The Regulation of the Flow of Bile

The physiology of the gall bladder and the so-called resistance of the sphincter of Oddi have attracted considerable attention largely from a surgical point of view. Because of the pathology often encountered in the gall bladder and ducts, surgeons have been forced to make decisions regarding the functional significance of these structures and perhaps necessarily to draw conclusions with respect to the mechanism involved in the flow of bile into the intestine. The most recent reviews of the literature are those by Mann (1924a) and Chiray and Pavel (1925). I shall only mention here a few papers that embody the more or less common findings. The anatomy of the biliary tract has been studied by Oddi, Hendrickson, Mann, and Auster and Crohn. Oddi (1887) found in the dog near the mouth of the duct a muscular ring which after separation from the fibers that join the intestinal musculature could be considered as an independent sphincter. Hendrickson (1898) found some muscle fibers running around the end of the duct but for the most part the fibers along the duct were continuous with the intestinal musculature. Mann (1920), who studied several species of animals, was able to make out a definite arrangement of muscle fibers which might function as a sphincter. Auster and Crohn (1922) did not see a muscular bundle formation that might be called a sphincter. Microscopic observations upon preparations made from dogs and man indicated that the muscle fibers at the mouth of the common duct were "scanty, widely separated and diffuse and at no time continuous," They gained the impression that the muscular apparatus of the papilla is made up of a fusion of the fibers of the intestinal musculature with the corresponding layer of the duct. Oddi (1888) found this sphincter offered a resistance of 50 mm. Hg to fluids entering the lumen of the intestine. A resistance has been estimated and attributed to the sphincter by many observers since Oddi's work. Archibald (1919) reported similar findings. Mann (1919) ' recorded a minimal resistance in six species of animals possessing a gall bladder of 75 to 100 mm. water. Jacobsen and Gydesen (1922) found a resistance in dogs of 90 to 210 mm. water. Cole (1925) encountered 40 to 100 mm. water resistance in dogs.