Visual System Flashcards
Retinal ganglion cells
Where optic nerve originates
Where neural activity is initiated and transmitted
Lamina cribrosa
Where the optic nerve converges and exit the eyeball
Optic foramen
The intraorbital portion of the nerve extends from the globe to here
The interneurons of the retina include
Bipolar cells, horizontal cells, amacrine cells
Retinal pigment epithelium
Functions to absorb excess light and thus to prevent light scatter by reflection, metabolic support to the rods and cones since there are no blood vessels in outer retina, blood-retinal barrier
Nerve fiber layer
Axons of retinal ganglion cells passing to the optic disc where they converge
Ganglion layer
Cell bodies of retinal ganglion cells
Inner plexiform layer
Synaptic zone containing processes of bipolar cells, amacrine cells and retinal ganglion cells
Inner nuclear layer
Cell bodies of horizontal, bipolar, amacrine and muller cells
Outer plexiform layer
Synaptic zone containing processes of rod and cone cells and of horizontal and bipolar cells
Outer nuclear layer
Cell bodies of the rod and cone cells
Receptor layer
The photosensitive outer segments and the inner segments of rod and cone cells
Blood supply for vision
Originates in internal carotid artery
Two systems supply the eyeball: central artery and vein of the retina and ciliary arteries and veins
Visual input to the lateral geniculate nuclei
Enter cranial vault by optic foramina, the two optic nerves join at optic chiasm, optic tracts convey nerve fibers primarily to the right and left lateral geniculate nuclei of thalamus and midbrain centers
Cortical areas for vision
The axons of neurons in the lateral geniculate nucleus project to the primary visual cortex, VI. This ascending pathway is known as the optic radiation
