1176 



THE DIGESTIVE SYSTEM. 



be marked out into a number of small, slightly elevated, polygonal areas, arece gastricce, 

 by numerous linear depressions ; the mucous membrane is consequently said to be 

 mamillated (Fig. 927, A). These little areas, which measure from 1 to 6 mm. in 

 diameter, are beset with numerous small pits, foveolce gastricce, about '2 mm. wide, 

 which are the mouths of the gastric glands, and they are so closely placed that the 

 amount of surface separating them is reduced (particularly in the pyloric portion, where 

 the gland mouths are widest) to a series of elevated ridges, plicae villosce, resembling 

 villi on section. Although the gland mouths cannot be seen with the naked eye, a very 

 slight magnification is sufficient to show them clearly ; it is also possible to see the 

 gland tubes leading off from the bottom of each (Fig. 927, B). 



Minute Structure of the Mucous Coat. In structure the mucous coat consists of an 

 epithelial covering composed of long columnar cells, and of numerous tubular glands, glandules 



gastricw, which are prolonged out- 

 wards from this surface, and which 

 are enclosed in a delicate connective 

 tissue stroma, with some small lymph 

 nodules, noduli lymphatici gastrici. 

 The bases of the glands reach out- 

 wards to the lamina mnscularis 

 mucosae, a layer consisting of an ex- 

 ternal longitudinal and an internal 

 circular layer of plain muscle fibres. 

 Glandulse Gastricae. These con- 

 sist of a duct terminating in one or 

 more secreting tubules. The duct is 

 lined with columnar epithelial cells, 

 similar to those which cover the sur- 

 face of the mucous membrane. Three 

 varieties of glands are found in dif- 

 ferent regions of the stomach, and 

 are named from their position 



(1) Cardiac Glands. These 

 glands are situated close to the ceso- 

 phageal opening. The duct ter- 

 minates in a single long tubule, 

 which is lined with short columnar 

 granular cells. 



(2) Fundus Glands. In these 

 glands the duct terminates in one 

 or more tubules, lined with poly- 

 hedral cells, termed the chief or cen- 

 tral cells. At intervals, between this 

 layer of cells and the basement mem- 

 brane, are placed larger spheroidal 



Rugae 



Mamillae 



Mouths of 



gastric glands, 



with gland 



tubes at 



bottom 



Depression 



between two 



mamillae 



Mouth of 

 gastric gland ^j 



FIG. 927. Mucous MEMBRANE OF THE STOMACH. A, Natural 

 size ; B, Magnified 25 diameters. In A the rugae and the 



mamillated surface are shown. In B the gland mouths - 



(foveolse gastric*), with the gland tubes leading off from some cells, which stain more deeply as a 

 of them, and the ridges separating the mouths (plicae villosae) rule, termed the parietal or oxyntic 

 are seen. cells. These glands are found in the 



fundus and body of the stomach. 



(3) Pyloric glands are found in the pyloric portion of the stomach. These consist of a short 

 duct, terminated in a group of short but tortuous gland tubules. These tubules are lined with 

 short columnar or polyhedral cells, similar to the central cells of the fundus glands. 



Blood-vessels. The arteries of the stomach are all derived ultimately from the cceliac artery. 

 The gastric artery arises from this trunk direct. Having reached the lesser curvature and given off 

 an cesophageal branch, it divides into two large branches, which run, one on each side of the organ, 

 along this curvature, and join below with two similarly -disposed arteries derived from the right 

 gastric branch of the hepatic. From the two arches thus formed, four or five large branches pass to 

 each surface of the stomach, and soon pierce the muscular coat. Along the greater curvature several 

 smaller branches reach the stomach from the right and left gastro-epiploic arteries, which are 

 branches respectively of the gastro- duodenal and the splenic, and run in the gastro-colic ligament 

 close to its attachment to the stomach. Finally, four or five short gastric arteries, branches of the 

 splenic, are distributed to the fundus of the stomach, which they reach by passing forwards between 

 the layers of the gastro-lienal ligament. At first the arteries lie beneath the peritoneum ; very 

 soon, however, they pierce the muscular coat, which they supply, and, reaching the submucosa, 

 break up to form a close network of vessels. From these arise numerous small branches, which 

 enter the mucous membrane and form capillary plexuses around the glands as far as the surface. 



The veins begin in the capillary plexuses around the glands ; uniting, they form a network 

 in the submucosa, from which arise branches that pierce the muscular coat, and finally end in 

 the following veins : the right gastro-epiploic, which joins the superior mesenteric ; the left gastr 

 epiploic, and four or five veins corresponding to the short gastric arteries, which join the splenic 

 the coronary vein of the stomach, which runs along the lesser curvature from left to right, and joins 



