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Cardiac Pharmacology: Difference between revisions
→Platelet/Clotting System
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==Platelet/Clotting System== | ==Platelet/Clotting System== | ||
[[File:Platelet_receptors.svg|thumb|Platelet activation and inhibition operates through surface receptors on platelets. Feedback loops enhance platelet activation (e.g. ADP released by platelets increases platelet activation, through the ADP receptor)]] | [[File:Platelet_receptors.svg|thumb|300px|Platelet activation and inhibition operates through surface receptors on platelets. Feedback loops enhance platelet activation (e.g. ADP released by platelets increases platelet activation, through the ADP receptor)]] | ||
Platelets (also known as thrombocytes) are small cells lacking nuclei that are responsible for haemostasis, or blood clotting. Damage or injury leading to blood loss and exposure of extracellular collagen fibres is detected, activating platelets. Once activated, platelets become adhesive, sticking to both the damaged vessel wall and each other, forming a clump of cells, or ‘clot’, helping to dam the vessel leak. They then begin to secrete cytokines that encourage invasion of fibroblasts present in the surrounding tissue which form a more permanent patch, either by creating healthy tissue, or depositing extracellular matrix to form a scar. | Platelets (also known as thrombocytes) are small cells lacking nuclei that are responsible for haemostasis, or blood clotting. Damage or injury leading to blood loss and exposure of extracellular collagen fibres is detected, activating platelets. Once activated, platelets become adhesive, sticking to both the damaged vessel wall and each other, forming a clump of cells, or ‘clot’, helping to dam the vessel leak. They then begin to secrete cytokines that encourage invasion of fibroblasts present in the surrounding tissue which form a more permanent patch, either by creating healthy tissue, or depositing extracellular matrix to form a scar. | ||