Definition of platelet
1. Concept of plateletPlatelets, or 'platelets', are small, irregular and lacking cytoplasmic fragments of core, 2-3 µm in diameter, 1 arising from the fragmentation of their precursor cells, megakaryocytes; the average life of a platelet is between 8 and 12 days. Platelets play a key role in hemostasis and are a natural source of growth factors. They circulate in the blood of all mammals and are involved in hemostasis, starting the formation of clots or thrombi.
If the number of platelets is too low, can cause excessive bleeding. On the other hand if the number of platelets is too high, they can form clots and cause thrombosis, which can clog the blood vessels and result in an accident causing brain vascular, acute myocardial infarction, pulmonary embolism and the blocking of blood vessels in any other part of the body, as in the upper and lower extremities; any abnormality or disease of the platelets is called trombocitopatia, 2 which can be, whether a reduced number of platelets (thrombocytopenia), a deficit in function (glanzmann), or an increase in the number of (thrombocytosis). There are disorders that can reduce the number of platelets, as thrombocytopenic purpura (ITP) idiopathic and cause bleeding problems, but on the other hand others such as heparin-induced thrombocytopenia may cause thrombosis, or clot, rather than bleeding.
Platelets release a large number of growth factors including growth factor derived from platelets (PDGF, by platelet derived growth factor), a potent chemotactic agent, and transforming growth factor beta (TGF-beta, by transforming growth factor) which stimulates the deposit of extracellular matrix; These two growth factors have been shown to play a significant role in the regeneration and repair of connective tissue; Other growth factors produced by platelets and associated with healing processes include: basic growth factor of fibroblast (basic fibroblast growth factor), factor of growth-1 associated with insulin (English IGF-1 insulin-like growth factor-1), factor of growth of the epithelium (epithelial growth factor English EGF), (English hepatocyte growth factor HGF) hepatocyte growth factor and growth factor of vascular endothelium (the English vascular endothelial growth factor VEGF). The local application of these growth factors in high concentrations through the platelet-rich plasma (PRP English platelet-rich plasma) has been used for several decades, to accelerate the healing process of different injuries.
2. Definition of plateletThe word platelet in its sense of small dimension plate, usually used in different fields as for example when there is talk of platelet sound.
However, its use is more common in biology, where many corpuscles of disk format-appoints or oval, biconvex, found in the blood of the mammalian vertebrates, including humans. They are also known as thrombocytes. They do not possess core or hemoglobin, approximate diameter is of 3 μm and are surrounded by a single membrane. Its function is the intervene in the process of coagulation, therefore when you have few platelets are more prone to suffer from bleeding. There may be platelet failure in some diseases such as leukemia. Platelets accumulate before the bleeding (coalesce) to interrupt it, by dabbing the blood flowing, forming a thrombus. While the coagulation occurs when blood is at a standstill.
However it is also positive to own too many platelets as an excessive clotting can cause thrombosis. They also intervene like growth factor. Per each cubic millimeter of human blood, there are approximately between two hundred and three hundred thousand platelets.
There are barely more than one week, and are formed from cytoplasmic division of megakaryocytes, which are large bone marrow cells.
Platelets are viewed with a light microscope, but to avoid that they bring together and can be studied, be mixed with a liquid anticoagulant. Thus, under the influence of a stain of blood, platelets are recognized two elements: a clear substance which takes to the coloring of a bluish tone, which is called hialomera and another in the center that takes on a more intense color, blue or red, and that is called granulomero, because perceived formed by a kind of granules.
3 Meaning of plateletPlatelet is a concept derived from plate. One of its most common uses is in the field of biology and refers to a kind of cell that is found in vertebrates and which is very important for blood coagulation.
These cells, irregularly, lack nucleus and live between eight and twelve days. Platelets are found in the bloodstream and are key in the development of clots that help stop bleeding. Each platelet, therefore intervenes in the process known as haemostasis, which does not leave blood vessels that allow their circulation.
This means that if the number of platelets in a body is reduced, possible hemorrhages are profuse. At the other end, a high number of platelets leads to a tendency to the formation of thrombus and clots, capable of generating blockages in the vessels and cause serious disorders of health (such as a stroke, a heart attack or a stroke).
Platelets are produced in the bone marrow through the Thrombopoiesis. There is a hormone called thrombopoietin, which regulates this production. Once they are in the blood, platelets are stored in the spleen though they are also destroyed by this same body and present in the liver cells.
Another meaning of the notion of platelet refers to a rectangular element that can be used as a covering or to transmit information through any registration. For example: "the singer received a plaque for 100,000 albums sold throughout his career".