Bile ( or 
gall) is a bitter, greenish-yellow 
alkaline fluid secreted by the 
liver of many 
vertebrates. It is stored in the 
gall bladder[?] between meals and upon eating is discharged into the 
duodenum where it aids the process of 
digestion, especially of 
fats. Besides its digestive function, bile serves as the route of excretion for 
hemoglobin breakdown products (
bilirubin) which give bile its colour. Bile also contains 
cholesterol, which occasionally accretes into lumps in the gall bladder, forming 
gallstones[?]
Yellow and black bile were two of the four vital fluids or humours of ancient and medieval medicine; for example, melancholia was believed to be caused by a bodily surplus of black bile.
Bile is also another name for 
Belenus, a god in 
Brythonic mythology.
 
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