摘要: The embryonic optic cup consists of two layers. The inner layer consists of the presumptive neural retina and nonpigmented layer of the ciliary epithelium. The outer layer comprises the presumptive retinal pigmented epithelium and... 展开 The embryonic optic cup consists of two layers. The inner layer consists of the presumptive neural retina and nonpigmented layer of the ciliary epithelium. The outer layer comprises the presumptive retinal pigmented epithelium and the pigmented layer of the ciliary epithelium. The pigmented and nonpigmented layers of the ciliary epithelium begin to differentiate ultrastructurally from the adjacent retinal pigmented epithelium and neural retina, respectively, by day four of development. By the sixth day of development, the pigmented and nonpigmented layers of the ciliary epithelium have acquired the morphological characteristics of fluid and electrolyte transporting cells. It is possible that the cells of the ciliary epithelium are secreting embryonic aqueous humor and are responsible, at least in part, for intraocular pressure in the chicken embryo. 收起