Human eye of the size of the pupil, regulation and suppression of the hormone melatonin and entrainment of the body clock. The eye is not shaped like a perfect sphere, rather it is a fused two-piece unit, composed of the anterior segment and the posterior segment. The anterior segment is made up of the cornea, iris and lens. The cornea is transparent and more curved, and is linked to the larger posterior segment, composed of the vitreous, retina, choroid and the outer white shell called the sclera. The cornea is typically about 11.5 mm (0.3 in) in diameter, and 1/2 mm (500
Development of the human cerebral cortex during neurogenesis at mouse E10.5 to E12.5. Of the six layers found within the cortex, "layer 1 is the most superficial layer of the cortex...composed of Cajal-Retzius neurons and pyramidal cortex cells." This layer is unique in the aspect that these cells migrate to the outer edge of the cortex opposed to the migration experienced by the other 5 layers. Layer one is also characterized by expression of reelin, transcription factor T-box brain 1, and cortical migratory neuronal marker. The second and third layers, or the External Granular layer and External Pyramidal layer respectively, are formed around mouse E13.5 to