Flashcards
Liver I
Cards in this deck (18)
- 1Where is the liver located and describe its gross structure- Situated underneath the diaphragm
- Most within rib cage
- Has a right lobe and left lobe - 2Describe the functions of the liver- Metabolism and substrate interconversion
- Protein synthesis e.g. plasma proteins
- Solubilisation, transport, storage and detoxification
-Protective and clearance
e.g. detox of ammonia
excretion of hormones ect. - 3Give the gross vascular and biliary components of the liver and the direction of flowhepatic artery - oxygenated blood form heart
hepatic portal vein - deoxygenated - nutrient rich blood from gut and spleen
BOTH drain into hepatic vein -> heart
Bile duct -> intestine
Together TRIAD - 4Describe what is unique about the blood flow to the liverIt has a parallel and series component
Hepatic artery - parallel from aorta - main oxygen supply (30%)
Portal vein - series has already been through spleen,gut+pancreas (70%) - nutrients and toxins - allows first pass metabolism e.g. glucose -> glycogen - 5Basic anatomy of liver and surrounding organsBile can bypass gallbladder and go straight to duodenum
- 6Describe the structure of a liver lobule- Blood from hepatic artery and portal vein travels towards the central vein
- perfusion of the hepatocytes by the sinusoids
- bile canals head towards the bile duct and caniliculli - 7Explain how hepatocytes link to the sinusoids and biliary system?Hepatocytes have a membrane facing the sinusoids and a membrane facing the bile canaliculi
- Hepatocytes take substances from sinusoids and modify them
- Create bile and transfer to bilary system for excretion - 8Describe the three functional arrangements of hepatocytesHepatic lobule - blood flow from triad to central vein
Portal lobule - bile flow from central vein to triad
Portal acinus - oxygen gradient from hepatic artery - highest (line bw triads) -> lowest (ccentral vein) BEST - 9Descfribe the functional zonation of the portal acinushepatic artery -> zone 1 hepatocytes -> zone 2 hepatocytes -> zone 3 hepatocytes ->central vein
- Z1 - high 02, toxins and nutrients (GI)
-Z3 - low 02, high hepatocyte metabolites and toxins - 10Describe the differences between zone 1 and zone 3 hepatocytesZONE1 - amino acid catabolism, gluconeogenesis,glycogen degradation ect.(oxygen dependent processes)
ZONE 3 - liponeogenesis, glycolysis, glycogenesis, bile acid biosynthesis, biotransformation ect.
Different expression of enzymes - 11What determines what zone hepatocytes are in an what implication does this have when this is compromised?The direction of blood flow - if you reverse it Z1-> Z3 ect.
This means Z1 are most resistant to circ. compromise and nutritional deficiency and Z3 are least
Z1 first to regenerate - 12Describe the special features of the apical, basolateral and sinusoids.- apical membrane = canalicular membrane
has villi to increase diffusion and secretion
- BL - sinusoidal side villi to increase SA
- sinusoids have loose tight junctions
- these can be regulated but can allow cells through to the space of Disse (bw sinusoid epithelia and hepatocyte) - 13Give the overall mechanism of processing of compounds in the hepatocytes1) uptake of substance from space of Disse across BL membrane
2) transport within HC
3) modification by enzymes (sometimes)
4) excretion of substance or products into bile across A membrane or back into blood through BL membrane - 14Explain how the HC is involved in enterohepatic circulation- bile acids and salts are taken up by hepatocyte from blood and secreted into the biliary system
- allows constant re-circulation of bile acids and salts - 15What is hepatitis and what can cause it?Inflammation if the liver that triggers cell death - necrosis/apoptosis
- infection
-drugs/chemicals e.g. paracetomol
-inherited
-autoimmune
- non-alcoholic fatty liver (diabetes,hypertension and obesity) - 16Describe the three categories of hepatitis and what can cause them- Acute hepatitis
Inflammatory - often viral infection or poisons e.g. alcohol
- Chronic
Viral, autoimmune, drug, genetic disease
- Fulminant (hepatic failure)
Viral, poisons and toxins e.g death cap paracetomol, ischaemia/hypoxia - 17Describe the three categories of liver impairment and what causes themCholestasis (bile formation) - jaundice
e.g. biliary cirrhosis, hepatitis, drugs
Cirrhosis (scarring) - portal ht
e.g. infections, genetic, drugs
Extrinsic diseases
e.g. vascular, biliary duct obstruction, other - 18Describe what causes the clinical symptoms in liver disease and what liver functions they each impair- liver dysfunction
. energy generation and substrate interconversion, solubilisation, storage, loss of blood clotting, defence and excretion
- portal hypertension
. defence and excretion, renal homeostasis, GI hemorrhage
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- Physiology Flashcards on Liver I, created by Charlotte Pedley on 11/12/2018.
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- Charlotte Pedley
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