Editing Rod cell (section)

==Structure==
Rods are a little longer and leaner than cones but have the same basic structure. [[Opsin]]-containing disks lie at the end of the cell adjacent to the [[retinal pigment epithelium]], which in turn is attached to the inside of the [[sclera|eye]]. The [[disc shedding|stacked-disc structure]] of the detector portion of the cell allows for very high efficiency. Rods are much more common than cones, with about 120 million rod cells compared to 6 to 7 million cone cells.<ref>{{Cite web|url=http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html|title=The Rods and Cones of the Human Eye|website=hyperphysics.phy-astr.gsu.edu|access-date=25 April 2016}}</ref>

Like cones, rod cells have a synaptic terminal, an inner segment, and an outer segment.  The synaptic terminal forms a [[synapse]] with another neuron, usually a [[bipolar cell]]  or a [[horizontal cell]]. The inner and outer segments are connected by a [[cilium]],<ref name="Kandel"/> which lines the distal segment.<ref>"Photoreception" ''McGraw-Hill Encyclopedia of Science & Technology'', vol. 13, p. 460, 2007</ref>  The inner segment contains [[organelle]]s and the cell's [[nucleus (cell)|nucleus]], while the rod outer segment (abbreviated to ROS), which is pointed toward the back of the eye, contains the light-absorbing materials.<ref name="Kandel"/>

A human rod cell is about 2 microns in diameter and 100 microns long.<ref>{{Cite web|url = http://book.bionumbers.org/how-big-is-a-photoreceptor/|title = How Big Is a Photoreceptor|website = Cell Biology By The Numbers|publisher = Ron Milo & Rob Philips}}</ref> Rods are not all morphologically the same; in mice, rods close to the outer plexiform synaptic layer display a reduced length due to a shortened synaptic terminal.<ref>{{cite journal |title=Morphological Diversity of the Rod Spherule: A Study of Serially Reconstructed Electron Micrographs |first1=Shuai |last1=Li |first2=Joe |last2=Mitchell |first3=Deidrie J. |last3=Briggs |first4=Jaime K. |last4=Young |first5=Samuel S. |last5=Long |first6=Peter G. |last6=Fuerst |date=1 March 2016 |journal=PLOS ONE |volume=11 |issue=3 |pages=e0150024 |doi=10.1371/journal.pone.0150024 |pmid=26930660 |pmc=4773090|bibcode=2016PLoSO..1150024L |doi-access=free }}</ref>