Platelets Information

7/30/2019 Platelets Information

1/15

Platelet

Image from alight microscope(40) from a peripheralblood smearsurrounded byred blood cells. One

normal platelet can be seen in the upper left side of the image (purple) and is significantly smaller in size

than thered blood cells(stained pink). Twogiant platelets(stained purple) are also visible.

Platelets, or thrombocytes(from Greek , "clot" and , "cell"), are small, disk shaped clear

cell fragments (i.e. cells that do not have a nucleus), 23 m in diameter,[1] which are derived from

fragmentation of precursormegakaryocytes. The average lifespan of a platelet is normally just 5 to 9

days. Platelets are a natural source ofgrowth factors. They circulate in thebloodofmammalsand are

involved inhemostasis, leading to the formation ofblood clots.

If the number of platelets is too low, excessivebleedingcan occur. However, if the number of platelets is

too high, blood clots can form (thrombosis), which may obstruct blood vessels and result in such events

as astroke,myocardial infarction,pulmonary embolismor the blockage of blood 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 a thrombocytopathy,[2] which could be either 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 thrombocytopenic purpura (TTP) that typically cause

thromboses, or clots, instead of bleeding.

Platelets release a multitude of growth factors includingplatelet-derived growth factor(PDGF), a potent

chemotacticagent, andTGF beta, which stimulates the deposition ofextracellular matrix. Both of these

growth factors have been shown to play a significant role in the repair and regeneration ofconnective

tissues. Other healing-associated growth factors produced by platelets include basic fibroblast growth
http://en.wikipedia.org/wiki/Light_microscopehttp://en.wikipedia.org/wiki/Light_microscopehttp://en.wikipedia.org/wiki/Light_microscopehttp://en.wikipedia.org/wiki/Blood_filmhttp://en.wikipedia.org/wiki/Blood_filmhttp://en.wikipedia.org/wiki/Blood_filmhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Giant_platelethttp://en.wikipedia.org/wiki/Giant_platelethttp://en.wikipedia.org/wiki/Giant_platelethttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Platelet#cite_note-1http://en.wikipedia.org/wiki/Platelet#cite_note-1http://en.wikipedia.org/wiki/Platelet#cite_note-1http://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Growth_factorshttp://en.wikipedia.org/wiki/Growth_factorshttp://en.wikipedia.org/wiki/Growth_factorshttp://en.wikipedia.org/wiki/Bloodhttp://en.wikipedia.org/wiki/Bloodhttp://en.wikipedia.org/wiki/Bloodhttp://en.wikipedia.org/wiki/Mammalhttp://en.wikipedia.org/wiki/Mammalhttp://en.wikipedia.org/wiki/Mammalhttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Thrombushttp://en.wikipedia.org/wiki/Thrombushttp://en.wikipedia.org/wiki/Thrombushttp://en.wikipedia.org/wiki/Hemorrhagehttp://en.wikipedia.org/wiki/Hemorrhagehttp://en.wikipedia.org/wiki/Hemorrhagehttp://en.wikipedia.org/wiki/Thrombosishttp://en.wikipedia.org/wiki/Thrombosishttp://en.wikipedia.org/wiki/Thrombosishttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Pulmonary_embolismhttp://en.wikipedia.org/wiki/Pulmonary_embolismhttp://en.wikipedia.org/wiki/Pulmonary_embolismhttp://en.wikipedia.org/wiki/Thrombocytopathyhttp://en.wikipedia.org/wiki/Thrombocytopathyhttp://en.wikipedia.org/wiki/Platelet#cite_note-2http://en.wikipedia.org/wiki/Platelet#cite_note-2http://en.wikipedia.org/wiki/Platelet#cite_note-2http://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombastheniahttp://en.wikipedia.org/wiki/Thrombastheniahttp://en.wikipedia.org/wiki/Thrombastheniahttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Chemotaxishttp://en.wikipedia.org/wiki/Chemotaxishttp://en.wikipedia.org/wiki/TGF_betahttp://en.wikipedia.org/wiki/TGF_betahttp://en.wikipedia.org/wiki/TGF_betahttp://en.wikipedia.org/wiki/Extracellular_matrixhttp://en.wikipedia.org/wiki/Extracellular_matrixhttp://en.wikipedia.org/wiki/Extracellular_matrixhttp://en.wikipedia.org/wiki/Connective_tissuehttp://en.wikipedia.org/wiki/Connective_tissuehttp://en.wikipedia.org/wiki/Connective_tissuehttp://en.wikipedia.org/wiki/Connective_tissuehttp://en.wikipedia.org/wiki/Fibroblast_growth_factorhttp://en.wikipedia.org/wiki/Fibroblast_growth_factorhttp://en.wikipedia.org/wiki/File:Giant_platelets.JPGhttp://en.wikipedia.org/wiki/Fibroblast_growth_factorhttp://en.wikipedia.org/wiki/Connective_tissuehttp://en.wikipedia.org/wiki/Connective_tissuehttp://en.wikipedia.org/wiki/Extracellular_matrixhttp://en.wikipedia.org/wiki/TGF_betahttp://en.wikipedia.org/wiki/Chemotaxishttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Thrombastheniahttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Platelet#cite_note-2http://en.wikipedia.org/wiki/Thrombocytopathyhttp://en.wikipedia.org/wiki/Pulmonary_embolismhttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Thrombosishttp://en.wikipedia.org/wiki/Hemorrhagehttp://en.wikipedia.org/wiki/Thrombushttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Mammalhttp://en.wikipedia.org/wiki/Bloodhttp://en.wikipedia.org/wiki/Growth_factorshttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Platelet#cite_note-1http://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Giant_platelethttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Blood_filmhttp://en.wikipedia.org/wiki/Light_microscope


