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Download IB 3 Liver - susanpittinaro
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The Liver Anatomy Largest gland in the body (1.5 kg) Under the diaphragm, within the rib cage in the upper right quadrant of the abdomen Only human organ that can selfregenerate Anatomy 4 lobes Major: left & right Minor: caudate & quadrate Ducts Common hepatic Cystic From gallbladder Common bile Joins pancreatic duct at hepatopancreatic ampulla Anatomy Blood flow Hepatic artery Brings oxygenated blood to liver Hepatic vein Carries deoxygenated blood away from the liver Hepatic Brings portal vein blood from small intestine Deoxygenated but full of nutrients Blood flow Hepatic portal vein divides into smaller vessels called sinusoids Sinusoids eventually drain into the central vein of the lobule Eventually drains into the hepatic vein Hepatic vein drains into the inferior vena cava Bile production Hepatocytes (liver cells) secrete bile Bile is secreted into the canaliculi To the bile ductules To the common bile duct To the gall bladder Storage To the bile duct To the small intestine Helps digest fats Gallbladder anatomy Thin-walled green muscular sac On the inferior surface of the liver Stores bile that is not immediately needed for digestion When muscular wall of gallbladder contracts, bile is expelled into the bile duct Functions The liver has more than 200 functions, including: Regulation of blood glucose & glycogen Storage of nutrients Including iron, vitamin A, & vitamin D Breakdown of erythrocytes Bile secretion Synthesis of plasma proteins Incl globulins, albumin, prothrombin, & fibrinogen Synthesis of cholesterol Detoxification of harmful substances Functions Normal blood glucose = 90 mg/100 mL Liver pulls excess glucose from blood plasma and stores it as glycogen As blood sugar levels decrease, glycogen reserves are converted back to glucose Functions Adjusts amino acid levels in blood Excess amino acids are deaminated and excreted through the kidney Functions What gets broken down? Insulin & other hormones Hemoglobin Toxic substances Alcohol & drugs Some antibiotics & hormones Including estrogen & testosterone Converts ammonia to urea Waste products are excreted through the kidneys Erythrocyte breakdown Red blood cells have a life span of 120 days RBCs weaken and rupture, releasing hemoglobin into the blood plasma Erythrocyte breakdown Hemoglobin is absorbed by phagocytosis by Kuppfer cells in the liver Hemoglobin is split into: Heme groups Iron is removed from heme Iron is carried to bone marrow Used for hemoglobin in new RBCs Remaining substance = bilirubin Becomes bile pigment Globins Hydrolyzed into amino acids and returned to blood Erythrocyte breakdown Problems with excessive alcohol consumption Metabolized alcohol may still be toxic to cells Healthy liver cells are replaced with fibrous scar tissue Reduces ability to metabolize carbohydrates, fats, & proteins Reduces ability to transport materials through the body Blood flow is blocked to and from the liver Over time, this may lead to nutritional deprivation & increased susceptibility to infection Problems with excessive alcohol consumption Long term alcohol abuse results in 3 primary effects on the liver: – swelling of damaged liver tissue Fat accumulation Cirrhosis – build up scar tissue left in areas of liver destroyed by prolonged alcohol exposure Inflammation Any questions?
