Ms Amanda Clements ANATOMY AND PHYSIOLOGY OF THE LIVER. Pre-Conference Nurse s Course. Plymouth Hospital NHS Foundation Trust 12/12/2014

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1 Pre-Conference Nurse s Course in partnership with Ms Amanda Clements Plymouth Hospital NHS Foundation Trust ANATOMY AND PHYSIOLOGY OF THE LIVER Amanda Clements Nurse Consultant Hepatology 1

2 Anatomy Largest solid organ (after skin) kg 2.5% body weight Under the rib cage Right upper quadrant of the abdomen embryology 4 th week development 12 th week liver begins to secrete bile late pregnancy liver 5% of weight 2

3 Anatomical variant Reidel lobe extension of right lobe liver Gross anatomy Divided by falciform ligament (remanant of embryonic umbilical vein) FL Attaches Liver to diaphragm and ant. abdo. wall Fibrous Glisson s Capsule 3

4 Anterior view 2 uneven lobes R biggest Rt lobe = quadrate & caudate lobe Inferior view 4

5 Liver Topography Segmental Anatomy (Couinaud System) Caudate Lobe Segment I Left Lobe Segments II IV Right Lobe Segments V-VIII 5

6 Liver Vasculature ¼ of resting cardiac output Liver dual blood supply Hepatic artery oxygenated blood Hepatic portal vein deoxygenated blood- nutrients, drugs, toxins etc from GI tract Portal Vein 75% hepatic blood flow, union superior mesenteric veins and splenic veins Drains venous blood from GI tract, spleen, pancreas, gallbladder 6

7 Hepatic Artery 25% hepatic blood flow 50% O 2 supply Hepatic arteries supply biliary epithelium Liver drainage 3 major veinsleft, middle, right hepatic veins Into inferior vena cava 7

8 Biliary drainage Gallbladder under R lobe Stores / concentrates bile Drained by cystic duct, joins common hepatic duct to form common bile duct Microscopic anatomy - lobule Functional units, Hexagonal structure Organised around central vein (tributary of HV) portal triad /tract = branches of HA, PV, BD - form corner of hexagon 8

9 Microscopic anatomy - acinus Liver parenchyma in zones Hepatocytes Zone 1 closes to portal triad = richest supply of O 2 & nutrients, more likely to be damaged by drugs / toxins Zone 3 nearer central vein poor O 2 = hypoxic damge 9

10 Sinusoids Spaces lines with endothelium, partly lined with stellate reticulo-endothelial Kuppfer cells Particle eating macrophages / phagocytes break down old red/ white blood cells, bacteria, foreign matter Hepatic lymph formed by drainage of perisinusoidal space of Disse drain into portal vessels Bile formation & excretion Bile = water, electrolytes, bile pigments, bile acids, cholesterol, phospholipids, albumin, immunoglobulins Lipid digestion & absorption, immunological defence, excretion of endogenous compounds, removal of xenobiotics mg produced a day Bile secreted by hepatocytes, flows into bile canniculi small bile ducts R&L hepatic ducts that unite, leave liver as CBD 10

11 Liver functions Carbohydrates Maintaining blood glucose break down of glycogen Glycogenolysis Gluconeogenesis converts AA & lactic acid to glucose Sugar conversion fructose / galactose glucose Glycogenesis converts glucose to glycogen = storage Lipogenesis break down of triglycerides 11

12 Lipids Ketogenesis break down of fatty acids Synthesis lipoproteins transport fatty acids, triglycerides and cholesterol to and from cells Hepatocytes synthesise cholesterol Cholesterol needed in bile production = important in emulsification and absorption of fats in small intestine Synthesis Clotting factors Carrier proteins Albumin 12

13 Protein Plasma proteins Hepatic structural components and internal enzymes Albumin major transport protein, important in the regulation of tissue fluid distribution Specialised transport proteins transferrin = iron, caeruloplasmin = copper, transcortin = steroid hormones Blood clotting proteins most of proteins for complement system - immunity Protein Protease inhibitors A1AT inflammatory activiy control Enzymes transamination AA conversion Enzymes deamination breakdown proteins energy production, CHO / Fat production Conversion of NH 3 - by product of protein metabolism water soluble urea urine excretion 13

14 Detoxification Metabolism Processing drugs / hormones Detoxification alcohol Excretion into bile penicillin, erythromycin, sulfonamides Cytochrome P450 mono-oxygenases (70+ enzymes) = fat soluble chemicals / toxins ( can penetrate lipid bilayer of cell membranes) = water soluble excretion in bile / urine: First Pass metobolism Chemically alters / excretes thyroid / steroid hormones = sex hormones / aldosterone 14

15 Excretion Bilirubin derived from the heam molecule of broken down RBCs Absorbed by the liver from the blood Majority of bilirubin metabolised by bacteria in intestine, eliminated in faeces Storage Glycogen Fatty acids Vitamins Minerals 15

16 Storage Glygogen, vitamins ADEK (Fat soluble) B 12 Minerals Fe, Cu Hepatocytes contain apoferritn combines with Fe to form ferritin form of Fe stored in liver Iron stores released and mobilised around body when needed Others Immunity Role of Kuppfer cells to ingest and break down microbes & old blood cells Activation The skin, liver and kidneys participate in activatin vitamin D 16

17 What's the point? Understanding the normal anatomy and functions of the liver is essential for understanding abnormal LFTs and your patients liver disease symptoms 17