2/15

factor, insulin-like growth factor 1, platelet-derivedepidermal growth factor, andvascular endothelial

growth factor. Local application of these factors in increased concentrations through Platelet-rich

plasma(PRP) has been used as an adjunct towound healingfor several decades.[3][4][5][6][7][8][9]

Kinetics

HSC=hematopoietic stem cell, Progenitor=progenitor cell, L-blast=lymphoblast,lymphocyte, Mo-

blast=monoblast,monocyte,myeloblast, Pro-M=promyelocyte,myelocyte, Meta-M=metamyelocyte,neutrophil,eosinophil,basophil, Pro-E=proerythroblast, Baso-E=basophilic erythroblast, poly-

E=polychromatic erythroblast, Ortho-E=Orthochromatic erythroblast,erythrocyte,promegakaryocyte,

megakaryocyte, platelet.

The physiological range for platelets is (150 400) 103 per mm3. Platelets are produced in blood cell formation (thrombopoiesis) inbone marrow, by budding off

frommegakaryocytes.

Megakaryocyte and platelet production is regulated by thrombopoietin, a hormone usuallyproduced by theliverandkidneys.

Eachmegakaryocyteproduces between 5,000 and 10,000 platelets. Around 1011 platelets are produced each day by an average healthy adult. Reserve platelets are stored in the spleen, and are released when needed by sympathetically

