Ganong's Review of Medical Physiology, 23rd Edition

CHAPTER 12

Vision 183

FIGURE 12–2
Neural components of the extrafoveal portion of the retina.
C, cone; R, rod; MB, RB, and FB, midget, rod, and flat bipolar
cells; DG and MG, diffuse and midget ganglion cells; H, horizontal cells; A, amacrine cells.
(Modified from Dowling JE, Boycott BB: Organization of the primate
retina: Electron microscopy. Proc R Soc Lond Ser B [Biol] 1966;166:80.)

FIGURE 12–3
Retina seen through the ophthalmoscope in a normal human. (a)
A photograph and
(b)
an illustration of the optic fundus
(back of the eye). Optic nerve fibers leave the eyeball at the optic disc to form the optic nerve. The arteries, arterioles, and veins in the superficial
layers of the retina near its vitreous surface can be seen through the ophthalmoscope.
(From Fox SI,
Human Physiology.
McGraw-Hill, 2008.)

C C C C

R R R R R

H

MB

MG DG MG DG

RB MB RB

FB

FB

A A

Pigment epithelium

Rod and cone

Outer nuclear layer

Inner nuclear layer

Outer plexiform layer

Inner plexiform layer

Ganglion cell layer

Optic nerve fibers

Outer segments

Inner segments

Arteriole

Venule

Optic

disc

Macula

lutea

Fovea

centralis

(a) (b)