The Liver and Jaundice

Anatomy Left and right lobes, falciform ligament   <IMG class=c alt="이미지를 클릭하면 원본을 보실 수 있습니다." src="https://t1.daumcdn.net/cafefile/pds45/5_cafe_2007_07_31_08_21_46ae726286ce7" border=0> Anatomy Left and right lobes, falciform ligament Functional units are lobules Hepatocytes around central vein Sinusoids with Kupffer’s cells Hepatic portal vein Hepatic artery Bile ducts Portal triad   <IMG class=c alt="이미지를 클릭하면 원본을 보실 수 있습니다." src="https://t1.daumcdn.net/cafefile/pds42/8_cafe_2007_07_31_08_22_46ae72a69201f" border=0> <IMG class=c alt="이미지를 클릭하면 원본을 보실 수 있습니다." src="https://t1.daumcdn.net/cafefile/pds42/11_cafe_2007_07_31_08_22_46ae72c4a09e3" border=0> Functions Metabolic      Carbohydrate      Protein      Fat Bile Bilirubin Drugs and hormones Others   Carbohydrate Especially important in maintaining normal blood glucose levels      Glycogenesis      Glycogenolysis      Gluconeogenesis Converts other sugars into glucose Lipogenesis   <IMG class=c height=369 alt="이미지를 클릭하면 원본을 보실 수 있습니다." src="https://t1.daumcdn.net/cafefile/pds40/4_cafe_2007_07_31_08_24_46ae73159f859" width=626 border=0> Protein Deaminates amino acids Converts ammonia to urea Synthesizes most plasma proteins Transaminates amino acids to others   <IMG class=c alt="이미지를 클릭하면 원본을 보실 수 있습니다." src="https://t1.daumcdn.net/cafefile/pds41/8_cafe_2007_07_31_08_25_46ae735380b47" border=0> Lipid Stores triglycerides Breaks down fatty acids to acetyl CoA (b oxidation) Converts excess acetyl CoA to ketone bodies (ketogenesis) Synthesizes lipoproteins Synthesizes cholesterol   <IMG class=c style="WIDTH: 525px; HEIGHT: 374px" height=374 alt="이미지를 클릭하면 원본을 보실 수 있습니다." src="https://t1.daumcdn.net/cafefile/pds43/5_cafe_2007_07_31_08_25_46ae737a4ce2f" width=440 border=0> Bile production Essential for digestion of fats 600 - 1200 ml per day 0.6 g bile salts daily      Digestion      Micelles      Reabsorbed Enterohepatic circulation   Bilirubin Hemoglobin broken down to biliverdin Rapidly converted to free bilirubin transported attached to albumin Conjugated bilirubin Urobilinogen 0.1 - 1.2 mg/dl (normal total serum)   <IMG class=c alt="이미지를 클릭하면 원본을 보실 수 있습니다." src="https://t1.daumcdn.net/cafefile/pds40/6_cafe_2007_07_31_08_26_46ae73ba92319" border=0>   Drugs Smooth ER of liver cells Phase 1 reactions      Microsomal enzymes      Cytochrome P450 system      Activity can be induced, suppressed or inhibited      Glutathione pathway Phase 2 reactions      Lipid soluble converted to water soluble      Diet is critical   Drugs 1. phase 1 reaction: chemically modification. 2. locate in lipophilic membrane in smooth ER of liver cells. 3. gene codes of microsomal enzymes is cytochrome P450 system. 4. This identifies and trace to metabolism of specific drugs. 5. phase 2 reaction: lipid soluble conversion to water soluble 6. diet is critical. 7. glutathione pathway detoxifies compounds 8. it includes metabolizing paracetamol. 9. chronic alcohol ingestion decrease glutathione stores 10. it increase the risk for paracetamol toxicity. Hormones Insulin and glucagon Thyroxine Steroid hormones   Others Storage      Glycogen      Vitamins (A, B12, D, E and K)      Minerals (Fe and Cu) Phagocytosis Activation of vitamin D   Jaundice Apparent when bilirubin rises above 2 - 2.5 mg/dl Yellowish discolouration skin and deep tissue Elastic tissue of sclera usually first detected   Causes Excessive destruction of RBCs      Prehepatic Impaired uptake of bilirubin Reduced conjugation of bilirubin      Intrahepatic Obstruction of flow of bile      Posthepatic Prehepatic Haemolytic blood transfusion reaction Disease      Sickle cell anaemia      Thalassemia      Spherocytosis      Haemolytic disease of the newborn Neonatal hyperbilirubinemia   Prehepatic Mild jaundice Unconjugated bilirubin elevated Stools normal colour Urine negative for bilirubin   Intrahepatic Conjugation of bilirubin is impaired by:      Damaged hepatocytes      Transport into hepatocytes disrupted      Lack of required enzymes Hepatitis and cirrhosis most common causes Drugs      Halothane, oral contraceptives, estrogen, anabolic steroids,      isoniazid, chlorpromazine   Intrahepatic Conjugated and uncongugated bilirubin elevated Urine often dark Alkaline phosphatse slightly elevated   Posthepatic Cholestatic jaundice Bile flow obstructed between liver and intestine Strictures of bile duct Gallstones Tumours of bile duct or pancreas     <IMG class=c style="WIDTH: 708px; HEIGHT: 474px" height=653 alt="이미지를 클릭하면 원본을 보실 수 있습니다." src="https://t1.daumcdn.net/cafefile/pds45/11_cafe_2007_07_31_08_30_46ae74758fcf2" width=1023 border=0> Posthepatic Conjugated bilirubin elevated Stools clay coloured Urine dark Alkaline phosphatase markedly elevated Pruritis often preceeds jaundice