Biliary Tree and Gallstones Flashcards Preview

Year 2 - GI System > Biliary Tree and Gallstones > Flashcards

Flashcards in Biliary Tree and Gallstones Deck (32):
1

Describe the biliary tree.

Biliary canaliculi to
interlobular bile ducts to
septal bile ducts to
intrahepatic ducts to
right and left hepatic ducts to
common hepatic duct to
common bile duct

2

Where does the bile duct pass?

Passes behind the duodenum, through the head of the pancreas to join the main pancreatic duct, becoming the bile duct.
This then enters the duodenum at the major/minor duodenal papilla

3

Where is the gallbladder located?

In the gallbladder fossa on the inferior surface of the right lobe of the liver

4

What is the epithelial lining and function of the gallbladder?

Columnar epithelium
- concentrates bile by absorbing water and electrolytes

5

What is bile composed of?

Water
Bile acids
Bile pigments
Phospholipids
Cholesterol
Electrolytes

6

Describe the bile acid synthesis.

Derived from cholesterol in the hepatocyte. Cholic acid is the primary bile acid

7

Describe bile salt synthesis.

Cholic acid is conjugated to bile salts by the addition of an amino acid group (taurine or glycine) before active export. These are primary bile salts.

8

What forms secondary bile salts.

The action of intestinal bacteria (de-hydroxylation) of primary bile salts

9

What causes gallbladder contraction?

Vagal stimulation
CCK release into the duodenum
- causes by detection of luminal fat
- sphincter of Oddi relaxation

10

What causes gallbladder relaxation?

Sympathetic nerves
Gut hormones
- somatostatin
- VIP

11

What do the following and and prefixes mean?
Chol
Lith
Docho
Ang
itis
iasis

Chol = bile
Lith = stone
Docho = duct
Ang = vessel
itis = inflammation
iasis = process

12

What is the function of bile salts?

Promote emulsification and formation of micelles to help fat absorption
- fat soluble vitamins are absorbed
- facilitates cholesterol excretion by solubilising it in bile
Influences the intestinal metabolic pathways

13

What is the entero-hepatic circulation?

95% of bile salts are reabsorbed from the gut (6-8 times a day)
- they are reabsorbed by the terminal ilium by active transport into the portal vein

14

How do bile salts travel in the blood?

Bound to albumin because it's hydrophobic

15

What are the risk factors for gallstones?

The six F's
- female
- forty
- fat
- fertile
- family history
Caucasian
Low fibre diet
Inflammatory bowel disease

16

Name the three types of gallstones.

Cholesterol stones
Bile pigment stones
Mixed

17

Describe cholesterol stones.

Usually solitary
Oval and large (up to 3cm)

18

Describe bile pigment stones.

Usually multiple
Hard and irregular
Can be associated with chronic heamolysis (sick cell)

19

Describe mixed stones.

The most common (80%)
Multiple and multi-faceted
Has a laminated structure with layers of bile pigment, cholesterol and calcium salts

20

In gallstone pathogenesis there are three main events (that often occur toegther). What are they?

Cholesterol supersaturation
Biliary stasis
Increased bilirubin secretion

21

Describe the process of cholesterol supersaturation.

Cholesterol is normally solubilised in bile, but very high levels cause supersaturation.
This can be due to increased oestrogen or decreased bile salt levels.

22

When does biliary stasis occur?

Occurs during periods of fasting, starvation or prolonged enteral feeding

23

Describe what happens in increased bilirubin secretion.

Pigmented stones can develop in increased heamolysis or a failure in hepatic conjugation

24

What complications can gallstones in the gallbladder cause?

Acute cholecystitis
- can cause jaundice and abnormal LFTs
Empyema
Mucocele
Cancer
Biliary colic
- stone impacted in gallbladder
- pain when eating

25

What complications can gallstones in the common bile duct cause?

Obstructive jaundice
Cholangitits
Pancreatitis

26

What complications can gallstones in the small intestine cause?

Gallstone ileus

27

What are some of the casues of obstructive jaundice?

Choldocholithiasis
Pancreatic cancer
Pancreatitis
Cholangiocarcinoma
Benign bile duct stricture

28

What are the signs and symptoms of obstructive jaundice?

Pale stools and dark urine
Yellow sclera
Hepatomegaly
Itch
S/S of chronic liver disease
Palpable gallbladder

29

Where do gallstones commonly impact in the bile duct?

The ampulla of Vater

30

How do you diagnose a gallstone in the bile duct (choledocholithiasis)?

Ultrasound with or without EUS and MRCP to confirm

31

Treatment of gallstones in the bile duct?

- antibiotics if cholangitis
- ECRP to attempt stone removal (incision in the sphincter of Oddi to increase the diameter)
- cholecystectomy to prevent recurrence

32

What happens to the LFTs in obstructive jaundice?

- ALP increases early (with a GGP increase)
- bilirubin rises steadily (level suggests the duration of disease)
- coagulopathy is common in prolonged obstructive jaundice