NMS. Surgery

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Part IV ♦ Gastrointestinal Disorders

If You Hear/See

Think

Bleeding esophageal varices

Endoscopic banding

Pigmented stones

Hemolysis, hemoglobinopathies

Primary sclerosing cholangitis

Ulcerative colitis

Fever, RUQ pain, jaundice

Cholangitis

GENERAL PRINCIPLES Anatomy I. Liver (Fig 10-1)

A. Two lobes (left and right): Divided by interlobar fissure. B. Eight subsegments (1–8): Each with its own vascular supply and biliary drainage. C. Blood supply 1. Arterial supply (25%) a. Right and left hepatic arise from the common hepatic artery. b. A “replaced” left hepatic can come from the left gastric artery. c. A “replaced” right hepatic comes from the superior mesenteric artery. 2. Venous supply (75%): From the portal vein. 3. Venous drainage: Left, middle, and right hepatic veins. II. Gallbladder A. Sections: Fundus, body, infundibulum, neck. B. Histology: Does not have a submucosa; mucosa is columnar epithelium. C. Arterial supply: Cystic artery from right hepatic artery. III. Biliary tree (Fig 10-2) A. Common hepatic duct: Formed by right and left hepatic ducts. B. Common bile duct (CBD): Formed by cystic and common hepatic ducts. C. Pancreatic duct: Joins the CBD and enters the duodenum at the ampulla of Vater. D. Sphincter of oddi: Tonically contracted, allows the gallbladder to fill in a retrograde fashion. Physiology I. Metabolic: Detoxification, glycogenolysis, ammonia conversion, drug processing, gluconeogenesis, lipogenesis, and cholesterol synthesis. II. Synthetic: Synthesizes the majority of the proteins in the body. III. Bile production A. Amount: 250 mL to 1 L of bile is produced daily. B. Composition: Electrolytes and water, bile pigments, protein, lipids, phospholipids (e.g., lecithin), cholesterol, and chenodeoxycholic acid.