induced splenic contraction.
http://en.wikipedia.org/wiki/Fibroblast_growth_factorhttp://en.wikipedia.org/wiki/Fibroblast_growth_factorhttp://en.wikipedia.org/wiki/Insulin-like_growth_factor_1http://en.wikipedia.org/wiki/Insulin-like_growth_factor_1http://en.wikipedia.org/wiki/Insulin-like_growth_factor_1http://en.wikipedia.org/wiki/Epidermal_growth_factorhttp://en.wikipedia.org/wiki/Epidermal_growth_factorhttp://en.wikipedia.org/wiki/Epidermal_growth_factorhttp://en.wikipedia.org/wiki/Vascular_endothelial_growth_factorhttp://en.wikipedia.org/wiki/Vascular_endothelial_growth_factorhttp://en.wikipedia.org/wiki/Vascular_endothelial_growth_factorhttp://en.wikipedia.org/wiki/Vascular_endothelial_growth_factorhttp://en.wikipedia.org/wiki/Platelet-rich_plasmahttp://en.wikipedia.org/wiki/Platelet-rich_plasmahttp://en.wikipedia.org/wiki/Platelet-rich_plasmahttp://en.wikipedia.org/wiki/Wound_healinghttp://en.wikipedia.org/wiki/Wound_healinghttp://en.wikipedia.org/wiki/Wound_healinghttp://en.wikipedia.org/wiki/Platelet#cite_note-3http://en.wikipedia.org/wiki/Platelet#cite_note-3http://en.wikipedia.org/wiki/Platelet#cite_note-5http://en.wikipedia.org/wiki/Platelet#cite_note-7http://en.wikipedia.org/wiki/Platelet#cite_note-9http://en.wikipedia.org/wiki/Platelet#cite_note-9http://en.wikipedia.org/wiki/Hematopoietic_stem_cellhttp://en.wikipedia.org/wiki/Hematopoietic_stem_cellhttp://en.wikipedia.org/wiki/Progenitor_cellhttp://en.wikipedia.org/wiki/Progenitor_cellhttp://en.wikipedia.org/wiki/Progenitor_cellhttp://en.wikipedia.org/wiki/Lymphoblasthttp://en.wikipedia.org/wiki/Lymphoblasthttp://en.wikipedia.org/wiki/Lymphoblasthttp://en.wikipedia.org/wiki/Lymphocytehttp://en.wikipedia.org/wiki/Lymphocytehttp://en.wikipedia.org/wiki/Lymphocytehttp://en.wikipedia.org/wiki/Monoblasthttp://en.wikipedia.org/wiki/Monoblasthttp://en.wikipedia.org/wiki/Monoblasthttp://en.wikipedia.org/wiki/Monocytehttp://en.wikipedia.org/wiki/Monocytehttp://en.wikipedia.org/wiki/Monocytehttp://en.wikipedia.org/wiki/Myeloblasthttp://en.wikipedia.org/wiki/Myeloblasthttp://en.wikipedia.org/wiki/Myeloblasthttp://en.wikipedia.org/wiki/Promyelocytehttp://en.wikipedia.org/wiki/Promyelocytehttp://en.wikipedia.org/wiki/Promyelocytehttp://en.wikipedia.org/wiki/Myelocytehttp://en.wikipedia.org/wiki/Myelocytehttp://en.wikipedia.org/wiki/Myelocytehttp://en.wikipedia.org/wiki/Metamyelocytehttp://en.wikipedia.org/wiki/Metamyelocytehttp://en.wikipedia.org/wiki/Metamyelocytehttp://en.wikipedia.org/wiki/Neutrophilhttp://en.wikipedia.org/wiki/Neutrophilhttp://en.wikipedia.org/wiki/Eosinophilhttp://en.wikipedia.org/wiki/Eosinophilhttp://en.wikipedia.org/wiki/Eosinophilhttp://en.wikipedia.org/wiki/Basophilhttp://en.wikipedia.org/wiki/Basophilhttp://en.wikipedia.org/wiki/Basophilhttp://en.wikipedia.org/wiki/Proerythroblasthttp://en.wikipedia.org/wiki/Proerythroblasthttp://en.wikipedia.org/wiki/Proerythroblasthttp://en.wikipedia.org/w/index.php?title=Basophilic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Basophilic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Polychromatic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Polychromatic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Polychromatic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Orthochromatic