Circulatory System

             Platelets are flattened discs that are round from above and spindle shaped section. Megakaryocytes are very active cells that continually make proteins, enzymes, and membranes. But instead of getting bigger. They just shed small membrane-enclosed packets of cytoplasm into circulation. This is where platelets come from. Platelets were once thought to had lost their nucleus so histologists called them thrombocytes. They are constantly getting replaced. A platelet circulates for about 10 - 12 days and are removed by phagocytes. Platelets help in a vascular clotting system, which also has plasma proteins and the cells and tissues of the circulatory network. Homostasis prevents the loss of blood throughout damaged vessels. In this it stops blood lose and makes framework for the tissue repair.
             Other Functions of platelets include: Transport of chemicals important to the clotting process, Formation of temporary patch in walls of damaged blood vessels, And active contractions after clot formation have taken place.
             2. Blood Clots have 3 phases of formation:
             ] Thromboplastin triggers clotting by converting prothrombin into thrombin. Some thrombin is released when platelets disintegrate at the site of vascular injury. The injured tissue releases additional thromboplastin, especially vascular walls, with the calcium ions.
             ] In this stage prothrombin is converted into thrombin by both intensive and extensive thromboplastin and several plasma coagulating factors.
             ] In this stage fibrinogen is converted to fibrin, by thrombin formed in stage 2. More plasma factors are also involved. The insoluble fibrin forms a meshwork of fine protein threads that traps erythrocytes. Since red blood cells don't have anything to do with the chemical activities involved, clotting will occur in plasma even when the blood cells have been lost. The formation of a blood clot normally occurs in about five to eight minutes. A little while after starting the clot...

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Circulatory System. (1969, December 31). In MegaEssays.com. Retrieved 15:18, March 28, 2024, from https://www.megaessays.com/viewpaper/71643.html