1. NECESSITY FOR BLOOD CLOTTING SEALS A WOUND PREVENT EXCESSIVE BLOOD LOSS FROM THE BODY PREVENTS THE ENTRY OF MICROORGANISMS AND FOREIGN PARTICLES INTO THE BODY THROUGH THE WOUND PREVENTS BLOOD PRESSURE FROM FALLING TO A LOW LEVEL AS PRESSURE IS NEEDED

2. MECHANISM OF BLOOD CLOTTING INJURY/RUPTURE IN BLOOD VESSELS (accidentally cut the finger and bleedings) PLATELETS CLUMP AT THE WOUND (platelets in the blood become sticky and clump together to plug the wound, so it can reduce blood loss) release THROMBOKINASE (clotting factor VIII) converts PROTHROMBIN (in the liver) THROMBIN (active enzyme) Vitamin K converts Calcium ions Fibrinogen ( soluble plasma protein) Fibrin ( insoluble fibres) a meshwork of threads over the wound Trap erythrocytes & platelets Blood Clotting forms Scab falls off, form new skin

3. CONSEQUENCES OF AN IMPAIRED BLOOD CLOTTING MECHANISM DISEASE CAUSES BY HOW TO OVERCOME/ PREVENT/REDUCE HAEMOPHILIA lack of gene for production of clotting factor (factor VIII) an impaired clotting mechanism which causes serious bleeding haemophiliacs may die of internal or external bleeding. factor VIII can now be produced by generic engineering THROMBOSIS a local blood clot (thrombus) is formed on the damaged rough inner wall of the artery. blockage of the artery. Thrombus dislodge and is carried away by blood circulation(embolus) embolus trapped & block the blood flow. EMBOLISM HEART ATTACK the coronary artery is partially blocked. cuts off the supply of oxygen and nutrients to the heart muscle. extensive heart muscle damage can cause death. avoid to take foods rich in fats consume more fruits and vegetables exercise and practise a healthy lifestyle