524 



THE TISSUES. 



Fig. 351. 



muscular fibres in its lowest portion, above which all is areolar tis- 

 sue. The muscular layer and the simple conoidal epithelium are 

 everywhere of the same thickness, while the intermediate portion 

 the glandular layer varies. 



The most important element of the gastric mucous membrane 

 the gastric glands are straight tubes passing through the membrane 



down to its muscular layer, and there- 

 fore varying in different parts from ^ to 

 % of an inch in length. They are so 

 crowded together that very little tissue 

 intervenes between them. (Fig. 351.) 

 They commence on the surface as cylin- 

 drical tubes 4^^ to 3 oV^ of an inch in 

 diameter, diminish below to go 1 ^ f an 

 inch, or less; and the most common form 

 terminates in a flask-shaped enlargement 

 f 4 FIT to T ^g of an inch. Each tube is 

 lined through its upper third by a simple 

 conoidal epithelium; but in the rest of 

 its extent the tube is entirely filled with 

 pale, finely granular, nucleated cells, 

 2^W to i 2 Vtf of an inch in diameter, 

 which do not seem to constitute a dis- 

 tinct epithelium. They are termed the 

 peptic cells ; and these are the simple pep- 

 tic glands occurring in the middle zone 

 of the stomach. The compound peptic 

 glands (Fig. 352, c) occur in the narrow 

 cardiac zone of the stomach. They resemble the preceding, except 

 that they divide into two or three, and then into four to seven 

 equally long cylindrical tubules, also lined by the peptic cells; in 

 which oil-globules are frequently observed. The terminal lobules 

 have a twisted appearance dependent on numerous lateral dilata- 

 tions. Smooth muscular fibres are also found between these glands. 

 Still, other compound tubular glands also exist in the pyloric zone, 

 resembling the last, except that they are larger and lined throughout 

 by a conoidal epithelium, and therefore contain no peptic cells. 

 (Fig. 352, B.) 



It is pretty certain that the true gastric juice is afforded only by 

 the two forms of peptic glands just described; while the last men- 



Perpendicular section through the 

 tunics of the pig's stomach, from the 

 pylorus, a. Glands. 6. Muscular 

 layer of mucous membrane, c. Sub- 

 mucous tissue (tunica nerved) with 

 divided vessels, d. Transverse mus- 

 cular layer, e. Longitudinal mus- 

 cular layer. /. Serous membrane. 

 Magnified 30 diameters. (Kulliker.) 



