Liver Physiology And Disease

Question 1

Hepatic portal vein comes from

Answer 1

IMV, SMV and splenic vein

Question 2

Splanchnic circulation

Answer 2

Circulation of the GI tract

Question 3

Zone 1 of liver lobules, O2 status and specialised for

Answer 3

Periportal
Most oxygenated

Oxidative metabolism
Gluconeogenesis
Urea synthesis

Question 4

Zone 3 of liver lobules, O2 status and specialised for

Answer 4

Pericentral
Least oxygenated

Drug metabolism
Glycolysis
Lipogenesis

Question 5

Hepatocytes lie in a ‘cage’ of

Answer 5

Reticuloendothelial cells

Question 6

What are sinusoids, where do they drain

Answer 6

Vascular spaces, into the central vein - and subsequently hepatic vein

Question 7

4 major liver cell types

Answer 7

Hepatocytes
Endothelial cells
Kupffer cells
Lipocytes (stellate cells)

Question 8

What is the space of disse

Answer 8

Location in the liver between sinusoid and hepatocyte

Question 9

Name some major functions of the liver

Answer 9

Energy metabolism/substrate interconversion
Synthesis of plasma proteins
Drug metabolism and detoxification
Immune functions
Production of bile
Cholesterol processing
Excretion of bilirubin

Question 10

Plasma proteins synthesised by the liver

Answer 10

Albumin, fibrinogen, a1-antitrypsin, plasminogen, transferrin, thyroid binding globulin, prohormones

Question 11

The macrophages found in the liver are? Location? Function?

Answer 11

Kupffer cells, attached to endothelial cells lining, ingest bacteria by phagocytosis and release inflammatory mediators

Question 12

Function of gall bladder

Answer 12

Store and concentrate bile

Question 13

6 components of bile, components secreted by what

Answer 13

Bile salts (liver)
Lecithin (liver)
HCO3- (cholangiocytes)
Cholesterol (liver)
Bile pigments (liver)
Trace metals

Question 14

Route of synthesised bile

Answer 14

Into bile canaliculus drainage into bile duct

Question 15

Describe bile acid formation, conjugation, secretion and recycling

Answer 15

Synthesised from cholesterol –> primary bile acids. Conjugated with amino acids (taurine and glycine). Secreted into bile canaliculus. Recycled via entero-hepatic recirculation (95%) - as primary and secondary bile acids, 5% excreted in faeces.

Question 16

Where are bile acids reabsorped

Answer 16

Terminal ileum

Question 17

Components of the recycled bile salts

Answer 17

~75% as intact bile salts

~25% de conjugated by bacteria –> primary bile acids, some dehydroxylated by bacteria –> secondary bile acids

Question 18

4 functions of cholesterol

Answer 18

Plasma membrane component
Component of bile salts
Precursor to steroid hormones
Myelin

Question 19

How is cholesterol transported

Answer 19

Complexed with lipoproteins synthesised in the liver

Question 20

4 Function of bile salts

Answer 20

Emulsification of lipids
Elimination of cholesterol
Prevention of cholesterol precipitation in the gall bladder
Facilitates absorption of fat soluble vitamins

Question 21

Main bile pigment, where does it come from, how processed by the liver

Answer 21

Bilirubin, from breakdown of haem in the spleen and BM, conjugated with glucuronic acid exported into bile

Question 22

What happens to conjugated bilirubin

Answer 22

Converted by bacterial proteases to urobilinogen, 10% re uptake into portal vein eventually excreted by kidney, 90% excreted as faeces.

Question 23

3 components of the portal triad

Answer 23

Portal arteriole, portal venule and bile duct

Question 24

How does liver failure cause encephalopathy

Answer 24

Liver usually breaks down ammonia to urea, in liver failure increased levels of NH3, crosses BBB, causes brain oedema and cytotoxicity

Question 25

Signs of chronic liver disease

Answer 25

Spider naevi, clubbing, ascites, Palmer erythema, dupuytrens contracture, leuconychia, gynaecomastia, testicular atrophy, loss of body hair, capital medusae, splenomegaly, parotid enlargement, jaundice, oedema, muscle wasting

Question 26

2 Tests of liver distress

Answer 26

ALT/AST - hepatocyte damage | Alk phos/yGT - bile duct damage

Question 27

'True' tests of liver function

Answer 27

``` Prothrombin time Bilirubin (excretion) Albumin Urea/creatinine pH ```

Question 28

What can cause 'decompensation' in liver disease

Answer 28

Infection, toxins, trauma, drugs, variceal bleed

Question 29

Major causes of liver injury

Answer 29

Fat Alcohol Virus Iron

Question 30

NAFLD stands for

Answer 30

Non alcoholic fatty liver disease

Question 31

NASH stands for

Answer 31

Non alcohol steatohepatitis

Question 32

What causes jaundice

Answer 32

Failure of body to excrete bile, clinically apparent when bilirubin is twice normal (~34uM/L)

Question 33

What is cholelithiasis

Answer 33

Gallbladder stones

Question 34

What is choledocolithiasis

Answer 34

Bile duct stones

Question 35

What can blockage of the common bile duct/pancreatic duct cause

Answer 35

Gallstone pancreatitis

Question 36

3 layers of the gall bladder wall

Answer 36

Epithelium Lamina propria Fibromuscular layer

Question 37

Major component of gall stones

Answer 37

Cholesterol

Question 38

Surgical procedure for removal of gall bladder

Answer 38

Cholecystectomy

Question 39

Causes of pancreatitis

Answer 39

Idiopathic, gallstones, ethanol, trauma, steroids, mumps, autoimmune, scorpion/spider stings, hyperlipidaemia/hypercalcaemia, ercp, drugs First 4 most common

Question 40

2 types of pancreatic cancer

Answer 40

Adenocarcinoma and neuroendocrine tumour

Question 41

Name for bile duct cancer

Answer 41

Cholangiocarcinoma

Question 42

2 blood supplies to the liver

Answer 42

Hepatic portal vein and hepatic artery