liver stuff Flashcards
what is liver inflammation most often due to?
- obesity
- the metabolic syndrome
- alcohol excess
- nonalcoholic steatohepatitis
where is the liver situated?
-right hypochondrium
how many segments is the liver split into?
8
what allows individual segment surgery in the liver?
that each segment has its own portal pedicle (branch of hepatic artery, portal vein and bile duct)
what is special about the caudate lobe (lobe 1)?
- physiologically independant part of the liver, receives an independant blood supply from the portal vein and hepatic artery
- only part of the liver that is directly in contact with the inferior vena cava
where are lymphatics present?
-portal tracts
function of liver?
- protein metabolism (ablumin, blood clotting factors)
- carbohydrate metabolism
- lipid metabolism
what are hepatocytes?
-liver cells
what are the anterosuperior and the posteroinferior surfaces called?
anterosuperior- diaohragmatic surface
posteroinferior- visceral surface
what are the 4 main lobes of the liver?
- left
- right
- caudate
- quadrate
how does the liver receive nutrients?
-the portal vein delivers nutrient rich, deoxygenated blood from the stomach and intestines (75% of blood)
how does the liver receive oxygenated blood?
the left and right hepatic arteries branch off the aorta and supply the liver with oxygenated blood (only supplies 25% of blood)
how does blood leave the liver?
through the left, right and middle hepatic veins that join up the inferior vena cava
what are sinusoids?
-gaps between the hepatocytes that blood flows through from the hepatic artery + portal vein to the central vein
what makes up the portal triad?
- bile duct
- hepatic artery
- portal vein
where are portal triads located?
-on the corners of the hexagonal lobules of the liver
what are liver macrophages called?
Kupffer cells
where are Kupffer cells found?
-sinusoids
where is the perisinusoidal space?
-between hepatocytes and sinusoids
what produces bile?
-hepatocytes
what is the fibrous protective lining of the liver called?
External Glisson’s capsule
what are the stages of drug metabolism?
Phase 1
- oxidation
- reduction
- hydrolysis
Phase 2
-conjugation
Excretion
- renal
- faeces (bile)
- lungs
- sweat/tears
- milk, saliva
what is the role of phase 1 in drug metabolism?
- increase drug polarity
- new chemically reactive group permits conjugation
what is the role of phase 2 in drug metabolism?
- further increases polarity
- adds endogenous compound
- usually results in inactive products
what mediates the oxidation of lipid soludble drugs?
CYP450
what are the ‘True LFTs’?
- albumin
- bilirubin
- prothrombin time
The chemical markers that measure the livers ability to synthesise proteins
what does increased ALT indicate?
hepatucellular injury
what does increased AST indicate?
may be elevated in:
- liver injury
- MI
- pancreatits
- haemolytic anaemia
- renal or MSK disease
where is AST found?
- heart
- liver
- skeletal muscle
- kidneys
- brain
- RBC
what does increased ALP suggest?
cholestasis
what does increased GGT indicate?
- biliary obstruction
- liver and pancreas disease
- CV disease
- alcohol
what LFT changes are seen in hepatocellular injury?
increase ALT
increast AST
what LFT changes are seen in cholestasis?
increase ALP
increase GGT
what does AST< ALT indicate
-chronic liver disease
what does AST>ALT suggest?
- cirrhosis
- acute alcoholic hepatitis
what is diagnosis if transferases (AST or ALT) very high? (>1000)
-alomst certanly hepatitis
what does a AST:ALT ratio of >2 suggest?
alcohol
what will never occur to AST in chronic liver disease?
> 1000
when may albumin fall?
- cirrhosis
- nephrotic syndrome
- inflammation in acute phase temporarily decreases albumin
what can increase prothrombin time indicate?
-liver disease causing reduced production of clotting factors
what are the types of jaundice?
- pre hepatic
- hepatocellular
- post hepatic (obstructive)
what does AST increased 20x suggest?
acute cause
what does AST increased 5-10x suggest?
chronic cause