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Orthochromatic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Orthochromatic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/wiki/Erythrocytehttp://en.wikipedia.org/wiki/Erythrocytehttp://en.wikipedia.org/wiki/Erythrocytehttp://en.wikipedia.org/wiki/Promegakaryocytehttp://en.wikipedia.org/wiki/Promegakaryocytehttp://en.wikipedia.org/wiki/Promegakaryocytehttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Thrombopoiesishttp://en.wikipedia.org/wiki/Thrombopoiesishttp://en.wikipedia.org/wiki/Thrombopoiesishttp://en.wikipedia.org/wiki/Bone_marrowhttp://en.wikipedia.org/wiki/Bone_marrowhttp://en.wikipedia.org/wiki/Bone_marrowhttp://en.wikipedia.org/wiki/Megakaryocyteshttp://en.wikipedia.org/wiki/Megakaryocyteshttp://en.wikipedia.org/wiki/Megakaryocyteshttp://en.wikipedia.org/wiki/Thrombopoietinhttp://en.wikipedia.org/wiki/Thrombopoietinhttp://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Kidneyhttp://en.wikipedia.org/wiki/Kidneyhttp://en.wikipedia.org/wiki/Kidneyhttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/File:Blood_cells_differentiation_chart.jpghttp://en.wikipedia.org/wiki/File:Blood_cells_differentiation_chart.jpghttp://en.wikipedia.org/wiki/File:Blood_cells_differentiation_chart.jpghttp://en.wikipedia.org/wiki/File:Blood_cells_differentiation_chart.jpghttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Kidneyhttp://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Thrombopoietinhttp://en.wikipedia.org/wiki/Megakaryocyteshttp://en.wikipedia.org/wiki/Bone_marrowhttp://en.wikipedia.org/wiki/Thrombopoiesishttp://en.wikipedia.org/wiki/Megakaryocytehttp://en.wikipedia.org/wiki/Promegakaryocytehttp://en.wikipedia.org/wiki/Erythrocytehttp://en.wikipedia.org/w/index.php?title=Orthochromatic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Polychromatic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Basophilic_erythroblast&action=edit&redlink=1http://en.wikipedia.org/wiki/Proerythroblasthttp://en.wikipedia.org/wiki/Basophilhttp://en.wikipedia.org/wiki/Eosinophilhttp://en.wikipedia.org/wiki/Neutrophilhttp://en.wikipedia.org/wiki/Metamyelocytehttp://en.wikipedia.org/wiki/Myelocytehttp://en.wikipedia.org/wiki/Promyelocytehttp://en.wikipedia.org/wiki/Myeloblasthttp://en.wikipedia.org/wiki/Monocytehttp://en.wikipedia.org/wiki/Monoblasthttp://en.wikipedia.org/wiki/Lymphocytehttp://en.wikipedia.org/wiki/Lymphoblasthttp://en.wikipedia.org/wiki/Progenitor_cellhttp://en.wikipedia.org/wiki/Hematopoietic_stem_cellhttp://en.wikipedia.org/wiki/Platelet#cite_note-9http://en.wikipedia.org/wiki/Platelet#cite_note-7http://en.wikipedia.org/wiki/Platelet#cite_note-7http://en.wikipedia.org/wiki/Platelet#cite_note-5http://en.wikipedia.org/wiki/Platelet#cite_note-5http://en.wikipedia.org/wiki/Platelet#cite_note-3http://en.wikipedia.org/wiki/Platelet#cite_note-3http://en.wikipedia.org/wiki/Wound_healinghttp://en.wikipedia.org/wiki/Platelet-rich_plasmahttp://en.wikipedia.org/wiki/Platelet-rich_plasmahttp://en.wikipedia.org/wiki/Vascular_endothelial_growth_factorhttp://en.wikipedia.org/wiki/Vascular_endothelial_growth_factorhttp://en.wikipedia.org/wiki/Epidermal_growth_factorhttp://en.wikipedia.org/wiki/Insulin-like_growth_factor_1http://en.wikipedia.org/wiki/Fibroblast_growth_factor


