Create a concept map of what happens in a photo receptor in the dark

Stimulation of the Photoreceptors

a. The visual pigment of rods is rhodopsin and is formed and broken down within the rods.
b. The breakdown and regeneration of the visual pigments of the cones is essentially the same as for rhodopsin.

Exposure of the photoreceptors to light causes pigment breakdown, which
hyperpolarizes the receptors inhibiting the release of neurotransmitter conveying
the information.

Visual Pathway to the Brain

a. The retinal ganglion cells merge in the back of the eyeball to become the optic nerve, which crosses at the optic chiasma to become the optic tracts.
b. The optic tracts send their axons to neurons within the lateral geniculate body of the thalamus.
c. Axons from the thalamus project through the internal capsule to form the optic radiation of fibers in the cerebral white matter. These fibers project to the primary visual cortex in the occipital lobes.

Visual processing occurs when the action of light on photoreceptors hyperpolarizes them, which causes the bipolar neurons from both the rods and cones to ultimately send signals to their ganglion cells.