What does the Hepatic Portal Vein transport? And from where to where?
Poorly oxygenated blood GI tract (Splenic and Mesenteric Artery) --> Liver
What does the Hepatic Artery transport? And from where to where?
Oxygenated blood Aorta --> Liver
What does the Hepatic Vein transport? And from where to where?
All blood out of the liver Liver --> Inferior vena cava
What happens to things that are in the Central Vein?
It is emptied into the Hepatic Veins, and then into the Inferior Vena Cava
What is the name given to way that both the blood and bile flow in contrast with each other?
Describe what Liver Sieve Plates are
These are fenestrations that are aggregated into groups, allowing small/soluble substrates to move between the sinusoid and hepatocytes They are also called liver sinusoidal endothelial cells
What are the two secondary bile acids called? And how are they formed? (including the formation of the primary bile acids)
Deoxycholic Acid + Lithocholic Acid Primary bile acids are synthesised from cholesterol in the hepatocytes These are then converted to the secondary bile acids by bacteira in the gut (duodenum)
What is the process of converting amino acids/lactate to Glucose called? Also what is needed of the amino acids before this process can occur?
Glyconeogenesis The amino acids must be deaminated to remove toxic ammonium ions (so forming urea)
What does glycogenesis mean?
Glucose --> Glycogen
What does glycogenolysis mean?
Glycogen --> Glucose
What are the two primary bile acids?
Explain how bile is secreted?
There is an increase in AA and Cholecystokinin (CCK) in the duodenum
An increase in plasma CCK then causes the gall bladder to contract, and the sphincter of oddi to relax
This causes bile to flow into the duodenum
What are the two phases of the biotransformation of drugs in the body?
Phase 1 - Modification by oxidation, reduction and hydrolysis
Phase 2 - Conjunction to an acetate or sulphate
What is the purpose of bile salts?
They can form micelles to emulsify fats (due to hydrophobic/phillic parts)
When conjugated to AA they become water soluble (bile salts)
When somebody overdoses on paracetamol, what metabolic pathway occurs?
Cytochrome P450 converts it into N-acetyl p-benzoquinone imine (NAPBQI) --> which is highly toxic to the liver and kidneys
What is a Xenobiotic?
A substance that is not normally found in the body
What are the 4 primary roles of the liver?
Synthesis of Bile Salts - Plasma Proteins (albumin, clotting factors, globulins) - Glucose
Storage of glucose (as glycogen)
Host defence - Kupffer cells
What are Cholangiocytes?
Epithelial cells of the intra/extra-hepatic ducts of the billary tree