3/15

The lifespan of circulating platelets is 5 to 9 days. Old platelets are destroyed byphagocytosisin thespleenand byKupffer cellsin theliver.

Thrombus formation

Aggregation of platelets. Platelet rich human blood plasma (left vial) is a turbid liquid. Upon addition of

ADP, platelets are activated and start to aggregate, forming white flakes (right vial).

The function of platelets is the maintenance ofhemostasis. This is achieved primarily by the formation

of thrombi, when damage to the endothelium of blood vessels occurs. On the converse, thrombus

formation must be inhibited at times when there is no damage to the endothelium.

Activation

The inner surface of blood vessels is lined with a thin layer of endothelial cells that, in normal

hemostasis, acts to inhibit platelet activation by producing nitric oxide, endothelial-ADPase, and

PGI2. Endothelial-ADPase clears away the platelet activator,ADP.

Endothelial cells produce a protein called von Willebrand factor (vWF), a cell adhesion ligand, which

helps endothelial cells adhere tocollagenin thebasement membrane. Under physiological conditions,

collagen is not exposed to the bloodstream. vWF is secreted constitutively into the plasma by the

endothelial cells, and is stored in granules within the endothelial cell and in platelets.

When the endothelial layer is injured, collagen, vWF and tissue factor from the subendothelium is

exposed to the bloodstream. When the platelets contact collagen or vWF, they are activated (e.g. to

clump together). They are also activated bythrombin(formed with the help of tissue factor). They can

also be activated by a negatively charged surface, such as glass. Non-physiological flow conditions
http://en.wikipedia.org/wiki/Phagocytosishttp://en.wikipedia.org/wiki/Phagocytosishttp://en.wikipedia.org/wiki/Phagocytosishttp://en.wikipedia.org/wiki/Spleenhttp://en.wikipedia.org/wiki/Spleenhttp://en.wikipedia.org/wiki/Spleenhttp://en.wikipedia.org/wiki/Kupffer_cellhttp://en.wikipedia.org/wiki/Kupffer_cellhttp://en.wikipedia.org/wiki/Kupffer_cellhttp://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Endotheliumhttp://en.wikipedia.org/wiki/Endotheliumhttp://en.wikipedia.org/wiki/Blood_vesselhttp://en.wikipedia.org/wiki/Blood_vesselhttp://en.wikipedia.org/wiki/Endothelialhttp://en.wikipedia.org/wiki/Endothelialhttp://en.wikipedia.org/wiki/Nitric_oxidehttp://en.wikipedia.org/wiki/Nitric_oxidehttp://en.wikipedia.org/wiki/Prostacyclinhttp://en.wikipedia.org/wiki/Prostacyclinhttp://en.wikipedia.org/wiki/Prostacyclinhttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Ligand_(biochemistry)http://en.wikipedia.org/wiki/Ligand_(biochemistry)http://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Basement_membranehttp://en.wikipedia.org/wiki/Basement_membranehttp://en.wikipedia.org/wiki/Basement_membranehttp://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Tissue_factorhttp://en.wikipedia.org/wiki/Tissue_factorhttp://en.wikipedia.org/wiki/Thrombinhttp://en.wikipedia.org/wiki/Thrombinhttp://en.wikipedia.org/wiki/Thrombinhttp://en.wikipedia.org/wiki/File:Thrombocyteaggregation.jpghttp://en.wikipedia.org/wiki/File:Thrombocyteaggregation.jpghttp://en.wikipedia.org/wiki/File:Thrombocyteaggregation.jpghttp://en.wikipedia.org/wiki/File:Thrombocyteaggregation.jpghttp://en.wikipedia.org/wiki/Thrombinhttp://en.wikipedia.org/wiki/Tissue_factorhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Basement_membranehttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Ligand_(biochemistry)http://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Prostacyclinhttp://en.wikipedia.org/wiki/Nitric_oxidehttp://en.wikipedia.org/wiki/Endothelialhttp://en.wikipedia.org/wiki/Blood_vesselhttp://en.wikipedia.org/wiki/Endotheliumhttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Kupffer_cellhttp://en.wikipedia.org/wiki/Spleenhttp://en.wikipedia.org/wiki/Phagocytosis


