THE FILLING AND EMPTYING OF THE GALL BLADDER

As a result of the control of the flow of bile into the duodenum largely by tonus and movements of the duodenum, bile intermittently enters the gall bladder where it is concentrated and undergoes other changes. The gall bladder empties itself of its content through the cystic duct (1) by the washing out of its contents by bile from the liver, (2) by the elasticity or contractile mechanism of its walls, and (3) by variations of intraabdominal pressure due to respiratory movements, contiguous organs, etc. A fourth manner of emptying of the gall bladder is by absorption of a portion of its content through its walls. The gall bladder is never entirely empty but tends to come to a state of partial collapse, when its contents are under minimum pressure. We have been unable to demonstrate rhythmic contractions of the gall bladder due to its musculature. If they are present they may aid but they are not essential for its emptying or filling. Experimentally, in the dog, a rubber bag which was substituted for the gall bladder functioned in a manner very similar to that of the normal gall bladder as shown by cholecystographic studies. The concentrating function, however, was absent.