Biliary secretion: Liver and Gallbladder function

Question 1

What are the components of Bile?

Answer 1

Bile salts, pigments (bilirubin), cholesterol, P-lipids, ions, and water

Question 2

What is Cirrhosis?

Answer 2

Chronic liver disease in which normal liver cells are damaged and replaced by scar tissue

• excessive alcohol intake is most common cause of this
• fatty liver
• steatohepatitis

Question 3

What does cholesterol get made into?

Answer 3

Choic acid and chenodeoxycholic acid

-at liver

Question 4

What does cholic acid get turned into?

Answer 4

deoxycholic acid by & alpha dehydroxylase

Question 5

What does chenodeoxycholic acid get turned into?

Answer 5

lithocholic acid

Question 6

What are the relative amounts of the four bile acids?

Answer 6

Cholic acid. chenodeoxycholic acid> deoxycholic acid> lithocholic acid

Question 7

What is the most important bile pigment?

Answer 7

bilirubin

-does not take part in micellar formation

Question 8

What ions are in bile?

Answer 8

Na, Cl, and HCO3

Question 9

What is the point of micelle formation called in the concentration of bile?

Answer 9

the critical micellar concentraion

-concentration of bile needs to be high for micelles to form

Question 10

How does bile get back to the liver?

Answer 10

ileum through the portal V.

Question 11

What stimulates the secretion of Ions and water into bile?

Answer 11

secretin

Question 12

What causes contraction of the gallbladder?

Answer 12

Ach and CCK

Question 13

What causes relaxation of the sphincter of Oddi?

Answer 13

CCK

Question 14

How does bile get across the apical membrane of enterocytes?

Answer 14

by two systems: NTCP and OATP

Question 15

What is NTCP?

Answer 15

Na-dependent transport protein, sodium taurocholate cotransporting polypeptide

Question 16

What is OATP?

Answer 16

Na-independent transport protein, organic anion transport proteins

Question 17

Where is the only spot in the GI tract where Bile acids are actively transported?

Answer 17

at the ileum

Question 18

What has a negative feedback ont he synthesis of bile?

Answer 18

high bile secretion because it increases the rate of return of bile acids tot he liver via portal blood

Question 19

What inhibits 7 alpha hydroxylase?

Answer 19

bile salts

Question 20

What would happen to bile synthesis if we resected the ileum?

Answer 20

it would increase a lot because none of it is getting back

Question 21

Is canalicular bile an ultrafiltrate of plasma?

Answer 21

yes

Question 22

What accompanies the secretion of bile acids?

Answer 22

the passive movement of cations into the canaliculus.

Question 23

What does secretin do in all of this?

Answer 23

stimulates the secretion of HCO3 and water fromt he ductile cells, resulting nin a significant increase in bile volume, HCO3 concentratio, and pH and a decrease in the concentration of bile salts

Question 24

What is almost all bile formation driven by?

Answer 24

bile acids

-only a small portion of bile is stimulated by secretin and secretd fromt he ducts

Question 25

What accounts for bile’s yellow color?

Answer 25

conjugated bilirubin, otherwise known as bilirubin glucuronide

Question 26

What happens at the Reticuloendothelial system (RES)?

Answer 26

Hb goes to biliverdin which goes to bilirubin

Question 27

Where does bilirubin become conjugated?

Answer 27

the liver

Question 28

What unconjugates bilirubin from glucuronide int he intestine?

Answer 28

bacteria

Question 29

What is physiological neonatal jaundice?

Answer 29

when the infant has a high level of unconjugated bilirubin in the blood during the first week of life

Question 30

What are the 2 main cuases of physiological neonatal jaundice?

Answer 30

bilirubin production is elveated because of increased breakdown of fetal erythrocytes
-low activity of UDP glucuronyl transferase, the enzyme responsible for binding bilirubin to gluruonic acid, thus making bilirubin water soluble

Question 31

What is jaundice?

