Choose the correct statement.

Options

A. Nociceptors respond to change in pressure.
B. Meissner's corpuscles are thermoreceptors.
C. Photoreceptors in the human eye are depolarized during darkness and become hyperpolarized in response to the light stimulus.
D. Receptors do not produce graded potentials

Answer

C

Explanation

Shining light on photoreceptor, either a rod sell or a cone, leads to membrane hyperpolarization rather than depolarization. In the dark the receptor is in a depolarized state, with membrane potential of roughly -40mv. Progressive increases in the intensity of illumination cause the potential across the receptor membrane to become more negative (reaches about -65 mv.)