pressure receptors

• Receptor


  Cells which detect stimuli
• Stimulus


  Detectable change in the environment
• Stimulus detection and response

  1. Stimulus detected by receptor

  2. Receptor triggers response
• Nervous system


  • Central nervous system (brain and spinal cord)
  • Peripheral nervous system (receptors, sensory neurons, motor neurons)
• Receptor


  Can only detect and respond to specific stimuli
• Key receptors in AQA specification

  • Pacinian corpuscle
  • Rods
  • Cones
• Action potential


  Generated potential that initiates a response
• Stimulus strength


  Determines if action potential is generated
• Pacinian corpuscle


  Receptor for pressure stimulus
• Pacinian corpuscle


  • Sensory neuron wrapped in layers of connective tissue with viscous gel
  • Contains stretch-mediated sodium ion channels
• Pacinian corpuscle response to pressure

  1. Pressure deforms layers and stretches sensory neuron membrane

  2. Stretch opens sodium ion channels

  3. Sodium ions flow in

  4. Action potential generated