1166 



SPLANCHNOLOGY 



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 (fibres obliquce) 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 con- 

 tracted state of the organ it is thrown into numerous plaits or rugse, 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. 



--m/ni 



Fio. 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 mucosse. m'. Muscular tissue within the mucous membrane. 



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 witli 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 bv 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) com- 

 pound 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 



