Mechanoreceptors – detects a mechanical stimulus (i.e. pressure)

Type of Neurone Sensory
Location Dermis (Skin)
Size ~1mm
Function Detect Mechanical Stimuli

Anatomy

  • Found in the deeper layers (Dermis)  of the skin primarily fingers, external genitals and soles of feet. Also in tendons, ligaments and joints. 
  • Approx 1mm diameter
  • Contains a single myelinated sensory nerve ending (the end of a neurone)
  • Sensory nerve ending is wrapped in lamellae (layers of connective tissue with viscous gel between)
  • Blood capillary which surrounds the inner wall of the capsule provides relevant nutrients for optimal cellular function (i.e. glucose, Na, water etc.) 

Function

  • Stimulation occurs (e.g. tap on the arm)
  • Lamellae deforms and press on the sensory nerve ending
  • Sensory neurone cell membrane stretches which deforms the stretch-mediated sodium ion channels
  • Channel opens and Na+ diffuses into the sensory neurone cell creating a generator potential
  • If generator potential exceeds threshold level it will trigger depolarisation of the sensory neurone which will cause an action potential to travel along the axon
  • Action potential is taken to CNS where a response will be produced (e.g. feeling the tap on the arm)