Gastric mucosa

Mucous membrane layer of the stomach From Wikipedia, the free encyclopedia

Gastric mucosa

The gastric mucosa is the mucous membrane layer of the stomach, which contains the gastric pits, to which the gastric glands empty. In humans, it is about one mm thick, and its surface is smooth, soft, and velvety. It consists of simple secretory columnar epithelium, an underlying supportive layer of loose connective tissue called the lamina propria, and the muscularis mucosae, a thin layer of muscle that separates the mucosa from the underlying submucosa.

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Gastric mucosa
Stomach
Section of mucous membrane of human stomach, near the cardiac orifice. X 45. c. Cardiac glands. d. Their ducts. cr. Gland similar to the intestinal glands, with goblet cells. mm. Mucous membrane. m. Muscularis mucosæ. m’. Muscular tissue within the mucous membrane.
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Identifiers
Latintunica mucosa gastris
MeSHD005753
TA98A05.5.01.027
TA22914
FMA14907
Anatomical terminology
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Diagram of the alkaline mucous layer in the stomach with mucosal defense mechanisms

Description

In its fresh state, it is of a pinkish tinge at the pyloric end and of a red or reddish-brown color over the rest of its surface. In infancy it is of a brighter hue, the vascular redness being more marked.

It is thin at the cardiac extremity, but thicker toward the pylorus. During the contracted state of the stomach it is thrown into numerous folds or rugae, which, for the most part, have a longitudinal direction. They are most marked toward the pyloric end of the stomach, and along the greater curvature, and are entirely obliterated when the organ becomes distended.

When examined with a lens, the inner surface of the mucous membrane presents a peculiar honeycomb appearance from being covered with funnel-like polygonal or hexagonal depressions which vary from 0.12 to 0.25 mm. in diameter. These are the ducts of the gastric glands, at the bottom of each may be seen one or more minute openings of the gland tubes. Gastric glands are simple or branched tubular glands that emerge on the deeper part of the gastric pits, and outlined by the folds of the mucosa.

Gastric glands

The gastric glands in the cardiac region of the stomach are known as cardiac glands. In the pyloric region the glands are known as pyloric glands, and in the rest of the stomach they are called gastric glands.[1]

Several types of endocrine cells are found in the gastric glands. The pyloric glands contain gastrin-producing cells (G cells); this hormone stimulates acid production from the parietal cells. Enterochromaffin-like cells (ECLs), found in the oxyntic glands release histamine, which also is a powerful stimulant of the acid secretion.

Surface

The surface of the mucous membrane is covered by a single layer of columnar epithelium. This epithelium commences very abruptly at the cardiac orifice, where there is a sudden transition from the stratified epithelium of the esophagus. The epithelial lining of the gland ducts is of the same character and is continuous with the general epithelial lining of the stomach.

The sodium-iodide symporter (SIP) is expressed in all the surface mucous cells (at the basolateral membrane) but not in the mucous neck cells. SIP mediates the transport of iodide from the bloodstream and secretes it into the gastric lumen where it is taken up in the gastric juice. Its role is not known but it has been shown to be absent in gastric cancer.[2]

Pathology

See also

References

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