Neuronal communication
Sensory receptors
○ Convert stimulus into a nerve impulse = TRANSDUCER
○ Specific to a single type of stimulus
TYPES
Mechano Pressure and movement
Chemo Chemicals
Thermo Heat
Photo Light
PACINIAN CORPUSCLE
○ Deep within skin
○ Detect mechanical pressure
○ Within joints to indicate which joint is changing direction
STRUCTURE
End of the sensory neurone is within the centre, surrounded by layers of connective
tissue
In the membrane there are Na+ channels
At the neuron ending, stretch-mediated Na+ channels change shape when stretched
, 2
Converting MECHANICAL PRESSURE into a NERVOUS IMPULSE
1) At resting potential, stretch-mediated Na+ channels are too narrow
2) Stimulated by pressure: corpuscle changes shape and the surrounding
membrane stretches
3) Na+ channels widen
4) Na+ diffuse into the cell = depolarised
5) Generator potential = action potential
Sensory receptors
○ Convert stimulus into a nerve impulse = TRANSDUCER
○ Specific to a single type of stimulus
TYPES
Mechano Pressure and movement
Chemo Chemicals
Thermo Heat
Photo Light
PACINIAN CORPUSCLE
○ Deep within skin
○ Detect mechanical pressure
○ Within joints to indicate which joint is changing direction
STRUCTURE
End of the sensory neurone is within the centre, surrounded by layers of connective
tissue
In the membrane there are Na+ channels
At the neuron ending, stretch-mediated Na+ channels change shape when stretched
, 2
Converting MECHANICAL PRESSURE into a NERVOUS IMPULSE
1) At resting potential, stretch-mediated Na+ channels are too narrow
2) Stimulated by pressure: corpuscle changes shape and the surrounding
membrane stretches
3) Na+ channels widen
4) Na+ diffuse into the cell = depolarised
5) Generator potential = action potential
