Ocular Anatomy: Retina Overview

Three Tunics of the eye

Fibrous Tunic

Uveal/Vascular Tunic

Nervous Tunic

Fibrous tunic

cornea

limbus

sclera

Uveal/vascular tunic

iris, ciliary body, choroid

Nervous Tunic

sensory retina

RPE

_____ is anterior to the retina

ciliary body

_____ is internal/inner to the retina

vitreous

_____ is posterior to the retina

optic nerve

_____ is external/outer to the retina

choroid

Gross anitomical landmarks in the retina

optic nerve

macula

ora serrata

arteries

veins

Draw anoromical regions fo the retina and the layers

the sensory retina contains

everything but RPE

Path of light into the eye

cornea, aqueous humor, pupil, lens, vitreous humor, through retina to outer segment of photoreceptors in retina !!!

Path of impulse

-Photoreceptor (generator potential)

-Bipolar neurons (generator potential)

-Ganglion neurons (action potential)

-Optic nerve (action potential)

-Optic chiasma (action potential)

-Optic tract (action potential)

-Brain

First Order Neurons

Rods and cones

Rods and cones

special cells that contain photpigments that absorbs photons of light

Rods

good for dim illumination (scotopic vision)

Cones

good for well lit illuimation (photopic vision)

Photoreceptors contribute to

•Photoreceptor Layer

•ELM

•Outer Nuclear Layer

•Outer Synaptic/Plexiform Layer

Second order neurons

Bipolar cells

Bipolar cells

the dendrite synapses with photoreceptors and horizontal cells

axon synapses with ganglion or amacrine cells

relays info from photoreceptors to ganglion cells and receive feedback from amacrin cells

Bipolar cells contribute to

•Outer Synaptic/Plexiform Layer

•Inner Nuclear Layer

•Inner Synaptic/Plexiform Layer

Third order Neurons

Ganglion cells

Ganglion cells

dendrite picks up signals from bipolar and amacrine cells in the inner plexiform layer

axon emerges from ganglion cell layer and turns parallel to retina surface to form nerve fiber layer

synapses in the lateral geniculate nucleus

ganglion cells contribute to

•Inner Synaptic/Plexiform Layer

•Ganglion Cell Layer

•Nerve Fiber Layer

Internuerons

horizontal cells

amacrine cells

interplexiform cells

horizontal cells

transfer info horizontally along retinal surface

one axon leads to several dendrites in the outer synaptic/plexiform layer

•Helps integrate photoreceptors with bipolar cells that are not direct neighbors

horizontal cells contribute to

•Outer Synaptic/Plexiform Layer

•Inner Nuclear Layer

amacrine cells

have projections that act as both dendrites and axons

connect information from axons of bipolar cells, dendrites of ganglion cells and processes of interplexifrom layer

amacrine cells contribute to

•Inner Nuclear Layer

•Inner Synaptic/Plexiform Layer

interplexiform cells

has processes that extend into both the inner and outer synaptic layer

provides feeback from inner to outer retina

interplexiform cells contribute to

•Outer Synaptic/Plexiform Layer

•Inner Nuclear Layer

•Inner Synaptic/Plexiform Layer

Muller cells

support tissue that creates a reticulum (network) to minimize extracellular space

muller cells contribute to

•ELM

•Outer Nuclear Layer

•Outer Synaptic/Plexiform Layer

•Inner Nuclear Layer

•Inner Synaptic/Plexiform Layer

•Ganglion Cell Layer

•Nerve Fiber Layer

•ILM

Microglial cells

support tissue

phagocytoic cells

increase in response to inflammation

can be found anywere! Wandering

Astrocytes

support retina capillaries and encircle nerve fibers

astrocytes contribute to

•Ganglion Cell Layer

•Nerve Fiber Layer

Internal Limiting membr