Human physiology . eninth hour of digestion, the chief cells are reduced and grow moreturbid, while the lining cells remain large or become still moreswollen. At the fifteenth hour the cells begin gradually to resumethe appearance and characters which they exhibited during hunger. 120 PHYSIOLOGY CHAP. These phenomena noted on the dog were confirmed for man, asshown in Figs. 39 and 40. Langley repeated these observations on fresh preparations ofthe gastric mucous membrane, and noted changes which, althoughdifferent, lead to the same interpretation as that of abstinence the chief c
Human physiology . eninth hour of digestion, the chief cells are reduced and grow moreturbid, while the lining cells remain large or become still moreswollen. At the fifteenth hour the cells begin gradually to resumethe appearance and characters which they exhibited during hunger. 120 PHYSIOLOGY CHAP. These phenomena noted on the dog were confirmed for man, asshown in Figs. 39 and 40. Langley repeated these observations on fresh preparations ofthe gastric mucous membrane, and noted changes which, althoughdifferent, lead to the same interpretation as that of abstinence the chief cells are strongly and uniformly granular;during digestion they become clearer, and are differentiated intotwo zones, the outer of which (f or ^ the cytoplasm) does notexhibit granules, which only appear in the inner zone. Since, aswe shall see, the extracts of gastric rnucosa contain more pepsin i¥P?P??f»/^-HM^^ IS •A W3^ffl»f^l^wa-;v x</7,:v\-¥iVda:^ y^2 -• vv^1-. FIG. 40.—Cross-section of caidiac glands during digestion. (Bohmandv. Davidoft.) V. References as in Fig. 39. and chymosin, according as the number of granules in the chiefcells of the fundus and pyloric glands is greater, this confirms thetheory which attributes the formation of the enzymes of thegastric juice to these cells. The granules seen in the cells of the gastric gland in thefresh state do not, however, represent the enzymes of the gastricjuice, but contain the zymogens, the proteins from which pepsinand chymosin are formed during the process of secretion. Schiff first recognised that active pepsin comes from thetransformation of an inactive substance found in the gland cells,which he called propepsin. The experiments of Ebstein andGriitzner confirmed this theory. They gave the name of pepticzymogen or pepsinogen to the inert substance which is convertedinto pepsin. They found that in a watery, non-acidulated, orglycerol extract of gastric mucosa, a certain amount of p
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectphysiology, bookyear1
