2.64B: Understand How Platelets are Involved in Blood Clotting, which Prevents Blood Loss and the Entry of Micro-Organisms

PLATELETS: Cell fragments involved in blood clotting

PLATELETS AND BLOOD CLOTTING

Diagram showing Role of Platelets in Blood Clotting

PROCESS: When Skin is wounded, clotting factors are released by damaged cells and platelets Clotting factors cause platelets to become sticky and adhere to damaged region to form a solid 'plug', also stimulating local vasoconstriction to reduce blood flow through damaged region Additionally, clotting factors trigger conversion of inactive Prothrombin to activated enzyme Thrombin which catalyses the conversion fo soluble Fibrinogen into insoluble fibrous form called Fibrin Fibrin forms mesh around wound and traps blood cells to form temporary clot, forming a scab to protect and allow wound to heal

FUNCTIONS: Clotting prevents the excessive blood loss from body Clotting prevents the entry of harmful Pathogens into bloodstream via wound