storage
Last reviewed 01/2018
When the sphincter of Oddi is tonically contracted between meals, bile cannot flow into the duodenum and instead passes into the gallbladder for storage. The sphincter pressure is typically 15mmHg at rest, but it rises to over 100mmHg several times per minute in a cyclical manner; in the absence of stimulation for relaxation, this exceeds the average resting pressure of 10mmHg in the gallbladder.
While in storage, the composition of bile is modified further. Sodium ions pass down a diffusion gradient to the outside of the gallbladder with accompanying water and chloride or bicarbonate. The bile left behind is of a smaller volume but increased concentration.