4/15

(especially high values of shear stress) caused by arterial stenosis or artificial devices (Mechanical Heart

Valves, blood pumps etc) can also lead to platelet activation.[10]

Platelet activation further results in the scramblase-mediated transport of negatively charged

phospholipidsto the platelet surface. These phospholipids provide a catalytic surface (with the charge

provided by phosphatidylserine and phosphatidylethanolamine) for the tenase and prothrombinasecomplexes. Calcium ions are essential for binding of these coagulation factors.

Shape change :

Scanning electron micrograph of blood cells. From left to right: human erythrocyte, activated

thrombocyte (platelet),leukocyte.

Activated platelets change in shape to become more spherical, and pseudopods form on their

surface. Thus they assume astellateshape.

Granule secretion :

Platelets containalphaanddense granules. Activated platelets excrete the contents of these granules

into theircanalicular systemsand into surrounding blood. There are three types of granules:

dense (or delta) granules(containingADPorATP,calcium, andserotonin) lambda granules similar to lysosomes and contain several hydrolytic enzymes. Alpha granules(containingP-selectin,platelet factor 4,transforming growth factor-1,platelet-

derived growth factor,fibronectin,B-thromboglobulin,vWF,fibrinogen, andcoagulation factors

VandXIII).

Thromboxane A2 synthesis :

Platelet activation initiates thearachidonic acidpathway to produceTXA2. TXA2 is involved in activating

