Term
| What are the lobes of the liver? What is the basic functional unit of the liver? How many are there? |
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Definition
1. right, left, caudate, and quadrate
2. a lobule
3. 50,000-100,000 |
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Term
| How much resting blood flow does the liver receive? What is the resistance like? |
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Definition
1. about 27%
2. very low at about 9 mmHg in the portal vein and 0 mmHg in the hepatic vein |
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Term
| What are the cell types in the liver and what are their percentages? |
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Definition
| hepatocytes (60%), mesenchymal (35%), and bile ductal epithelia (5%) |
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Term
| What is cirrhosis? What causes it? |
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Definition
1. impeded blood flow to the liver, often due to the build-up of fibrous tissue around blood vessels leading to hepatocytes that have been destroyed
2. alcoholism, fat accumulation with inflammation (nonalcoholic steatohepatatis, poisons (such as carbon tetrachloride), viral hepatitis, obstruction of the bile ducts, and infectious processes in the bile ducts |
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Term
| Where do portal veins drain to? Where do hepatic arteries feed? What does the central vein drain from? |
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Definition
1. the hepatic sinusoids
2. the hepatic sinusoids
3. the hepatic sinusoids |
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Term
| How does the liver function as a reservoir for blood? |
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Definition
| 0.5 to 1 L of extra blood is store in the hepatic veins and sinuses in response to high pressure in the right atrium; the blood can be released when BP/BV drops |
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Term
| What is a less severe form of NASH? |
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Definition
| nonalcoholic fatty liver disease |
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Term
| What are conditions that can cause a rise in hepatial portal blood pressure but not necessarily systemic blood pressure? |
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Definition
| cirrhosis and a blood clot in the portal vein |
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Term
| What is the area of cells that feed bile into the bile canaliculi? What is the space around this called? What drains this space? |
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Definition
1. the liver cell plate
2. the space of Disse
3. lymphatic ducts |
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Term
| Where cells line the hepatic sinusoids? |
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Definition
| Kupffer cells and sinusoidal endothelial cells |
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Term
| What is significant about the hepatic lymph? |
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Definition
| because the hepatic sinusoids are so permeable and their pores are so large, the protein concentration of the hepatic lymph is almost the same as blood plasma |
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Term
| What happens if hepatic vascular pressure increases? |
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Definition
| more fluid will be drained into the space of Disse and eventually the lymphatics might not be able to keep up, causing fluid to leak into the abdominal cavity, causing ascites |
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Term
| What hormones stimulate liver regeneration? What hormones inhibit the regeneration? |
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Definition
1. hepatocyte growth factor, epidermal growth factor, tumor necrosis factor, and IL-6
2. transforming growth factor-β and possibly some other unknown factor |
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Term
| What is the function of the Kupffer cells? |
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Definition
| it digests bacteria in the blood, filtering 99%+ of the bacteria |
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Term
| What is the cholesterol synthesized in the liver used for? |
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Definition
| 80% is used for bile salts and the rest is stored in lipoproteins and shipped to cells |
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Term
| What are the functions of the liver in carbohydrate metabolism? |
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Definition
| it stores large amounts of glycogen for glucose buffering, converts galactose and fructose into glucose, provides gluconeogenesis, and can form other compounds from the products of carbohydrate metabolism (like in the pentose phosphate pathway) |
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Term
| What are the functions of the liver in fat metabolism? |
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Definition
| oxidation of FFAs to supply energy for other body functions; triglyceride storage; synthesis of cholesterol, phospholipids, and other lipoproteins; and synthesis of fat from protein and carbohydrates |
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Term
| What can cause additional TG storage in the liver? |
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Definition
| diabetes, starvation, and obesity |
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Term
| What are the functions of the liver in protein metabolism? |
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Definition
| deamination of amino acids, formation of urea for removal of ammonia from the body fluids, formation of plasma proteins (albumin, lipoproteins, etc), interconversions of various amino acids, and synthesis of other compounds from amino acids |
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Term
| What happens if plasma protein levels drop? |
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Definition
| the liver can replenish the protein, but liver mitosis is stimulate when the levels drop |
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Term
| What vitamins can be stored in the liver and how much? |
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Definition
1. a. vitamin A - approximately 10 months worth
b. vitamin B12 - 1+ years worth
c. vitamin D - 3-4 months worth |
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Term
| What is apoferritin? What is it used for? |
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Definition
1. it is a protein that combines reversibly with iron
2. it is used to store iron |
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Term
| How is the liver important to clotting? |
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Definition
| using vitamin K, the liver forms fibrinogen, prothrombin, accerlator globulin, and factors VII, IX, and X for clotting |
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Term
| How is the liver important in endocrine function? |
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Definition
| it can modify a lot of hormones, including essentially all the steroids (meaning it has a lot of cytochrome p450) as well as thyroxine and it can remove a lot of substances from the blood, including many exogenous drugs, calcium, etc |
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Term
| What is the mechanism of the liver's processing of hemoglobin? |
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Definition
| when the RBCs become fragile, they burst and the reticuloendothlial system (endothelial and Kupffer cells), uptake hemoglobin and split it into heme and globin; bilirubin is formed by the liver and is later absorbed into and converted into bilirubin glucoronide, bilirubin sulfate, and other forms and excreted into the bile; those forms are turned into urobilinogen by gut bacteria and can be further converted and excreted in the bile, can be absorbed into the plasma (as much of it is) and from there either be secreted back into the gut or filtered by the kidneys or converted into urobilin and excreted in the urine |
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Term
| What is jaundice? What are the types of jaundice? What are their differences? |
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Definition
1. a yellowish pigmentation of the skin due to bilirubin build-up
2-3. a. hemolytic - due to destruction of many RBCs; this causes rise in unconjugated bilirubin and urobilinogen in the blood
b. obstructive - due to bile duct obstruction or damage to the liver cells, causing an inability of the liver to dispose of the bilirubin; as more unconjugated bilirubin builds up, it is taken in the liver cells and conjugated but it can't be secreted into the intestines and turned into urobilinogen, so the blood levels of conjugated bilirubin rises |
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Term
| What tests can help to differentiate between hymolytic and obstructive jaundice? How can they help? |
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Definition
1-2. a. van den Berg test can differentiate between conjugated and unconjugated bilirubin in the plasma
b. in obstructive jaundice, stool will become clay colored due to a lack of stercobilin and other bile secretions
c. the kidneys can secrete conjugated bilirubin, but not the albumin-bound unconjugated form; shaking the urine and observing brightly colored yellow foam is indicative of conjugated bilirubin |
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Term
| What are ito cells? What are their function? |
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Definition
1. pericyte cells that exist in the space of Disse
2. they can store fat in the liver |
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