2Assessment Statements H Outline the circulation of blood through liver tissue, including the hepatic artery, hepatic portal vein, sinusoids and hepatic vein.H Explain the role of the liver in regulating levels of nutrients in the blood.H Outline the role of the liver in the storage of nutrients, including carbohydrate, iron, vitamin A and vitamin D.H State that the liver synthesizes plasma proteins and cholesterol.H State that the liver has a role in detoxification.H Describe the process of erythrocyte and hemoglobin breakdown in the liver, including phagocytosis, digestion of globin and bile pigment formation.H Explain the liver damage caused by excessive alcohol consumption.
3The circulation of blood through liver tissue the liver is a large, lobed organ located immediately below the diaphragm, and above and around the stomachliver is supplied with blood by the hepatic artery & hepatic portal veinhepatic artery delivers oxygenated blood from the hearthepatic portal vein brings deoxygenated blood to the liver from the small intestine which also contains nutrientsliver is drained by the hepatic vein which carries blood back to the heart
5Circulation of blood through liver tissue hepatic artery carries oxygenated blood to the liverhepatic portal vein carries deoxygenated blood to the liver from blood from the gut (small intestine)blood from hepatic portal vein and hepatic artery mix & flows through sinusoids (i.e. blood-filled channels), past lines of liver cellsfrom the sinusoid, the blood then flow on to a branch of the hepatic veinhepatic vein carries blood away from liver to the heart
6The roles of the liverThe liver performs more than 500 functions, which includes:regulation of nutrient levels in the blood;site of syntheses of plasma proteins & cholesterol;detoxification of poisons;breakdown of hemoglobin;storage of nutrients;production of bile pigments
7Role of the liver in regulating levels of nutrients in the blood
8Role of the liver in the storage of nutrients liver stores excess glucose as glycogen, it releases glucose from glycogen as levels dropliver breaks down red blood cells (haemoglobin) and stores ironliver stores fat soluble vitamins such as vitamin A, vitamin D, vitamin E, vitamin K & vitamin B12 (folic acid)stored nutrients are released from the liver when needed elsewhere in the body
9Role of liver in synthesis of plasma proteins & cholesterol liver is the site of synthesis of all the blood proteins, including globulins, albumin, prothrombin & fibrinogenmost of the cholesterol required by the body on a daily basis is manufactured in the liver, the remainder is taken in as part of the dietcholesterol synthesized in the liver has a variety of functions including being a component of cell membranes
10Role of liver in detoxification liver detoxifies harmful substances such as: alcohol, drugs & toxins that have entered the blood stream by breaking them into harmless forms for excretiondrugs such as the antibiotics penicillin & erythromycin and sulphonamides are also broken down into harmless wastes which are then excretedhormones such as thyroid hormone, and steroid hormones such as oestrogen, testosterone, & aldosterone are similarly inactivated, ready for removal from the blood through the kidney
12Process of erythrocyte & hemoglobin breakdown in the liver
13Process of erythrocyte & hemoglobin break down in the liver erythrocytes (red blood cells) have a life span of about 120 days after which they ruptureworn-out red blood cells are destroyed by Kupffer cells through phagocytosis in the reticular endothelial systemhemoglobin is split into haem groups and globins proteinsglobins proteins are hydrolyzed to amino acidsiron is removed from haem & stored in the liver or spleenhaem is converted to bilirubin (bile pigments)bilirubin (bile pigment) transferred to bileamino acid are deaminated into ammonia & hydrocarbonammonia is converted to urea while the hydrocarbon (carbohydrate) is respired
14Liver damage caused by excessive alcohol consumption fatty liver causes cirrhosis (inflammation of the liver) from alcohol abusei.e. usually from prolonged & excessive drinking of alcoholproducts of alcohol metabolism are toxic to cells as alcohol consumption reduces antioxidant activityleads to replacement of healthy liver cells with fibrous scar tissuethis blocks blood flow through liver , thus loss of functional liver cells,blocks normal metabolism of carbohydrates, fats & proteinsmay lead to decreased ability to remove toxins (through bile) & production of bile and blood proteinsnutritional deprivation / susceptible to infection/hepatic viruses;
15Outline the circulation of blood through liver tissue.  Explain the liver damage caused by excessive alcohol consumption.