rod cells are located at the outer edges of the retina in the retina.
rod cells are located at the outer edges of the retina in the retina.
where are rod cells located in the retina?
outer edges of the retina
rod cells are photoreceptor cells in the retina of the eye that can function in less intense light than the other type of visual photoreceptor, cone cells. rods are usually found concentrated at the outer edges of the retina and are used in peripheral vision. on average, there are approximately 92 million rod cells in the human retina. rod cells are more sensitive than cone cells and are almost entirely responsible for night vision. however, rods have little role in color vision, which is the main reason why colors are much less apparent in dim light, and not at all at night.
rod cell
the importance and versatility of depolarization within cells can be seen in the relationship between rod cells in the eye and their associated neurons. when rod cells are in the dark, they are depolarized. in the rod cells, this depolarization is maintained by ion channels that remain open due to the higher voltage of the rod cell in the depolarized state. the ion channels allow calcium and sodium to pass freely into the cell, maintaining the depolarized state. rod cells in the depolarized state constantly release neurotransmitters which in turn stimulate the nerves associated with rod cells. this cycle is broken when rod cells are exposed to light; the absorption of light by the rod cell causes the channels that had facilitated the entry of sodium and calcium into the rod cell to close. when these channels close, the rod cell produces less neurotransmitter, which is perceived by the brain as light. in the case of rod cells and neurons, depolarization actually prevents a signal from reaching the brain as opposed to stimulating the transmission of the signal.
depolarization