Human physiology . sumed for man that the intestinal chymeremains in the majority of cases for about 4 hours in the smallintestine, and about 22 hours in the large bowel (Nothuagel).The peristaltic movements which drive it onwards become pro-gressively slower in proportion as it descends into the lower partsof the small intestine. Along with this delay there is a constantlyincreasing condensation of the intestinal contents, in consequenceof the absorption of water, and of the absorbable constituents ofthe chyme. In proportion as the contents of the intestine assume 364 PHYSIOLOGY CHAP. a firme
Human physiology . sumed for man that the intestinal chymeremains in the majority of cases for about 4 hours in the smallintestine, and about 22 hours in the large bowel (Nothuagel).The peristaltic movements which drive it onwards become pro-gressively slower in proportion as it descends into the lower partsof the small intestine. Along with this delay there is a constantlyincreasing condensation of the intestinal contents, in consequenceof the absorption of water, and of the absorbable constituents ofthe chyme. In proportion as the contents of the intestine assume 364 PHYSIOLOGY CHAP. a firmer consistency, their colour, odour, and external charactersapproximate to those of the faeces. On reaching the lower end of the ileum, the substances whichhave accumulated and escaped absorption, are forced on by theperistaltic movements through the cleft of the ileocaecal valve,and pass into the large bowel. The lips of this cleft lie trans-verse to the caecum, and are so arranged that the distension of r— CO CO. ~-7? cz. FIG. 102.—The caecum in connection with the ileum and colon. (Lueiani.) The anterior externalwall of the caecum has been cut away to show the cleft and labra of the ileo-caecal valve, withthe orifice of the vermiform appendix, ci, fundus of caecum ; av, vermiform appendix ; ac,its opening into the cavity of the caecum ; il, last tract of ileum ; v and v, lower and upperlabva, which circumscribe the cleft of the ileo-caecal valve ; co and a/, tirst and second ascending colon. the caecum brings them together in the position of closure(Fig. 102). The watertight closure of the ileocaecal valve be-comes still more perfect when the peristaltic movements of thelarge intestine begin in the fundus of the caecum. The contentof the caecum is then voided into the colon without any possibilityof reflux of faecal matter into the ileum, because the increase ofintracaecal pressure applies the lips of the valve still more firmlytogether. This passage of the ex
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectphysiology, bookyear1
