Nociceptors respond to changes in pressure.

Meissner's corpuscles are thermoreceptors.

Photoreceptors in the human eye are depolarised during darkness and become hyperpolaized in response to the light stimulus.

Receptors do not produce graded potentials.

opsin and retinol

transducin and retinene

guanosine and retinol

opsin and retinal.

only rods are present

more rods than cones are found

high density of cones occur, but has no rods

the optic nerve leaves the eye.

commissural impulses

integrating impulses

sensory impulses

voluntary motor impulses.