Flashcards in Option D.3 Function of the Liver Deck (52)
Give an example of how the liver regulates nutrients in blood
- liver maintains correct amount of glucose
when glucose level is high, liver releases insulin;
to stimulate hepatocytes to take up glucose;
to convert to glycogen;
when glucose level low, hepatocytes are stimulated;
to break down stored glycogen;
to release glucose
What occurs when transferring receptors are bound?
receptor iron complex enter cell and iron is either incorporated into heme/ or transferred to a storage molecule called ferritin
What do developing red blood cell have high levels of?
What is transferrin?
protein bound to iron
What happens iron is absorbed by small intestine?
tranferred to blood bound to a protein
Where is hemoglobin synthesized in?
red blood cells
When are iron/vitamin A/ vitamin D released into blood when stored in lover?
deficit in blood
What nutrients can be stored in excess in the liver?
glucose, when high causes insulin to stimulate hepatocytes to take up glucose and store as glycogen;
iron; Vitamin A; Vitamin D; vitamins are fat soluble
What happens to excess amino acids?
deaminated in the liver; organic acid part is removed/respired or converted to fat/carbohydrate
can the body store amino acids if in excess?
When proteins are broken down what do they contribute to?
pool of amino acids in blood plasma for new synthesis
What are examples of proteins that are produced for export from liver cells?
fibrinogen, globulins, albumin, prothrombin
What is the effect of having the liver adjust level of amino acids?
regulated to support the constant synthesis of proteins that can function as enzymes/components of membranes /structural components
What does the liver cell adjust as blood passes the sinusoids (supplies daily demand for protein)?
What happens to components of red blood cells by liver?
broke down when old and recycled
What is bile used for?
break down fats into droplets that disperse for effective breakdown by digestive enzymes in duodenum
What is surplus cholesterol from the liver converted into?
bile salts (emulsifies the bile)
What does the liver produce other than bile?
Explain the role of liver in hemoglobin breakdown
Kupffer cells take up erythrocytes through phagocytosis;
hemoglobin is broken into globin and heme;
globin is hydrolysed;
breakdown of heme causes iron to attach to carrier protein;
iron stored or exported to bone marrow (via blood plasma) for new red blood cell;
heme converted into bile pigments
What are erythrocytes?
red blood cells
What are Kupffer cells?
phagocytes attached to walls of sinusoids that take up old red blood cells; contain many lysosome; specialized leucocyte
What are lovules?
rows of hepatocytes
Give an example of how the liver removes toxins
alcohol is oxidized to become carboxylic acid; becomes part of metabolites; oxidized to CO2 and water
What are bile channels?
bile from liver flows through (between liver cell rows but isolated from blood supply); merge into bile ducts to carry to gall bladder
What is one of the major functions of the liver?
break down of red blood cells;
Wstabilization of quantity of nutrients circulating blood; regulation through storage and release of nutrients when needed
How does the blood from the heptic portal vein differ from normal blood?
- are wider
- is low pressure , deoxygenated blood
- varies in quantity of nutrients depending on food and timing
- contain kuppfer cells (brekadown haemoglobin for recycling)
After arterioles join with sunsoids what occurs?
Sinusoids merge with velues that lead to hepatic vein
How do sinuiods differ from liver cells?
sinuids do not have walls separating blood from liver cells (blood and liver cells are in direct contact); allows proteins to enter /leave blood
What are hepatocytes?