Retina, Biology

Retina

As invagination of the optic vesicle carries on to form the double walled optic cup the two layers of the optic cup start to differentiate in different directions. Pigment is produced in the cells of the outer 1- cell thick layer that becomes the pigmented retina. The cells of the inner layer proliferate quickly, mainly in its germinal zone near the margin of the optic cup. From here the daughter -cells migrate into the deeper region of the inner layer raising its thickness.

These cells ultimately differentiate in a variety of cell types involving the light sensitive photoreceptor cells (cones and rods), glial cells, inter neurons (bipolar, horizontal, amacrine) and ganglion cells. Collectively these cells comprise the neural retina. The proliferation then occurs just only in the marginal zone of neural retina. Glial cells become the Muller's Fibers which make the packing tissue and the outer and inner limiting membranes on the outer and inner surfaces of the neural retina. The bipolar, horizontal and amacrine cells sense to connect the photoreceptor cone and rod cells along with each other and the ganglion cells via way of their axons and dendrites. The axons from the ganglion cells of the neural retina meet at the base of the eye to form the optic nerve that travels down the optic stalk and connects the neural retina along with the brain.

Posted Date: 1/29/2013 2:26:40 AM | Location : United States







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