21. Inner coat of the eyeball, retina. Development of the eye Flashcards
Development of the eye
-> What happen during 5th week?
Eye will form a double-layerd eye cups
(inside retina pars nervosa, outside pigment epithelium - stratum pigmentosum)
Ocular cup stalk directs the optic nerve out of the retina towards the diencephalon
Development of the eye
-> 5th week
-> Eye will form ___
a double-layerd eye cups
(inside retina pars nervosa, outside pigment epithelium - stratum pigmentosum)
Development of the eye
-> 5th week
-> Ocular cup stalk directs the optic nerve out of the retina towards ___
the diencephalon
Characteristics of Macula lutea
- 4mm temporal to the disc n. optici
- Carotoids in outer segments → yellow
- Free from large vessels
Characteristics of fovea centralis
place of sharpest vision
INL and GL are thinner
Large cone density
Characteristics of Fovea
Only CONES (slim)
Avascular
DISTRIBUTION OF THE RETINA, TOPOGRAPHY
-> Identify
PARS OPTICA RETINAE
-> List the layers
Identify these cells in the retina
Name these 2 ways
What is the Vertical flow of information?
I: Photoreceptor
-> II: Bipolar cells
-> III: Ganglionic cells
Lateral flow of information
- Between photoreceptors: horizontal cell
- Between bipolar cells: amacrine cell
Lateral flow of information
- Between photoreceptors: horizontal cell
- Between bipolar cells: amacrine cell
What type of epithelium is STRATUM PIGMENTOSUM?
Single-layered cuboidal epithelium
What are the 3 characteristics of STRATUM PIGMENTOSUM?
- Modified basal membrane in the direction of the choroid = Bruch’s membrane
- Associated with zonules accludentes (blood-retina barrier)
- Direct photoreceptors: Microvilli (containing pigments, light absorption)
PHOTORECEPTORS OF THE RETINA
-> Identify
What does SYNAPTIC LAYER– STR. PLEXIFORME EXTERNUM contain?
- Cones
- Rods
- Ribbon Synapses
SYNAPTIC LAYER– STR. PLEXIFORME EXTERNUM
-> Characteristics of cones
- invaginating synapses (triad, 2 horizontal, 1 bipolar)
- flat synapses (bipolar)
- Gap junctions (between Photoreceptors)
SYNAPTIC LAYER– STR. PLEXIFORME EXTERNUM
-> Characteristics of rods
invaginating synapses (2 Horizontal, 1-3 Bipolar)
STR. GRANULOSUM INTERNUM
-> List the cells
SYNAPTIC LAYER – STR. PLEXIFORME INTERNUM
-> Synaptic layer between ___ and ____
Between Bipolar cells, Amarkin cells AND ganglionic cells
(Synaptic Dyads: Bipolar cells)
GRANULAR LAYER – STR. GANGLIONARE
-> Name 4 types of cells
- Ganglia cells
- Midget cells
- Parasol Ganglion cells
- Other ganglion cells
GRANULAR LAYER – STR. GANGLIONARE
-> What is the role of Ganglic cells
Ganglic cells → CGL (lateral geniculate nucleus (Cgl).)
In the direction of the macula in several rows
GRANULAR LAYER – STR. GANGLIONARE
-> The role of Midget cells
Connection to 1 cone Bipolar → CGL Pars parvocellularis Where? (general properties, movement
GRANULAR LAYER – STR. GANGLIONARE
-> The role of Other ganglion cells
background exposure, pupillary reflex “Displaced Amacrine Cells”
GRANULAR LAYER – STR. GANGLIONARE
-> The role of Parasol Ganglion cells
- Contributes to many bipolar (convergence)
- parasol ganglion cells contribute to the primary visual pathway via the magnocellular division of the lateral geniculate nucleus
What? (subtleties, contrast, color)
STR. NEUROFIBRARUM OR MEMBRANA LIMITANS INTERNA
-> What are characteristics of Str. neurofibrarum
- Axons of ganglion cells
- Non-myelinated nerve fibers
STR. NEUROFIBRARUM OR MEMBRANA LIMITANS INTERNA
-> What are characteristics of Lamina limitans interna
- Extensions of Müller cells
- Lamina basalis
Blood supply of Str. plexiforme ext.
Branches from the Art. centr. retinae reach only to the OPL.
The outermost layers (photoreceptors) are supplied by ___
diffusion from the choroid.
Branches from the Art. centr. retinae reach only to the OPL.
-> The outermost layers (photoreceptors) are supplied by diffusion from the choroid.
-> Photoreceptors are therefore particularly at risk in ___
retinal ablation.