other platelets and its formation is inhibited byCOXinhibitors, such asaspirin.
http://en.wikipedia.org/wiki/Platelet#cite_note-10http://en.wikipedia.org/wiki/Platelet#cite_note-10http://en.wikipedia.org/wiki/Platelet#cite_note-10http://en.wikipedia.org/wiki/Scramblasehttp://en.wikipedia.org/wiki/Scramblasehttp://en.wikipedia.org/wiki/Phospholipidhttp://en.wikipedia.org/wiki/Phospholipidhttp://en.wikipedia.org/wiki/Phosphatidylserinehttp://en.wikipedia.org/wiki/Phosphatidylserinehttp://en.wikipedia.org/wiki/Phosphatidylethanolaminehttp://en.wikipedia.org/wiki/Phosphatidylethanolaminehttp://en.wikipedia.org/wiki/Tenasehttp://en.wikipedia.org/wiki/Tenasehttp://en.wikipedia.org/wiki/Prothrombinasehttp://en.wikipedia.org/wiki/Prothrombinasehttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Leukocytehttp://en.wikipedia.org/wiki/Leukocytehttp://en.wikipedia.org/wiki/Leukocytehttp://en.wikipedia.org/wiki/Pseudopodshttp://en.wikipedia.org/wiki/Pseudopodshttp://en.wiktionary.org/wiki/stellatehttp://en.wiktionary.org/wiki/stellatehttp://en.wiktionary.org/wiki/stellatehttp://en.wikipedia.org/wiki/Platelet_alpha-granulehttp://en.wikipedia.org/wiki/Platelet_alpha-granulehttp://en.wikipedia.org/wiki/Platelet_alpha-granulehttp://en.wikipedia.org/wiki/Dense_granulehttp://en.wikipedia.org/wiki/Dense_granulehttp://en.wikipedia.org/wiki/Dense_granulehttp://en.wikipedia.org/w/index.php?title=Canalicular_system&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Canalicular_system&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Canalicular_system&action=edit&redlink=1http://en.wikipedia.org/wiki/Dense_granulehttp://en.wikipedia.org/wiki/Dense_granulehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Serotoninhttp://en.wikipedia.org/wiki/Serotoninhttp://en.wikipedia.org/wiki/Serotoninhttp://en.wikipedia.org/wiki/Platelet_alpha-granulehttp://en.wikipedia.org/wiki/Platelet_alpha-granulehttp://en.wikipedia.org/wiki/P-selectinhttp://en.wikipedia.org/wiki/P-selectinhttp://en.wikipedia.org/wiki/P-selectinhttp://en.wikipedia.org/wiki/Platelet_factor_4http://en.wikipedia.org/wiki/Platelet_factor_4http://en.wikipedia.org/wiki/Platelet_factor_4http://en.wikipedia.org/wiki/TGF_beta_1http://en.wikipedia.org/wiki/TGF_beta_1http://en.wikipedia.org/wiki/TGF_beta_1http://en.wikipedia.org/wiki/TGF_beta_1http://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Fibronectinhttp://en.wikipedia.org/wiki/Fibronectinhttp://en.wikipedia.org/wiki/Fibronectinhttp://en.wikipedia.org/wiki/B-thromboglobulinhttp://en.wikipedia.org/wiki/B-thromboglobulinhttp://en.wikipedia.org/wiki/B-thromboglobulinhttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Fibrinogenhttp://en.wikipedia.org/wiki/Fibrinogenhttp://en.wikipedia.org/wiki/Fibrinogenhttp://en.wikipedia.org/wiki/Coagulation_factorhttp://en.wikipedia.org/wiki/Coagulation_factorhttp://en.wikipedia.org/wiki/Coagulation_factorhttp://en.wikipedia.org/wiki/Factor_Vhttp://en.wikipedia.org/wiki/Factor_Vhttp://en.wikipedia.org/wiki/Factor_XIIIhttp://en.wikipedia.org/wiki/Factor_XIIIhttp://en.wikipedia.org/wiki/Factor_XIIIhttp://en.wikipedia.org/wiki/Arachidonic_acidhttp://en.wikipedia.org/wiki/Arachidonic_acidhttp://en.wikipedia.org/wiki/Arachidonic_acidhttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/File:Red_White_Blood_cells.jpghttp://en.wikipedia.org/wiki/File:Red_White_Blood_cells.jpghttp://en.wikipedia.org/wiki/File:Red_White_Blood_cells.jpghttp://en.wikipedia.org/wiki/File:Red_White_Blood_cells.jpghttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/Arachidonic_acidhttp://en.wikipedia.org/wiki/Factor_XIIIhttp://en.wikipedia.org/wiki/Factor_Vhttp://en.wikipedia.org/wiki/Coagulation_factorhttp://en.wikipedia.org/wiki/Fibrinogenhttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/B-thromboglobulinhttp://en.wikipedia.org/wiki/Fibronectinhttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/TGF_beta_1http://en.wikipedia.org/wiki/Platelet_factor_4http://en.wikipedia.org/wiki/P-selectinhttp://en.wikipedia.org/wiki/Platelet_alpha-granulehttp://en.wikipedia.org/wiki/Serotoninhttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Dense_granulehttp://en.wikipedia.org/w/index.php?title=Canalicular_system&action=edit&redlink=1http://en.wikipedia.org/wiki/Dense_granulehttp://en.wikipedia.org/wiki/Platelet_alpha-granulehttp://en.wiktionary.org/wiki/stellatehttp://en.wikipedia.org/wiki/Pseudopodshttp://en.wikipedia.org/wiki/Leukocytehttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Prothrombinasehttp://en.wikipedia.org/wiki/Tenasehttp://en.wikipedia.org/wiki/Phosphatidylethanolaminehttp://en.wikipedia.org/wiki/Phosphatidylserinehttp://en.wikipedia.org/wiki/Phospholipidhttp://en.wikipedia.org/wiki/Scramblasehttp://en.wikipedia.org/wiki/Platelet#cite_note-10


5/15

Adhesion and aggregation :

Platelets clumping from a blood smear. May Grunwald-Giemsa. Light Microscopy, oil immersion 100x.

