302 



STRUCTURE OF THE PANCREAS. 



Abnormal development of gases, in cases of gastric catarrh, occurs only when 

 the reaction of the gastric contents is neutral. Thus, in the presence of butyric- 

 acid fermentation, hydrogen and carbon dioxid are produced, while acetic-acid and 

 lactic-acid fermentation generate no gases. Marsh-gas (CH 4 ) also is found; though 

 this can reach the stomach only from the intestine, as it can be produced only in 

 the absence of oxygen. Traces of hydrogen sulphid generated by the bacterium 

 coli commune are formed, at times in connection with benign dilatation of the 

 stomach and motor insufficiency. Yeasts and various bacteria are also found in 

 the stomach. 



STRUCTURE OF THE PANCREAS. 



The pancreas is a compound tubular gland with terminal alveoli 

 which constitute the chief portions of the gland. On the internal sur- 

 face of the membrana propria, formed of fibrillar tissue, lie the some- 

 what cylindrical-conical secreting cells, which consist of two layers: 

 (i) the smaller, parietal layer, which is transparent, lamellated, stri- 

 ated, and can be deeply stained by carmine, and (2) the internal layer 

 (Bernard's granular layer), which is deeply granular, and stains but 

 slightly. Between the two layers lies the nucleus. During the process 

 of secretion a visible transformation takes place continually in the cell- 

 substance ; the granules in the granular layer undergo solution and form 

 constituents of the secretion, while in the external layer the homo- 

 geneous substance is renewed, and is later again transformed into granu- 

 lar matter. This, in turn, again moves inward toward the lumen of the 

 alveolus. 



In detail there takes place in the first stage of digestion (from the sixth to 

 the tenth hour) a consumption of the granular inner zone and a growth of the 



FIG. 115. Changes in the Cells of the Pancreas in the Different Stages ol Activity: i, in the state of hunger; 

 2, in the first stage of digestion; 3, in the second stage; 4, with paralytic secretion. 



striated outer zone (Fig. 115, 2). In the second stage (from the tenth to the 

 twentieth hour) the inner zone of the swollen gland has increased greatly in size, 

 while the outer zone is much diminished (Fig. 115, 3). In the state of hunger the 

 latter again increases in size (Fig. 115, i). In the pancreas, yielding a para- 

 lytic secretion, and reduced in size, the inner zone of shrunken cells is almost 

 entirely lost. 



In consequence of increased secretion, some of the secreting cells undergo a 

 change, so that the acini form irregular collections containing many granules, and 

 have lost all resemblance to glandular acini. Entire cells are also destroyed during 

 the activity of the gland and new ones are again formed. 



The finest excretory ducts of the acini begin as intercellular secretory spaces. 

 With the alveolus there is connected an intercalary portion, constituted of flat 

 cells, and which develops in the center of every acinus. Then a sort of salivary duct 

 follows, without striated epithelium, as in the salivary glands. From the micro- 

 center of the cells of the excretory-duct system a ciliated flagellum, the "outer 

 thread," projects free into the lumen of the canal. 



The pancreatic duct, which possesses an axial course and as a rule empties 

 into the dtiodenum in common with the bile-duct, while a smaller branch of the 

 duct makes its entrance at a special papilla at a higher level, consists of an inner, 

 denser, and an outer, looser, wall of connective and elastic tissue, together with 



