Expulsion of its Contents as a Function of the Gall Bladder.

Abstract

Since the introduction of methods that visualize the gall bladder, many opinions have been expressed as to the mechanism of its emptying. These can be divided into 2 groups: (a) that the gall bladder has a passive rôle in this process, and (b) that the gall bladder empties due to the contraction of its own musculature. We wish to present further evidence that expulsion of its contents is an inherent function of the gall bladder and acts independently of purely mechanical factors.

The chief extrinsic agencies suggested as causing the discharge of bile from the gall bladder are: (1) variations in intra-abdominal pressure, (2) intestinal peristalsis, (3) elastic recoil following relaxation of the common-duct sphincter, and (4) the washing out of the gall bladder by hepatic bile.

(1) The fact that the gall bladder may remain full for many days during fasting and that violent struggling associated with tube feeding in the cat produces no discharge of its contents 1 is sufficient evidence that variations in intra-abdominal pressure, within physiological limits, do not cause emptying of the gall bladder.

(2) Vigorous intestinal peristalsis produced by physostygmine as well as the normal movement of a barium meal through the intestine without effect upon the gall bladder containing iodized oil, 1 would seem to rule out intestinal peristalsis as a significant factor.

(3) Though the common duct be completely excluded, a fat meal will induce emptying of the gall bladder through a cannula in the cystic duct (Copher 2 ), or the cut end of the common duct (Boyden 3 ). Also in one of our cats whose gall bladder had been filled with iodized oil, the hepatic and common ducts were injected from the gall bladder after the ingestion of fat without the discharge of any of the oil inta the duodenum.