Liver And Homeostasis Flashcards
How is the liver involved in storage?
It stores:
Iron
Fat soluble vitamins
Glycogen (converted into glucose)
How is the liver involved in regulation, synthesis and secretion?
Makes plasma proteins e.g albumin
Makes clotting factors
Produces cholesterol (makes steroid hormones etc)
Controls levels of fat, AA and glucose in blood
Manufactures bile
Makes urea
Produced heat (due to metabolic functions)
How is the liver involved in purification, transformation and clearance?
Breaks down aged RBC
Processes hormones
Processing digested food from the intestine
Neutralising/destroying drugs/toxins
How is the liver involved in fighting infection?
Specialised macrophages in the liver (kupffer cells) destroy any bacteria they come into contact with
What are the 3 processes of carbohydrate metabolism?
1) Glycogenesis
2) Glycogenolysis
3) Gluconeogenesis
What is Glycogenesis?
Stores excess glucose in the form of glycogen
Makes glucose from other sugars
What is Glycogenolysis?
Glycogen broken down to release glucose
What is Gluconeogenesis?
Glucose formed from protein and glycerol (from fat)
What is the process of protein metabolism?
Deamination and urea formation
Transamination- AA converted into other AA the body needs
Protein formation eg albumin
What is the process of fat metabolism?
Produces triglycerides, cholesterol and lipoproteins
Triglycerides converted to FA/glycerol when energy is needed
How is urea eliminated from the body?
Liver breaks down AA in protein into ammonia, carbon dioxide, water and energy
Ammonia is toxic to cells so the liver converts it to urea
Urea is then transported in the blood to the kidneys and eliminated in urine
What is the function of stellate cells?
Involved in fibrosis and formation of scar tissue in response to liver damage
What are the 3 vessels form the portal triad (found around edge of each lobule)?
1) hepatic portal vein
2) hepatic artery
3) bile duct
What is bile?
Dark greenish/browning fluid produced by the liver
pH 8
What are the 2 functions of bile?
1) emulsifies large fat particles in food into microscopic particles- increases SA so lipase enzymes secreted in pancreatic juice to digest lipids
2) waste products eg bilirubin, end products of haemoglobin destruction and excess of cholesterol are excreted in bile
