PYLORIC GLANDS OF THE STOMACH. 



241 





The cardiac portion of the gastric mucous membrane consists of a number of microscopic 

 tubular glands placed side by side, the fundus-glands of Heidenhain, otherwise called peptic, 

 or cardiac. Several gland-tubes, which are wider below, usually open into the duct (fig. 182). 

 Each gland consists of a structureless membrana propria with anastomosing branched cells in 

 relation with it. The duct is short, about one-fifth of the whole tube, and is lined by a layer 

 of cells like those lining the stomach, while the secretory part of the tubes is lined through- 

 out by a layer of granular, short, small, polyhedral, or columnar 

 nucleated cells. These cells border the very narrow lumen, 

 and are called principal {Heidenhain), central (fig. 180, II, 

 a), or adelomorphous cells (adrjAos, hidden). At various places, 

 between these cells and the membrana propria, are large, oval, 

 or angular, well-defined, granular, densely reticulated, nucleated 

 cells, the parietal cells of Heidenhain, the delomorphous cells of 

 Kollett, or the oxyntic (acid-forming) cells of Langley (fig. 180, 

 II, h). They are most numerous in the neck of the glands, and 

 least so in the deep blind end of the tubes. These cells are stained 

 deeply by osmic acid and aniline blue, so that they are readily dis- 

 tinguished from the other cells. They bulge out the membrana 

 propria of the gland opposite where they are placed. The parietal 

 cells in man are said to reach to the lumen of the gland-tubes 

 (Stohr). Isolated cells are sometimes found under the epithelium 

 of the surface of the stomach, and occasionally in individual pyloric 

 glands. The fundus-glands are most numerous (about five millions), 

 and are of considerable size in the fundus. 



2. The pyloric glands occur only in the region of the pylorus, 

 where the mucous membrane is more yellowish- white in colour (fig. 

 181, A). These glands are generally branched at their lower ends, 

 so that several tubes open into a single duct [which, in contra- 

 distinction to the duct of the other glands, is wide and long, extend- 

 ing often to half the depth of the mucous membrane. The duct is 

 lined by epithelium like that lining the stomach, while the secretory 

 part is lined by a single layer of short, finely granular, columnar 

 cells, whose secretion is quite different from that of the cells lining 

 the duct. The lumen is well defined. Nussbaum has occasionally 

 found other cells, which stain deeply with osmic acid, between the 

 bases of these. The appearance of the cells differs according to 

 their state of physiological activity (figs. 183, 184). When they are 

 exhausted they are smaller and more granular, owing to the denser 

 reticulation of their network ; at any rate they are granular in pre- 

 parations hardened in alcohol (fig. 184). There are no parietal 

 cells. ] 



The glands are supported by very delicate connective-tissue 

 mixed with adenoid tissue (fig. 180). Below this are two layers, 

 circular and longitudinal, of non-striped muscle, the muscularis 



and from it fine processes of smooth muscular fibres pass up between groups of the glands 

 towards the free epithelial surface of the mucous membrane. Perhaps these processes are con- 

 cerned in emptying the glands. [In the gastric mucous membrane of the cat, there is a clear 

 homogeneous layer, which is stained red by picro-carmine, and placed immediately internal 

 to the muscularis mucosae. It is pierced by the processes passing from the muscularis mucosae.] 



Masses of adenoid tissue occur in the mucous membrane, especially near the pylorus, con- 

 stituting lymph-follicles, which are comparable to the solitary glands of the small intestine. 

 The lymphatics are numerous, and begin close under the epithelium by dilated extremities or 

 loops (fig. 182, d) ; they run vertically, and anastomose in the mucosa between the gland-tubes, 

 which they envelop in sinus-like spaces. They join large trunks in the mucosa ; another plexus 

 of large vessels exists in the sub-mucosa (Loven). 



[The Nerves. A plexus of non-medullated nerve-fibres and a few ganglion cells exist in the 

 muscular coat [Auerbach's], and another [Meissner's] in the sub-mucosa. ] 



The blood-vessels are very numerous. Small arterial branches, a, run in the sub-mucosa, 

 and ascend between the glands to form a longitudinal capillary network, c,c, under the epithe- 

 lium, and between its meshes the gland-ducts open, g. The veins gradually collect from this 

 horizontal capillary network, and run towards the large veins of the sub-mucosa, v. 



163. THE GASTRIC JUICE. Properties. The gastric juice is a tolerably 

 clear colourless fluid, with a strong acid reaction, sour taste, and peculiar character- 

 istic odour; it rotates the plane of polarised light to the left. It is not rendered 

 turbid by boiling, and resists putrefaction for a long time. Its specific gravity = 



Q 



Fig. 181. 

 A, Isolated pyloric gland, 

 (fig. 177, Mm.), 



