into a nerve impulse
• mechanoreceptor:

  stimulus - movement and pressure

  example of receptor - pacinian corpuscle

  example of sense organ - skin
• chemoreceptor:

  stimulus - chemical

  example of receptor - olfactory receptor

  example of sense organ - nose
• thermoreceptor:

  stimulus - heat

  example of receptor - end bulbs of krause

  example of sense organ - tongue
• photoreceptor:

  stimulus - light

  example of receptor - cone cell

  example of sense organ - eye
• pacinian corpuscle

  • sensory receptor
  • detects pressure
  • found in the fingertips and joints
  • produce a generator potential
  • turns pressure into an a nervous impulse
  • acts as a transducer
• pacinian corpuscle

  • membrane around pacinian corpuscle has stretch mediated sodium channels
  • these channels open when stretched and deformed
  • allowing sodium ions to diffuse into the neurone causing depolarisation resulting in the generator potential