Henry Gray (18251861). Anatomy of the Human Body. 1918.
a circular ring, which projects into the lumen, and forms, with the fold of mucous membrane covering its surface, the pyloric valve. They are continuous with the circular fibers of the esophagus, but are sharply marked off from the circular fibers of the duodenum.
The oblique fibers (fibræ obliquæ) internal to the circular layer, are limited chiefly to the cardiac end of the stomach, where they are disposed as a thick uniform layer, covering both surfaces, some passing obliquely from left to right, others from right to left, around the cardiac end.
The areolar or submucous coat (tela submucosa) consists of a loose, areolar tissue, connecting the mucous and muscular layers.
The mucous membrane (tunica mucosa) is thick and its surface is smooth, soft, and velvety. In the 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 organ it is thrown into numerous plaits or rugæ, which, for the most part, have a longitudinal direction, and are most marked toward the pyloric end of the stomach, and along the greater curvature (Fig. 1050). These folds are entirely obliterated when the organ becomes distended.
FIG. 1053 Section of mucous membrane of human stomach, near the cardiac orifice. (v. Ebner, after J. Schaffer.) 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. (See enlarged image)
Structure of the Mucous Membrane.When examined with a lens, the inner surface of the mucous membrane presents a peculiar honeycomb appearance from being covered with small shallow depressions or alveoli, of a polygonal or hexagonal form, which vary from 0.12 to 0.25 mm. in diameter. These are the ducts of the gastric glands, and at the bottom of each may be seen one or more minute orifices, the openings of the gland tubes. The surface of the mucous membrane is covered by a single layer of columnar epithelium with occasional goblet cells. 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 (Fig. 1055).
The Gastric Glands.The gastric glands are of three kinds: (a) pyloric, (b) cardiac, and (c) fundus or oxyntic glands. They are tubular in character, and are formed of a delicate basement membrane, consisting of flattened transparent endothelial cells lined by epithelium. The pyloric glands(Fig. 1054) are found in the pyloric portion of the stomach. They consist of two or three short closed tubes opening into a common duct or mouth. These tubes are wavy, and are about one-half the length of the duct. The duct is lined by columnar cells, continuous with the epithelium lining the surface of the mucous membrane of the stomach, the tubes by shorter and more cubical cell which are finely granular. The cardiac glands(Fig. 1053), few in number, occur close to the cardiac orifice. They are of two kinds: (1) simple tubular glands resembling those of the pyloric end of the stomach, but with short ducts; (2) compound racemose glands resembling the duodenal glands. The fundus glands(Fig. 1055) are found in the body and fundus of the stomach; they are simple tubes, two or more of which