LO15 - Gallbladder and pancreatic disease

Question 1

Describe the anatomy of the biliary tree

Answer 1

Bile canaliculi -> right and left hepatic ducts -> common hepatic duct -> joins with the cystic duct to form the common bile duct -> joins with the major pancreatic duct and drains into the duodenum at the major duodenal papilla

Question 2

Describe the composition of bile

Answer 2

• Bile salts:
o Bile acids are synthesised in the liver from cholesterol, and then form sodium and potassium salts in the alkaline hepatic bile.
o Bile acids help with fat digestion and absorption – they emulsify fats (these smaller fat molecules can be more thoroughly broken down by pancreatic lipase) and form micelles (which help transport fat to and through the intestinal mucosal membrane)
• Bile pigments: bilirubin and biliverdin (usually rapidly reduced to bilirubin)
o Waste product to be excreted
• Cholesterol
o No specific function known
o Even though cholesterol is almost completely insoluble in pure water, in the bile, the bile salts and lecithin combine with it to form soluble micelles.
• Other things: fatty acids, lecithin, fat, ALP

Question 3

Describe the factors that maintain cholesterol in solution

Answer 3

o Even though cholesterol is almost completely insoluble in pure water, in the bile, the bile salts and lecithin combine with it to form soluble micelles.

Question 4

List other conditions causing bile duct obstruction

Answer 4

• Intrinsic and extrinsic tumours eg cholangiocarcinoma
• Primary sclerosing cholangitis
• AIDS cholangiopathy
• Acute and chronic pancreatitis
• Strictures after invasive procedures
• Certain parasitic infections eg ascaris lumbricoides

Question 5

Discuss the clinical features of pancreatic neoplasms

Answer 5

Pancreatic cysts are often asymptomatic and an incidental finding. Symptoms when present can include
• Abdominal discomfort
• Nausea, vomiting
• Bile duct obstruction -> jaundice
• Gastric outlet obstruction
• Recurrent pancreatitis (due to intermittent obstruction of the pancreatic duct)
• Palpable mass
• Weight loss and other symptoms of malignancy
• Functioning endocrine tumours:
o Insulinomas: episodic hypoglycaemia -> confusion, visual change, unusual behaviour, palpitations, diaphoresis, tremulousness
o Gastrinomas: PUD, diarrhoea
o Glucagonoma: necrolytic migratory erythema, cheilitis, DM, anaemia, weight loss, diarrhoea, DVT, neuropsych symptoms
o VIPoma: hypokalaemia, hypochlorydria

Question 6

Discuss the complications of pancreatic neoplasms

Answer 6

• Bile duct obstruction
• Gastric outlet obstruction
• Recurrent pancreatitis