Pacinian Corpuscle

• Where is the pacinian corpuscle found?

  Deep in the skin of fingers, soles of feet, and external genitalia.
• What stimuli does the pacinian corpuscle specifically respond to?

  Changes in mechanical pressure.
• How does the pacinian corpuscle create a generator potential?

  It converts the mechanical energy of a stimulus into a nervous impulse.
• How is the pacinian corpuscle structured?

  It has a single sensory neuron in the centre wrapped with layers of tissue, each separated by gel.
• What special channel protein does the sensory neurone ending have?

  A stretch-mediated sodium channel.
• Why is the channel protein on the sensory neuron called a strech-mediated sodium channel.

  As their permeability to sodium changes when they are stretched and deformed.
• Why is resting potential maintained in the pacinian corpuscle?

  The stretch-mediated sodium channels are too narrow for diffusion of sodium ions across the sensory neuron membrane, at resting state.
• What happens when pressure is applied to the pacinian corpuscle?

  It is deformed and the membrane becomes stretched which widens the sodium channels, allowing Na+ ions to diffuse across into the neuron.
• What does the influx of sodium ions into the neuron do?

  Depolarises it, creating a generator potential.
• What does the generator potential in turn create?

  An action potential.