White blood cells

 

White blood cells or leukocytes are cells of the immune system involved in defending the body against both infectious disease and foreign materials. They are produced and derived from multipotent cells in the bone marrow known as a hematopoteic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. There are a variety of types of white blood cells that serve specific roles in the human immune system. WBCs constitute approximately 1% of the blood volume.

The normal range (99% of pollution analyzed) for platelets is 150,000 to 450,000 cubic millimeter. If the number of platelets is too low, excessive bleeding can occur, However, if the number of platelets is too high, blood clots can form thrombosis, which may obstruct blood vessels and result in such event as a stroke, myocardial infarction, pulmonary embolism, or blockage of blood v

Vessels to other parts of the body, such as the extremities of the arms or legs. An abnormality or disease of the platelets is called thrombocytopathy, which can be a low number of platelets (thrombocytopenia), a decrease in function of platelets (thrombasthenia), or an increase in the number of platelets (thrombocytosis). There are disorders that reduce the number of platelets, such as heparin-induced thrombocytopenia (HIT) or thrombotic thrombocytopenia purpura (TTP), that typically cause thrombosis, or clots, instead of bleeding.

Platelets release a multitude of growth factors including platelet-derived growth factor (PDGF), a potent chemotactic agent, and TGF beta, which stimulates the deposition of extracellular matrix. Both of this growth factor has been shown to play a significant role in the repair and regeneration of connective tissues. Other healing—associated growth factors produced by platelets include basic fibroblast growth factor, insulin-like growth factor1, platelet-derived epidermal growth factor, and vascular endothelial growth factor. Local application of this factor in increased concentrations through platelet-rich plasma (PRP) has been as an adjunct to wound healing for several decades.