Page 131 - Atlas of Histology with Functional Correlations

(1). The illustration shows the light-staining apical cytoplasm (1a) and the dark-

staining basal nuclei (1b) of the simple columnar epithelium (1). The epithelial
cells are in close contact with each other and are arranged in a single row. A thin,
connective tissue basement membrane (2, 9) separates the surface epithelium
(1) from the underlying collagen fibers and cells of the connective tissue (3, 10),
called the lamina propria. Small blood vessels (5), lined with endothelium, are

present in the connective tissue (3, 10).

In some areas, the surface epithelium has been sectioned in a transverse or
oblique plane. When a plane of section passes close to the free surface of the
epithelium, the sectioned apices (6) of the epithelium resemble a layer of

stratified, enucleated polygonal cells. When a plane of section passes through
bases (7) of the epithelial cells, the nuclei resemble a stratified epithelium.

The surface cells of the stomach secrete a protective coat of mucus. The pale
appearance of cytoplasm is caused by the routine histologic preparation of the
tissues. The mucigen droplets that filled the apical cytoplasm (1a) were lost

during section preparation. The more granular cytoplasm is located basally (1b)
and stains more acidophilic.

In an empty stomach, the stomach wall exhibits numerous temporary folds
(8) that disappear when the stomach is filled with solid or fluid material. Also,

the surface epithelium extends downward to form numerous indentations or pits
in the surface of the stomach called gastric pits (11), seen in both longitudinal
section and transverse section.

FIGURE 4.5 ■ Simple columnar epithelium: surface of the stomach. Stain:
hematoxylin and eosin. Medium magnification.

FUNCTIONAL CORRELATIONS 4.3 ■ Simple

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