Answer 31

the yellow color of skin which begins on the face and then moves down to the chest, belly area, legs, and soles of the feet
-they can be tired or feed poorly if that bad

Question 32

What is Gilbert’s syndrome?

Answer 32

when the uptake to the liver gets blockes

-unconjugated jaundice

Question 33

What is Crigler-Najjar syndrom?

Answer 33

when the conjugation of bilirubin gets blocked

• still unconjugated jaundice
• this could be Glibert’s too

Question 34

What is Dubin-johnson and Rotor syndromes?

Answer 34

when the secretion to bile gets blocked

-conjugated jaundice

Question 35

What is biliary tree obstruction

Answer 35

When we can’t pass bile at all..

-gallstones?

Question 36

What is hemolytic anemia?

Answer 36

form of anemia due to hemolysis

• breakdown of RBCs leads to Juandice
• any cause of hemolytic anemia would lead to increased production of bilirubin
• increased bilirubin level overwhelmed liver’s capacity to produce conjugated bilirubin, resulting in INCREASED UNCONJUGATED BILIRUBIN

Question 37

What is Gilbert syndrome?

Answer 37

-high levels of unconjugated bilirubin in the blood
mutation in gene that cod for UDP glucuronyltransferase found in liver cells
-a lot of ppl don’t have any signs or symptoms

Question 38

What is Crigler-Najjar syndrome?

Answer 38

also high levels of unconjugated bilirubin in the blood

• nonhemolytic jaundice
• also mutations in UDP enzyme
• 2 types: 1 is more severe…. NO FUNCTION OF ENZYME

Question 39

What is the form of brain damage caused by the accumulation of unconjugated bilirubin in the brain and nerve tissues?

Answer 39

Kernicterus

Question 40

What is the treament for Criggler Najjar?

Answer 40

phototherapy

-doesnt work as well past the age of 4

Question 41

What drug is used to treat type 2 Criggler Najjar to aid in the confugation of bilirubin?

Answer 41

Phenobarbitol

-does NOT work with type 1

Question 42

What is Dubin Johnson syndrome?

Answer 42

• elevated conjugated bilirubin in the serum without elevation of liver enzymes
• defect int he ability of hepatocytes to secrete conjugated bilirubin into the bile
• mutations in multidrug resistance protein 2 (MRP2)

Question 43

What color is the liver in Dubin Johnson?

Answer 43

Black

from the melanin-like things

Question 44

What are the symptoms of Dubin Johson?

Answer 44

mild jaundice throughout life

-usually the only symptom

Question 45

What is Rotor syndrome?

Answer 45

buildup of BOTH unconjugated and conjugated bilirubin in the blood, but the majority is conjugated
-similar to dubin johnson

Question 46

What genes are mutated in Rotor syndrome?

Answer 46

OATP1B1 and OATP1B3

• they normally transport bilirubin and other compounds from the blood into the liver so that they can be cleared from the body
• LIVER CELLS ARE NOT PIGMENTED* that’s dubin johnson

Question 47

what does light therapy do exactly?

Answer 47

turns the trans-bilirubin into the water soluble cis-bilirubin isomer

Question 48

What are gallstones?

Answer 48

concretions that form in the biliary system

Question 49

When do gallstones occur?

Answer 49

When there is excess in either pigment of bilirubin breakdown or cholesterol

Question 50

What is choledocholithiasis?

Answer 50

when small gallstones pass to the biliary duct getting stuck there

Question 51

What happens if the gallstone passes to the common bile duct and obstructs it?

Answer 51

jaundice… the conjugated one

Question 52

How can a gallstone cause pancreatitis?

Answer 52

if it gets to the entrance of the duct at the duodenum and obstructs it

Question 53

What are the 2 phases in the liver handling drugs?

Answer 53

• process them with cyt P450

- conjugate them to make them watersoluble so we can excrete them