Liver Physiology - Day 2

PHYSIOLOGY 1 2 3 4 The liver performs many complex and vitals functions that the technician must know in order to understand the pathological process that occur when this important organ is damaged. 5 6 The liver functions include: Endocrine Cl...

PHYSIOLOGY 1 2 3 4 The liver performs many complex and vitals functions that the technician must know in order to understand the pathological process that occur when this important organ is damaged. 5 6 The liver functions include: Endocrine Clotting factor Production of albumin Metabolism Exocrine Detoxification Reticuloendothelial 7 The endocrine function of the liver include the break down of hormones to avoid the abnormal accumulation in the body, like estrogens, that is the reason that explain why in men with chronic hepatocellular disease they develop gynecomastia, and changes in the body hair pattern. Also the liver contributes to the activation of vitamin D, which helps the body to absorb calcium 8 The clotting function of the liver included production of many of the clothing factors (prothrombin and fibrinogen), additionally through the bile salts that liver produce, the absorption of vitamin K from the intestines, which is an essential in the production of the clothing factors. 9 The liver produce plasmatic proteins like albumin, lipoproteins and other proteins that helps in transportation of different components in blood, and contribute to the blood viscosity. Albumins also help to maintain water balance in the body and contribute to osmotic pressure. 10 The exocrine function of the liver consists in produce and secretes bile, necessary for digestion and fats absorption. Secretes into the bile a solution rich in bicarbonate, which aids to diminish the acid in the duodenum. The excretion of bilirubin, a yellow pigment is an important function of the liver. The red blood cells last for about 120 days at which time they are destroyed by the spleen. Hemoglobin is broken down into bilirubin, and then excreted by the liver into the intestines with the bile, where it is finally eliminated from the body. 11 oIn hematologic diseases associated with abrupt breakdown of large number of red blood cells, the liver may receive more bilirubin than it can detoxify. The level of indirect or unconjugated bilirubin is elevated oIn biliary obstruction,or hepatocellular disease the hepatocytes pick up bilirubin and conjugate it, but can not dispose of it. The conjugated bilirubin is regurgitated into the blood stream, with resultant elevation of the conjugated or direct bilirubin 12 The metabolic function included to converts glucose into glycogen to be storage in the liver: The liver removes excess glucose from the blood and stores the glucose as glycogen. In between mealtimes, hepatocytes break down the glycogen and release glucose back into the bloodstream for use by the body cells. If the body requires more glucose than what is stored as glycogen, then the liver will make glucose from other sources. 13 Produces urea from the excess ammonia produced during protein metabolism. The liver converts ammonia into urea to be excreted by the kidneys. (The ammonia is toxic to the body and cannot circulate into the blood). Also plays an important role in the cholesterol metabolism (converts plasma cholesterol into bile salts) 14 The patients with severe liver disease, may have a strong breath with fruity odor, because of ammonium accumulation. The concentration of ammonium in the blood may rise to toxic levels and cause brain dysfunction (including confusion, coordination disturbances, tremor and coma) 15 Detoxification function of the liver is vital. The liver is the primary organ involved in the detoxification of drugs and poisons. There are many substances, which are first modified by the liver before being excreted by the kidney. Other substances are modified by the liver and then excreted into the bile. The vast majorities of the medications administered orally or parenterally are breakdown and processed in the liver. 16 The reticulo-endothelial functions together with the spleen are hematopoiesis in the embryo, antibodies production, removal of old RBC and phagocytosis through the Kupffer cells, that’s way the spleen can be removed without affect our body functions; the liver takes over. 17 18  LIVER FUNCTION TESTS 1. Aspartate aminotransferase (AST) 2. Alanine aminotransferasa (ALT) 3. Lactic acid 4. Alkaline phosphatase 5. Bilirrubina 6. Prothrombin time 7. Albumin and globulins 19 oAspartate aminotransferase (AST): increases with hepatocellular and obstructive disease Cellular injury and cellular death cause this enzyme to increase. AST is found in the liver, heart, skeletal muscle, kidneys, brain, and red blood cells, and it is commonly measured clinically as a marker for liver health. 20 oAlanine aminotransferase (ALT): is more specific than AST for evaluating liver function. The ALT is increased in hepatitis, cirrhosis. Considered a very specific indicator of hepatocellular disease 21 oBilirubin:An excessive amount of red blood cell destruction, malfunction of liver cells or blockage of ducts are causes of a rise in serum bilirubin These disturbances cause a rise in serum bilirubin, which leaks into the tissues and give the skin a jaundice, or yellow coloration Bilirubin direct (conjugated): increases with obstruction and hepatocelular disease. Bilirubin indirect (unconjugated): Increases with hemolytic disease. 22 oAlkaline phosphatase: may be a good indicator of intra or extrahepatic obstruction, hepatic carcinoma and cirrhosis 23 oProthrombin time:prothrombin is a liver enzime that is part of the blood clotting mechanism. The production of prothrombin depends on adequate intake and use of vitamin K. Is increase in presence of cellular damage as cirrhosis and metastatic disease 24 oAlbumin and globins: chronic liver diseases commonly show an elevation of gamma globulins 25  Alfa Feto Protein (AFP) This fetal antigen is manufactured by the adult liver when the patient has a hepatocellular carcinoma or metastatic disease of the liver. 26 27  Which is NOT a function of the liver? a. Production of glucagon b. Detoxing the body of alcohol c. Metabolizes nutrients d. Bile production 28 TRUE OR FALSE. Alkaline phosphatase is not a good indicator of intra or extra hepatic obstruction. 29 Which serum marker increases with hemolytic disease in the liver? a.Alpha feta protein b.Blood glucose levels c.Bilirubin direct d.Bilirubin indirect 30  -Bilirubin direct (conjugated): Increases with obstruction and hepatocellular disease. -Bilirubin indirect (unconjugated): Increases with hemolytic 31