Editing Gallbladder (section)

==Function==
{{Bile ducts and pancreas}}
The main functions of the gallbladder are to store and concentrate [[bile]], also called gall, needed for the digestion of fats in food. Produced by the liver, bile flows through small vessels into the larger [[hepatic duct]]s and ultimately through the [[cystic duct]] (parts of the [[biliary tree]]) into the gallbladder, where it is stored. At any one time, {{convert|30|to|60|ml|usoz}} of bile is stored within the gallbladder.<ref name=PHYSIOLOGY2005 />

When food containing fat enters the [[Gastrointestinal tract|digestive tract]], it stimulates the [[secretion]] of [[cholecystokinin]] (CCK) from [[I cell]]s of the duodenum and jejunum. In response to cholecystokinin, the gallbladder rhythmically contracts and releases its contents into the [[common bile duct]], eventually draining into the [[duodenum]]. The bile [[Emulsion|emulsifies]] fats in partly digested food, thereby assisting their absorption. Bile consists primarily of water and [[bile salt]]s, and also acts as a means of eliminating [[bilirubin]], a product of [[hemoglobin]] metabolism, from the body.<ref name=PHYSIOLOGY2005 />

The bile that is secreted by the liver and stored in the gallbladder is not the same as the bile that is secreted by the gallbladder. During gallbladder storage of bile, it is concentrated 3–10 fold<ref>{{Cite journal|url=https://www.cghjournal.org/article/S1542-3565(05)00369-1/pdf|title=Biliary Sludge Is Formed by Modification of Hepatic Bile by the Gallbladder Mucosa|last=KO|first=CYNTHIA|date=2005|journal=Clinical Gastroenterology and Hepatology|volume=3|issue=7|pages=672–8|doi=10.1016/s1542-3565(05)00369-1|pmid=16206500|s2cid=27488720 }}</ref> by removal of some water and electrolytes. This is through the [[active transport]] of sodium and chloride ions<ref>{{Cite journal|last1=Meyer|first1=G.|last2=Guizzardi|first2=F.|last3=Rodighiero|first3=S.|last4=Manfredi|first4=R.|last5=Saino|first5=S.|last6=Sironi|first6=C.|last7=Garavaglia|first7=M. L.|last8=Bazzini|first8=C.|last9=Bottà|first9=G.|date=June 2005|title=Ion transport across the gallbladder epithelium|journal=Current Drug Targets. Immune, Endocrine and Metabolic Disorders|volume=5|issue=2|pages=143–151 |pmid=16089346|doi=10.2174/1568008054064805}}</ref> across the epithelium of the gallbladder, which creates an [[osmotic pressure]] that also causes water and other electrolytes to be reabsorbed.<ref name=PHYSIOLOGY2005>{{cite book |last2=Hall |first=Arthur C. |last=Guyton |first2=John E.|title=Textbook of medical physiology|year=2005|publisher=W.B. Saunders|location=Philadelphia|isbn=978-0-7216-0240-0|pages=802–4|edition=11th}}</ref>

A function of the gallbladder appears to be protection against [[carcinogenesis]] as indicated by  observations that removal of the gallbladder ([[cholecystectomy]]) increases subsequent cancer risk.  For instance, a systematic review and meta analysis of eighteen studies concluded that cholecystectomy has a harmful effect on the risk of right-sided colon cancer.<ref>{{cite journal |vauthors=Mu L, Li W, Ren W, Hu D, Song Y |title=The association between cholecystectomy and the risk of colorectal cancer: an updated systematic review and meta-analysis of cohort studies |journal=Transl Cancer Res |volume=12 |issue=6 |pages=1452–1465 |date=June 2023 |pmid=37434692 |pmc=10331452 |doi=10.21037/tcr-22-2049 |doi-access=free }}</ref>  Another recent study reported a significantly increased total cancer risk, including increased risk of several different types of cancer, after cholecystectomy.<ref>{{cite journal |vauthors=Choi YJ, Jin EH, Lim JH, Shin CM, Kim N, Han K, Lee DH |title=Increased Risk of Cancer after Cholecystectomy: A Nationwide Cohort Study in Korea including 123,295 Patients |journal=Gut Liver |volume=16 |issue=3 |pages=465–473 |date=May 2022 |pmid=35502586 |pmc=9099388 |doi=10.5009/gnl210009 }}</ref>