Receptors and the Pacinian Corpuscle

Receptors

Respond to stimuli to produce generator potentials in sensory neurones

depolarisation

when a cells membrane potential becomes less negative

generator potentials

produced by an influx of Na+ ions into a neurone

how depolarisation of neurone membranes occurs

sufficient supply of sodium ions

depolarisation of neurones

creates an electrical impulse

Pacinian corpuscle

receptors deep in the skin and joints which respond to the physical stimuli of change in pressure

Stimulus which causes the Pacinian corpuscle to change shape

pressure

what the change in shape of the Pacinian corpuscle causes

stretching of lamellae membranes of neurones

what the stretching of lamellae membranes of neurones causes

widening of the stretch mediated channels allowing a proportionate amount of Na+ ions to the amount of pressure applied into the sensory neurone

what a supply of sodium ions into the neurone creates

generator potential which depending on the supply of Na+ ions may produce a nerve impulse

Process of producing a generator potential in the Pacinian Corpuscle

Pressure acts as as a stimulus and deforms the lamella membrane of the PC

this causes the cell surface membrane of the PCs sensory neurone to be deformed

stretch mediated sodium ion channels then open allowing an influx of sodium ions to pass into the neurone

this causes the neurone membrane to become depolarised creating a generator potential

if enough pressure has been applied the threshold potential will be met and an action potential will be produced

substance in between lamellae membranes in a Pacinian corpuscle

viscous gel

Habituation

skin gets used to a stimulus and we cease to be aware of it

Resolution of touch receptors

how close together in distance two stimuli have to be to be detected as one stimulus