Liver Structure/Function

Question 1

what are the main functions of the liver?

Answer 1

metabolism: carbs, AAs, lipids
storage: glycogen, vitamins, metals (Fe)
synthesis: proteins (albumin/clotting factors)
detoxification
bile production
immune functions

Question 2

briefly describe the components of the liver

Answer 2

vasculature, parenchymal liver cells, biliary system, CT matrix

arranged as portal tracts and parenchyma

Question 3

describe the vasculature of the liver

Answer 3

artertial supply: hepatic artery (30-40%) and portal vein (60-70%)
connecting sinusoids (allows hepatocytes to take in nutrients/drugs)
venous drainage: hepatic vein

Question 4

what is the portal triad?

Answer 4

hepatic artery, portal vein and bile ducts (in portal tract)
all enter and exit liver through the porta hepatis

Question 5

what are the portal vein and hepatic artery rich in?

Answer 5

portal vein - food product, broken down RBCs from spleen

hepatic artery - O2

Question 6

describe the structure of hepatocytes

Answer 6

lies in plates and cords
exchange material with blood at sinusoidal surface
sinusoidal surfaces = fenestrated (increase SA), lacks complete BM

contains 3 surfaces: sinusoidal, intercellular and canalicular

Question 7

what are thr parenchymal liver cells?

Answer 7

hepatocytes
endothelial cells
kupffer cells (macrophages in liver)
perisinusoidal cells (fat storing)
liver-associated lymphocytes

Question 8

what are the components of the liver CT?

Answer 8

liver capsule (surrounds liver)
portal tracts
parenchymal reticulin

Question 9

name the components of the biliary system

Answer 9

bile canaliculi
bile ductules
bile ducts

Question 10

name the 4 lobes of the liver

Answer 10

right
left
caudate
quadrate

Question 11

what 2 ligaments separate the right/left lobes of the liver?

Answer 11

round and falciform

Question 12

what are the components of bile?

Answer 12

bilirubin (haemoglobin breakdown product)
bile acids/salts (cholesterol based, detergent for lipid absorption)
mucin

Question 13

what is the three-fold definition of cirrhosis?

Answer 13

diffuse process, fibrosis and nodule formation

Question 14

what is cirrhosis?

Answer 14

chronic liver inflammation (nectoric/hepatitis) over many years
persistence of injury causing agent
fibrous scarring and hepatocyte regeneration
irreversible

Question 15

what are the causes of cirrhosis?

Answer 15

ALCOHOL/METABOLIC (hyperlipidaemia/obesity)
hepatitis (including viral A/B/C/D/E)
biliary disease
haemachromatosis (iron overload)

Question 16

what are the causes of hepatitis?

Answer 16

alcohol
metabolism
viral infections
autoimmune disease
biliary disease
drugs/toxins

Question 17

on a cellular level, what are the findings in a liver with cirrhosis?

Answer 17

nodule formation (more hepatocytes)
more CT (irregular)
more lymphocytes due to inflammation

Question 18

what are the complications of cirrhosis?

Answer 18

liver failure
portal hypertension - increased resistance to blood flow through liver increasing portal circulation pressure
hepatocellular cancer

Question 19

what are the complications of portal hypertension?

Answer 19

portal-systemic shunts/varices (enlarged blood vessels in oesopgahus)
ascites (fluid filled abdomen)
splenomegaly (enlarged spleen)

Question 20

what are the effects of liver failure?

Answer 20

altered intermediary metabolism (impaired urea/glycogen synthesis)
reduced albumin/transport proteins
coagulation disorders
reduced complement (infection prone)
jaundice
altered xenobiotic metabolism (drugs)
circulatory/endocrine disturbances