In our eyes, we have cells that make us able to see the world around us called photoreceptors. These photoreceptors are rods and cones. Rods and cones are both long cells but have slightly different structures. Rods and cones are long cells with three main sections: the synaptic terminal, the inner segment and the outer segment. The synaptic terminal has the nerve ending that send signals to the brain to communicate what it is seeing, so for rods it would be light or dark changes and general shapes, and for cones it would be sending color signals and making our vision clear. The inner segment contains the nucleus of the cells and the mitochondria. The outer segment, to put in a simple term, looks likes the teeth on a comb but made of plasma membranes. On rods, this section is longer and has disks within it making it larger and more rectangular. The cones look more triangular and don't contain those disks.
We have about 120 million rods in our eyes, mainly in our peripheral vision, and only 6-7 millions cones, mainly concentrated in the center of our eyes called the fovea. Even with the abundance of rods and cones we still have a blind spot in our eyes where light can't hit the photoreceptors. Rods and cones are classified as nervous tissue because they send signals to the brain about what they see.
Rod Cell: Cone Cell:
Works Cited:
"Neuroscience For Kids." - Retina. N.p., n.d. Web. 31 Aug. 2015.
Purves, Dale. "Functional Specialization of the Rod and Cone Systems."Functional Specialization of the Rod and Cone Systems. U.S. National Library of Medicine, n.d. Web. 31 Aug. 2015.
Very detailed and insightful. Blindspot information was very interesting.
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