Page 563 - Atlas of Histology with Functional Correlations

Region (Transverse Section)

The three histologic regions of the stomach are the cardia, the fundus and body,
and the pylorus. The fundus and body constitute the most extensive region in the
stomach. The stomach wall exhibits four general regions: mucosa (1, 2, 3),

submucosa (4), muscularis externa (5, 6, 7), and serosa (8).

The mucosa consists of the surface epithelium (1), lamina propria (2), and
muscularis mucosae (3). The surface of the stomach is lined with a simple
columnar epithelium (1, 11) that extends into and lines the gastric pits (10),
which are tubular infoldings of the surface epithelium (11). In the fundus, the

gastric pits (10) are not deep and extend into the mucosa about one fourth of its
thickness. Beneath the epithelium is the lamina propria (2, 12) that fills the
spaces between the gastric glands. A thin, smooth muscle muscularis mucosae
(3, 15), consisting of an inner circular and an outer longitudinal layer, forms the

outer boundary of the mucosa. Thin strands of smooth muscle from the
muscularis mucosae (3, 15) extend into lamina propria (2, 12) between the
gastric glands (13, 14) toward the surface epithelium (1, 11), which are
illustrated at a higher magnification in Figure 14.11, label 8.

The gastric glands (13, 14) are packed in the lamina propria (2, 12), occupy

the entire mucosa (1, 2, 3), and open into the bottom of the gastric pits (10). The
surface epithelium of the gastric mucosa, from the cardiac to the pyloric region,
consists of the same cell type. However, the cells in the gastric glands

distinguish the regional differences of the stomach. Two distinct cell types can
be identified in the gastric glands. The acidophilic parietal cells (13) are located
in the upper portions of the glands, whereas the basophilic chief (zymogenic)
(14) cells occupy the lower regions. The subglandular regions of the lamina
propria (2, 12) may contain either lymphatic tissue or small lymphatic nodules

(16).

The mucosa of the empty stomach exhibits temporary folds called rugae (9)
that form during the contractions of the muscularis mucosae (3, 15). As the
stomach fills, the rugae disappear and form a smooth mucosa.

The submucosa (4) lies inferior to muscularis mucosae (3, 15). In an empty
stomach, submucosa (4) can extend into the rugae (9). The submucosa (4)
contains dense irregular connective tissue and more collagen fibers (17) than the
lamina propria (2, 12). In addition, the submucosa (4) contains lymph vessels,

capillaries (21), large arterioles (18), and venules (19). Isolated clusters of

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