Page 922 - Atlas of Histology with Functional Correlations

FIGURE 22.7 ■ Posterior eyeball: sclera, choroid, optic papilla, optic nerve,
retina, and fovea (panoramic view). Stain: hematoxylin and eosin. Medium
magnification.

FIGURE 22.8 | Layers of Choroid and Retina

(Detail)

The inner layer of the connective tissue sclera (10) is adjacent to the choroid,

which is subdivided into several layers: the suprachoroid lamina with
melanocytes (11), the vascular layer (1), the choriocapillaris layer (12), and
the transparent limiting membrane or glassy (Bruch) membrane.

The suprachoroid lamina (11) consists of fine collagen fibers, a network of

elastic fibers, fibroblasts, and melanocytes. The vascular layer (1) of the choroid
contains medium-sized and large blood vessels (1). In the connective tissue
between the blood vessels (1) are melanocytes (2) that impart a dark color to this
layer. The choriocapillaris layer (12) contains capillaries with large lumina. The

innermost layer of the choroid, the glassy (Bruch) membrane, lies adjacent to the
pigment epithelium cells (3) of the retina and separates the choroid and retina
(see Fig. 22.9).

The outermost layer of the retina contains the pigment epithelium cells (3)

whose basement membrane forms the innermost layer of the glassy (Bruch)
membrane of the choroid. The pigment cells (3) of the retina contain melanin
(pigment) granules in their cytoplasm.

Adjacent to the pigment epithelium cells (3) is a photosensitive layer of
slender rods (4) and thicker cones (5). These cells are situated next to the outer

limiting membrane (6) that is formed by the processes of supportive neuroglial
cells called Muller cells.

The outer nuclear layer (13) contains the nuclei of rods (4, 7) and cones (5,
7) and the outer processes of Muller cells. In the outer plexiform layer (14) are

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