the eye p. 2

The eye 2
The Retina :
The retina represents the innermost layer of the eye.
Layers of the Retina :
Ten layers of cells and their processes constitute the retina.
The ten layers of the retina, from outside inward, are :1. Retinal pigment epithelium : the outer layer of the retina, actually not part of the neural retina but intimately associated with it.
2. Layer of rods and cones: contains the outer and
inner segments of photoreceptor cells.3. Outer limiting membrane: the apical boundary of Müller’s cells.
4. Outer nuclear layer: contains the cell bodies (nuclei) of retinal rods and cones.
5. Outer plexiform layer: contains the processes of retinal rods and cones and processes of the horizontal, amacrine, and bipolar cells that connect to them.
6. Inner nuclear layer: contains the cell bodies (nuclei) of horizontal, amacrine, bipolar, and Müller’s cells.
7. Inner plexiform layer: contains the processes of horizontal, amacrine, bipolar, and ganglion cells that connect to each other.
8. Ganglion cell layer: contains the cell bodies (nuclei)
of ganglion cells.
9. Layer of optic nerve fibers: contains processes of ganglion cells that lead from the retina to the brain.
10. Inner limiting membrane: composed of the basal lamina of Müller’s cells.
Chambers of the Eye
The layers of the eye and the lens serve as boundaries for three chambers within the eye.
The chambers of the eye are the following :
• The anterior chamber is the space between the cornea and the iris.
• The posterior chamber is the space between the posterior surface of the iris and the anterior surface of the lens.
• The vitreous chamber is the space between the posterior
surface of the lens and the neural retina.
• The aqueous humor is the watery fluid located in the anterior and posterior chambers.
• The lens is a transparent, crystalline, biconvex structure suspended from the inner surface of the ciliary body by a ring of radially oriented fibers, the zonule of Zinn.
• The vitreous body is composed of a transparent gel substance
that fills the vitreous chamber.
The fluid component of the vitreous body is called the vitreous humor .