Page 934 - Atlas of Histology with Functional Correlations

Holds retina in place against pigmented layer of the eyeball

Supports retina against shock and vibration

Retina

Contains three types of neurons distributed in different layers

Rods and cones are receptor neurons essential for vision that synapse with
bipolar cells
Bipolar cells connect to ganglion cells, from which axons converge
posteriorly at optic papilla
Area of optic papilla contains only axons of optic nerve and is the blind spot

Light rays pass through all cell layers to activate rods and cones
Pigmented layer of choroid next to retina absorbs light and prevents
reflection

Cells of pigmented layer form blood–retina barrier to isolated photoreceptive
cells

Choroid

Divided into suprachoroid lamina, vascular layer, and choriocapillaris layer
Suprachoroid layer contains connective tissue fibers and numerous
melanocytes
Vascular layer contains numerous blood vessels and melanocytes
Choriocapillaris layer contains capillaries with large lumina

Innermost layer of choroid is glassy membrane and lies adjacent to pigment
cells
Pigment cells separate choroid from retina and perform important functions

Pigment cells are phagocytic, store vitamin A, and form visual pigments for
rods and cones

Rods and Cones

Rods are highly sensitive to light, function in low light, and synthesize visual
pigment rhodopsin
Cones are sensitive to bright light, essential for visual acuity and color vision
Cones are most sensitive to red, green, or blue color spectrums and contain

visual pigment iodopsin

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