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33 Cards in this Set
- Front
- Back
List the major functions of the liver
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1. carbohydrate, lipid, amino acid metabolism
2. protein synthesis 3. storage 4. secretion and synthesis of bile salts 5. excretion and detoxification |
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Name the two main cell types of the liver. Which performs most of the functions of the liver
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Hepatocytes and Kupffer cells. Hepatocyte perform most functions.
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In the fed state, what does the liver do with excess glucose?
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Stored as glycogen or converted to fats, or with amino acids is used to make new amino acids (transamination)
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How does the liver supply the blood with glucose in the fasting state?
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Glycogenolysis- breaks down glycogen
Glycogenesis: makes new glucose from non-carbohydrate sources (e.g. amino acids and glycerol from triglycerides). |
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List the hexoses to which the liver converts glucose, and from which glucose can be produced.
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fructose and galactose
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name the pathway used to produce pentoses from glucose
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pentose-phosphate pathway
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What is the name of the process that involves a reversal of the glycolytic pathway?
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Gluconeogenesis
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What substances can be converted into fatty acids by the liver
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Glucose, fructose, and some amino acids
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How can the liver use fats as an energy source
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fatty acids can undergo beta oxidation to produce acetyl-CoA wich is the starting material for Kerbs
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Name three substances which can be produced by acetyl CoA.
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ketone bodies, fatty acids, cholesterol.
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Name the enzyme which regulates cholesterol biosynthesis
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3-HMG-CoA reductase
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List the possible fate of an amino acid which finds itself in the liver
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Transaminationto produce new amino acids from carboxylic acids, deamination to produce new oxycarboxylic acids, catabolised for energy production, incorporated into new proteins, returned to the blood stream
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How is excess nitrogen, produced from deamination of amino acids, removed safely from the body?
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Nitrogen in the form of ammonia liberated from amino acids is converted to urea in the liver.Urea is not as toxic as ammonia and is water soluble. SO it can be transported in the blood and excreted by the kidneys, skin and lungs.
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Name the two categories of protein synthesized in the liver
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Proteins to be used in the liver
Plasma proteins |
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How is excess protein stored in the liver?
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excess protein is stored by increasing the number of protein cells (hyperplasia), or by increasing the size of the liver cells (hypertrophy)
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What is the main cause of coma in people with liver failure?
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cannot produce urea in the liver and so ammonia increases and is toxic to the CNS (thus, coma)
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How does protein metabolism in the liver relate to the neurological abnormalities associated with advanced liver disease?
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.
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List three symptoms resulting from increases in bilirubin levels in the blood
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Jaundice, pale stools, dark urine
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List four substances stored in the liver
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glycogen
proteins vitamins ADEK & B12 Iron |
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Name the main secretion of the liver
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Bile
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List the main components of bile
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water, bile salts, glucosaminoglycans, bile pigments, cholesterol, phospholipids, electrolytes
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what is the function of bicarbonate in bile?
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Bicarbonate neutralizes gastric acid
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Name two substances which are conjugated to cholic acid to form bile salts
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taurine
glycine |
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what are the two main categories of reaction in the detoxification process?
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Phase I and Phase II
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name the enzyme system largely responsible for the initial phase of detoxification and the generic name for the enzymes involved
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MOS (mixed oxidase system)
cytochrome P450 |
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List three substances which become more toxic after they have been phagocytosed by Kupffer cells
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Silica, methylcellulose and lipopolysacchardies produced from gram negative bacteria
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List five processes performed by the liver, not performed elsewhere in the body
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activation of vit D, metabolism of tryptophan to nicotinic acid, detox and elimination of chemicals, glycogen storage, bile production, urea synthesis, production of clotting factors
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where does most of the livers blood supply come from?
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digestive system via the portal vein
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what is the end product of b-oxidation of fatty acids?
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acetyl CoA
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what condition does an excess of ketone bodies cause?
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metabolic acidosis
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what is the main function of the kupffer cells?
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phagocytosis
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why is treating the liver a good idea in people with dysglycaemia?
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Dysglycaemia= dysfunctional control of blood glucose levels.Liver controls BGL via gluconeogenesis, glycogenesis, glycogenesis, thus diseased liver will not control BGL well.
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why are bleeding disorders common in liver dysfunction?
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because liver dysfunction results in blood clotting factors not being made, bile not being secreted, and so fat soluble substances like vit K cannot be absorbed.
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