Lecture 21- Eye Flashcards
(40 cards)
Layer of the retina:
Adjacent to choroid
Derived from outer (thinner) layer of optic cup
Pigmented epithelium
Layer of the retina:
Outer segment consists of rhodopsin-containing lamellae
Inner segment consists of areas of rods and cones possessing mito., RER, golgi, and glycogen (metabolically active)
Inner and outer segments of rods and cones
Layer of the retina:
Area at junction of inner and outer segments of rods and cones and outer nuclear layer
Includes adherens junctions btw rods and cones and mueller cells.
External limiting membrane
Layer of the retina:
Cell bodies of rods and cones
1st order neurons
Outer nuclear layer
Layer of the retina:
Area of synapses btw axons and rods and cones and dendrites of bipolar neurons and horizontal cells
Outer plexiform layer
Layer of the retina:
Cell bodies of bipolar cells (2nd order neurons), horizontal cells, amacrine cells and mueller cells
Inner nuclear layer
Layer of the retina:
Area of synapses btw axons of bipolar cells and dendrites of ganglion cells
Inner plexiform layer
Layer of the retina:
Cell bodies of ganglion cells (3rd order neurons)
Ganglion cell layer
Layer of the retina:
Axons of ganglion cells
” a bundle of axons”
Optic nerve layer
Layer of the retina:
Terminations of mueller cell processes and their basement membrane
Internal limiting membrane
- Adjacent to choroid
- Synthesize melanin
- Apical processes surround and protect outer segments of rods and cones (photosensitive areas)
- phagocytose and degrade lamllae from rods and cones
- connected via tight junctions to form blood-retina barrier.
- esterify Vit A. Used in formation of photosensitive pigments.
Pigmented epithelial cells
Conducting neurons that synapse w/ rods and cones
Extend from outer plexiform to inner plexiform
Bipolar cells -2nd order neurons
Interneurons that interconnect rods and cones with each other and with bipolar cells
Extend in outer nuclear and inner nuclear layers of retina
Horizontal cells
Interneurons that connect ganglion cells and bipolar neurons
In inner nuclear layer
Amacrine cells
- neuroglial cells that extend throughout retina
- form external limiting membrane via zonula adherens btw mueller cells and rods and cones
- internal limiting membrane is formed by the basement membrane of these cells
Also in inner nuclear layer
Mueller cells
Conducting neurons whose axons form the fibers of the optic nerve
Extend from inner PLEXIFORM layer to optic nerve layers
Ganglion cells
Yellow region surrounding fovea
Highest visual acuity
Macula lutea
Depression of visual axis
Highest density of cone cells - sharpest visual acuity
Lacks rod cells and capillaries
Fovea centralis
Lacks photoreceptors
Point where ganglion cells turn into optic nerve
“Blind spot” of retina
Optic disc
Use rhodopsin as photopigment
Rods
Use 3 different kinds of iodopsins as photopigments
Cones
Rods and cones composed of 4 elements:
Spherule (rod) or pedicele(cone)
Cell body
Inner segment
Outer segment
Inner segment of rods and cones consist of:
Mito. And other organelles
Cell body of rods/cones consists of:
Nucleus and short axon
