EYEBALL
The Inner Nervous (Retina) Coat:
1:It is the innermost layer of the eyeball.
2:It is located in the back of the eyeball and the only extended part of the brain that can be
viewed physically from outside.
3:It consists of an inner sensory (nervous) layer and outer pigmented layer.
4:The sensory rrrretina consists of the following layers.
● Inner limiting membrane: is a boundary between vitreous and ciliary body
● Nerve fiber layer: It is composed of the axons of the retinal ganglion cells which will
form the optic nerve.
● Ganglion cells layer: it is the retinal ganglion layer
● Inner plexiform layer: consist of axons of the bipolar cells and dendritic processes
of ganglion and amacrine cells.
● Inner nuclear layer: contain the cell bodies of bipolar,horizontal and amacrine cells
● Outer plexiform layer: consist of network of synapses between the dendrites of
horizontal cells and photoreceptor cells
● Outer nuclear layer: consist of cell bodies of the photoreceptor cell (rods and cones)
● External limiting membrane: it is the layer that separates photoreceptors cells from
their nuclei
● The layer of rods cones: are that receptors that convert the light into electrical
activity ( action potential)
5: Among these layers the three primary layers of the retina are the photoreceptor cell layer,
bipolar cell layer and ganglion layers.
6:Retinal pigment epithelium: it is cuboidal epithelial cells that are attached to the choroid.
FUNCTIONS:
● In the retina, the light energy is converted into the electric signals (action potential)
which is transmitted via the visual pathway to the occipital cortex. It consists of:
● The function of RPE is to provide nourishment to the visual cells. The layer consists
of a black pigment that prevents the reflection to the eyeball.
MACULA:
Macula is a round slightly oval shape, present in the center of the retina that is responsible
for maintaining high resolution of the visual image; it maintains the sharpness of the vision.
FOVEA:
Fovea is a small area composed of cones cells located in the middle of the macula that bring
sharpness to the visual image.
The Inner Nervous (Retina) Coat:
1:It is the innermost layer of the eyeball.
2:It is located in the back of the eyeball and the only extended part of the brain that can be
viewed physically from outside.
3:It consists of an inner sensory (nervous) layer and outer pigmented layer.
4:The sensory rrrretina consists of the following layers.
● Inner limiting membrane: is a boundary between vitreous and ciliary body
● Nerve fiber layer: It is composed of the axons of the retinal ganglion cells which will
form the optic nerve.
● Ganglion cells layer: it is the retinal ganglion layer
● Inner plexiform layer: consist of axons of the bipolar cells and dendritic processes
of ganglion and amacrine cells.
● Inner nuclear layer: contain the cell bodies of bipolar,horizontal and amacrine cells
● Outer plexiform layer: consist of network of synapses between the dendrites of
horizontal cells and photoreceptor cells
● Outer nuclear layer: consist of cell bodies of the photoreceptor cell (rods and cones)
● External limiting membrane: it is the layer that separates photoreceptors cells from
their nuclei
● The layer of rods cones: are that receptors that convert the light into electrical
activity ( action potential)
5: Among these layers the three primary layers of the retina are the photoreceptor cell layer,
bipolar cell layer and ganglion layers.
6:Retinal pigment epithelium: it is cuboidal epithelial cells that are attached to the choroid.
FUNCTIONS:
● In the retina, the light energy is converted into the electric signals (action potential)
which is transmitted via the visual pathway to the occipital cortex. It consists of:
● The function of RPE is to provide nourishment to the visual cells. The layer consists
of a black pigment that prevents the reflection to the eyeball.
MACULA:
Macula is a round slightly oval shape, present in the center of the retina that is responsible
for maintaining high resolution of the visual image; it maintains the sharpness of the vision.
FOVEA:
Fovea is a small area composed of cones cells located in the middle of the macula that bring
sharpness to the visual image.
