Bile And Biliary System

Question 1

Cck effects

Answer 1

1. Sphincter of oddi relaxes

2. Gallbladder contracts

Question 2

Secretin effect

Answer 2

Liver ductal secretion of bile

Question 3

Path of bile

Answer 3

Hepatocyte-> bile canaliculi-> bile ductules-> perilobular ducts-> interlobular ducts-> septal ducts-> lobar duct-> right and left hepatic -> common hepatic duct-> common bile duct-> ampulla of vater-> duodenum

Question 4

How are bile acids so concentrated?

Answer 4

In gall bladder, water is reabsorbed thanks to Na/H antiporter + na/k atpase + hco3-/cl-

Question 5

Bilirubin make up

Answer 5

From RBC
Fat soluble, toxic
Bound to albumin in blood
Bilirubin glucuronide formed in liver and secreted into blood

Question 6

Fate of fats post absorption

Answer 6

Lcfa-> TAG/phospholipids/esters of cholesterols in SER-> fat droplets form in SER-> apoproteins from RER transferred to SER to associate with lipid droplets-> VLDL & Chylomicrons to GA -> exocytosis -> lymphatic capillaries -> thoracic duct -> left subclavian vein
Glycerol/short chain FA / medium chain FA -> diffuse -> blood capillary

Question 7

Bilirubin secretion

Answer 7

Bilirubin dissociates from albumin -> enters hepatocytes-> glucuronidated into bilirubin mono/di glucuronide -> AT into gallbladder -> release into small intestine, where bilirubin glucuronide-> bilirubin -> uribilinogen (excreted by kidneys or…) -> stercobilin -> fecal excretion

Question 8

Gallstone causes

Answer 8

1. Too much absorption of water
2. Too much absorption of bile salts
   3, too much cholesterol in bile
3. Inflammation of epithelium

Question 9

What happens to bile salts after lipids are absorbed?

Answer 9

In liver (chylomicrons from circulation), chylomicrons split into tag and cholesterol-> cholesterol converted to bile acids -> conjugated bile acids -> gut-> reabsorbed (na+/at/ diffusion) or excretion