354 



THE STOMACH. 



Fig. 248. 



form, for, though simple near their orifices, they may, towards their 

 deep or closed extremity, be cleft into two or three, or even eventually 

 into six or eight branches (figs. 248 and 249). The glands have exter- 

 nally a basement membrane, composed of flattened cells joined edge to 

 edge, and with processes which on the one side join the retiform tissue 

 of the mucous membrane, and on the other side, more delicate, extend 

 in amongst and support the enclosed ei)itlielium cells.* 



Two kinds of glands are distinguished, 

 which differ from one another both in 

 the character of the enclosed cells, and, it 

 is believed, in the nature of their secretion. 

 Those of the one kind (fig. 249, m), which 

 are simpler in structure and fewer in 

 number than the others, and are found 

 most numerously in the pyloric region, are 

 lined throughout by an epithelium which 

 is continuous with and in many respects 

 similar to the columnar epithelium which 

 covers the general surface of the stomach 

 between the mouths of the glands. In the 

 deeper parts, however, of these pyloric 

 f/Iands — or mucous glands as they have 

 been termed from the supposed nature of 

 their secretion — the lining cells become 

 shorter and more cubical, and according 

 to Ebstein approach in character to the 

 " central " cells of the other glands. These, 

 which are commonly known as peptic glands, 

 are lined to a variable depth by the colum- 

 nar epithelium cells (fig. 248, a), which 

 are then (at the neck of the gland) suc- 

 ceeded by large spheroidal or ovoidal 

 coarsely granular cells, which have long 

 been known as " peptic " cells (fig. 248, c ; 

 fig. 249, p, 1). Towards the bottom (or 

 iylhe"'peptic* cells "r^"i "some of fioidiis) of the gland, however, the peptic 



Fig. 248. — Peptic Gastric 

 Glands from the Dog's 

 Stomach, magnified (from 

 Frey). 

 1, longitudinal view ; a, mouth 



of the gland ; b, one of the first 



tubular divisions of the gland ; 



<", the single tubes partly occupied 



the cells pressed out ; '^, cross 

 section near the mouth, showing 

 the epithelial lining ; 3, cross 

 section of the simple tubes, near 

 the neck of the gland. 



cells do not form a regular lining, but are 

 found only here and there (fig. 249, P, jj, 2) 

 producing generally an outward bulging 

 of the basement membrane where they 

 occur ; the rest of the tube is here occu- 

 pied, except a small channel left along the middle, by finely granular, 

 polyhedral or angular cells, which, from their position, may be termed 

 the " central " cells of the gland (//). According to Heidenhain, these 

 extend up into the neck of the gland, and become continuous Avith 

 the columnar epithelium there. 



It is only quite recently that attention has been more especially di-awn to these 

 central cells (Heidenhain, RoUett). Fi'om the changes which they appear to 

 "undergo during the functional acti^dty of the stomach, Heidenhain was led to 

 infer that it is these cells, and not those ordinarily known as peptic cells, which 

 are concerned in the secretion of pepsin, hence he named them the principal ceUs 



* These sustentacular processes are much more developed in the gastric glands of some 

 animals (porpoise, pig) than in those of the human stomach (F. E. Schultze, Heidenhain). 



