Anatomy and physiology of biliary tree

1. Anatomy of biliary tree Physiology of bile and the bile circulation. Hassan Alqarni 30-3-1434هـ 1 Benign Biliary Conditions

2. Gallbladder pear-shaped sac, about 7–10 cm long lying on the visceral surface of the right lobe of the liver in a fossa between the right and quadrate lobes Divided into four anatomic areas: fundus the corpus (body) the infundibulum the neck 30-3-1434هـ 2 Benign Biliary Conditions

3. Relations Anteriorly : The anterior abdominal wall and the inferior surface of the liver Posteriorly : The transverse colon and the first and second parts of the duodenum 30-3-1434هـ 3 Benign Biliary Conditions

4. 30-3-1434هـ 4 Benign Biliary Conditions

5. Blood supply : cystic artery usually a branch of the right hepatic artery (>90% of the time). always is found within the hepatocystic triangle, the area bound by the cystic duct, common hepatic duct, and the liver margin ( triangle of Calot ). When the cystic artery reaches the neck of the gallbladder, it divides into anterior and posterior divisions. 30-3-1434هـ 5 Benign Biliary Conditions

6. 30-3-1434هـ 6 Benign Biliary Conditions

7. Venous drainage : either through: small veins that enter directly into the liver large cystic vein that carries blood back to the portal vein (rarely) 30-3-1434هـ 7 Benign Biliary Conditions

8. lymphatic drainage nodes at the neck of the gallbladder . Frequently, a visible lymph node overlies the insertion of the cystic artery into the gallbladder wall. Nerve supply: vagus sympathetic branches that pass through the celiac plexus 30-3-1434هـ 8 Benign Biliary Conditions

9. Biliary ducts divided into: Intrahepatic extrahepatic 30-3-1434هـ 9 Benign Biliary Conditions

10. Bile ducts Intrahepatic formed from the larger bile canaliculi which come together to form segmental ducts. fuse close to the porta hepatis into right and left hepatic ducts. Extrahepatic right and left hepatic ducts the common hepatic duct cystic duct common bile duct or choledochus . The common bile duct enters the second portion of the duodenum through a muscular structure, the sphincter of Oddi 30-3-1434هـ 10 Benign Biliary Conditions

11. 30-3-1434هـ 11 Benign Biliary Conditions

12. 1 to 4 cm in length and approximately 4 m of diameter lies in : front of the portal vein to the right of the hepatic artery. The common hepatic duct is joined at an acute angle by the cystic duct to form the common bile duct. common hepatic duct 30-3-1434هـ 12 Benign Biliary Conditions

13. length is quite variable Variations of the cystic duct and its point of union with the common hepatic duct are surgically important. cystic duct 30-3-1434هـ 13 Benign Biliary Conditions

14. A. Low junction between the cystic duct and common hepatic duct B. Cystic duct adherent to the common hepatic duct C. High junction between the cystic and the common hepatic duct D. Cystic duct drains into right hepatic duct. 30-3-1434هـ 14 Benign Biliary Conditions

15. H. Cystic duct courses anterior to common hepatic duct and joins it posteriorly E. Long cystic duct that joins common hepatic duct behind the duodenum F. Absence of cystic duct. G. Cystic duct crosses posterior to common hepatic duct and joins it anteriorly . 30-3-1434هـ 15 Benign Biliary Conditions

16. about 7 to 11 cm in length 5 to 10 mm in diameter. The upper third ( supraduodenal ) The middle third ( retroduodenal ) The lower third (pancreatic) Runs obliquely downward within the wall of the duodenum for 1 to 2 cm before opening on a papilla of mucous membrane ( ampulla of Vater ). common bile duct CBD 30-3-1434هـ 16 Benign Biliary Conditions

17. The common bile duct enters the second portion of the duodenum through a muscular structure, the sphincter of Oddi 30-3-1434هـ 17 Benign Biliary Conditions

18. union of the common bile duct and the main pancreatic duct The follows one of three configurations: In about 70% unite outside the duodenal wall and traverse the duodenal wall as a single duct. In about 20%, they join within the duodenal wall and have a short or no common duct, but open through the same opening into the duodenum. In about 10%, they exit via separate openings into the duodenum. 30-3-1434هـ 18 Benign Biliary Conditions

19. The extrahepatic bile ducts are lined by a columnar mucosa with numerous mucous glands in the common bile duct. The arterial supply to the bile ducts is derived from the gastroduodenal the right hepatic arteries , with major trunks running along the medial and lateral walls of the common duct. The nerve supply to the common bile duct and the sphincter of Oddi is the same as for the gallbladder 30-3-1434هـ 19 Benign Biliary Conditions

20. PHYSIOLOGY 30-3-1434هـ 20 Benign Biliary Conditions

21. Bile Function Aid in the digestion and absorption of lipids and lipid soluble vitamins Eliminate waste products ( bilirubin and cholesterol) through secretion into bile and elimination in feces. 30-3-1434هـ 21 Benign Biliary Conditions

22. Bile Formation and Composition The liver produces bile continuously and excretes it into the bile canaliculi . Normally liver produce 500–1000 mL of bile a day. Bile is mainly composed of water, electrolytes, bile salts, proteins, lipids, and bile pigments. 30-3-1434هـ 22 Benign Biliary Conditions

23. The primary bile salts, cholate and chenodeoxycholate , are synthesized in the liver from cholesterol. They are conjugated there with taurine and glycine Bile salts are excreted into the bile by the hepatocyte and aid in the digestion and absorption of fats in the intestines. About 95 percent of the bile acid pool is reabsorbed and returned via the portal venous system to the liver, the so-called enterohepatic circulation. Five percent is excreted in the stool, leaving the relatively small amount of bile acids to have maximum effect. 30-3-1434هـ 23 Benign Biliary Conditions

24. 30-3-1434هـ 24 Benign Biliary Conditions

25. Absorption and Secretion In the fasting state, approximately 80 percent of the bile secreted by the liver is stored in the gallbladder Motor Activity after meal , cholecystokinin (CCK) is released from the duodenal mucosa in response to a meal. gallbladder empties 50–70 percent of its contents within 30–40 min. 30-3-1434هـ 25 Benign Biliary Conditions

26. Summary 30-3-1434هـ 26 Benign Biliary Conditions