Sphincter of Oddi

...This refers to a condition in which pain is caused by abnormal motility and tone of the gallbladder and biliary sphincter, even though there are no organic lesions such as gallstones, inflammation, or tumors in the biliary tract (gallbladder and bile duct). Smooth muscle tissue in the biliary tract is developed in the gallbladder, the terminal part of the common bile duct (sphincter of Oddi), and the junction between the gallbladder neck and the gallbladder duct (sphincter of Lütkens). It regulates the outflow of bile into the duodenum and the inflow and outflow of bile into the gallbladder by the contraction and relaxation of the gallbladder, the fluctuation and maintenance of the tone of the sphincter, and the coordinated action of the gallbladder and the sphincter. Pain is caused by hypermotility (excessive contraction) or hypotonia (excessive relaxation) of the gallbladder, hypertonia or hypotonia of the sphincter, and the lack of coordinated movement of the gallbladder and the sphincter. ...

*Some of the terminology that mentions the "sphincter of Oddi" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…胆道(胆囊と胆管)に胆石，炎症や腫瘍などの器質的病変がないにもかかわらず，胆囊や胆道括約筋の運動･緊張異常が原因で，疼痛を訴える病態を指す。胆道の平滑筋組織は，胆囊，総胆管末端部(オッディ括約筋)，胆囊頸部･胆囊管移行部(リュートケンズ括約筋)に発達しており，胆囊の収縮･弛緩の運動や括約筋の緊張状態の変動･保持，ならびに胆囊と括約筋の協調作用により胆汁の十二指腸への流出や胆囊内への流入･流出を調節している。疼痛は，胆囊の運動亢進(過度の収縮)や緊張低下(過度の弛緩)，括約筋の緊張亢進や緊張低下，ならびに胆囊と括約筋の協調運動の失調などによってもたらされる。…

※「オッディ括約筋」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報