Platelets aggregate, or clump together, using fibrinogen and von Willebrand factor (vWF) as a

connecting agent. The most abundant platelet aggregation receptor is glycoprotein IIb/IIIa (gpIIb/IIIa);

this is a calcium-dependent receptor for fibrinogen,fibronectin,vitronectin,thrombospondin, and vWF.Other receptors include GPIb-V-IX complex (vWF) andGPVI(collagen).

Activated platelets will adhere, viaglycoprotein(GP) Ia, to the collagen that is exposed by endothelial

damage. Aggregation and adhesion act together to form the platelet plug. Myosinandactinfilaments in

platelets are stimulated to contract during aggregation, further reinforcing the plug.

Platelet aggregation is stimulated by ADP, thromboxane, and 2 receptor-activation, but inhibited by

other inflammatory products like PGI2 and PGD2. Platelet aggregation is enhanced by exogenous

administration of anabolic steroids.

Wound repair :

Main article:Wound repair

The blood clot is only a temporary solution to stop bleeding; vessel repair is therefore needed. The

aggregated platelets help this process by secreting chemicals that promote the invasion of fibroblasts

from surrounding connective tissue into the wounded area to completely heal the wound or form a scar.

The obstructing clot is slowly dissolved by the fibrinolytic enzyme,plasmin, and the platelets are cleared

byphagocytosis.

ADP (purinergic/P2) receptors:

Human platelets have three types of P2 receptors:P2X(1),P2Y(1) and P2Y(12). Although abnormalities in

all three genes have been documented, but clinical correlation is available only for P2Y(12) .[11]Patients

with P2Y(12) defects have a mild to moderate bleeding diathesis, characterized by mucocutaneous

bleeding and excessive post-surgical and post-traumatic blood loss. A defects in P2Y(12) should be

suspected when ADP, even at concentrations 10 micro molar, is unable to induce full, irreversible

platelet aggregation. Confirmation of the diagnosis is with tests that evaluate the degree of inhibition of

adenylyl cyclaseby ADP.
http://en.wikipedia.org/wiki/Fibrinogenhttp://en.wikipedia.org/wiki/Fibrinogenhttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Glycoprotein_IIb/IIIahttp://en.wikipedia.org/wiki/Glycoprotein_IIb/IIIahttp://en.wikipedia.org/wiki/Glycoprotein_IIb/IIIahttp://en.wikipedia.org/wiki/Fibronectinhttp://en.wikipedia.org/wiki/Fibronectinhttp://en.wikipedia.org/wiki/Fibronectinhttp://en.wikipedia.org/wiki/Vitronectinhttp://en.wikipedia.org/wiki/Vitronectinhttp://en.wikipedia.org/wiki/Vitronectinhttp://en.wikipedia.org/wiki/Thrombospondinhttp://en.wikipedia.org/wiki/Thrombospondinhttp://en.wikipedia.org/wiki/Thrombospondinhttp://en.wikipedia.org/wiki/GPVIhttp://en.wikipedia.org/wiki/GPVIhttp://en.wikipedia.org/wiki/GPVIhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Glycoproteinhttp://en.wikipedia.org/wiki/Glycoproteinhttp://en.wikipedia.org/wiki/Glycoproteinhttp://en.wikipedia.org/wiki/Myosinhttp://en.wikipedia.org/wiki/Myosinhttp://en.wikipedia.org/wiki/Myosinhttp://en.wikipedia.org/wiki/Actinhttp://en.wikipedia.org/wiki/Actinhttp://en.wikipedia.org/wiki/Actinhttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/%CE%912_receptorhttp://en.wikipedia.org/wiki/%CE%912_receptorhttp://en.wikipedia.org/wiki/%CE%912_receptorhttp://en.wikipedia.org/wiki/PGI2http://en.wikipedia.org/wiki/PGI2http://en.wikipedia.org/wiki/PGD2http://en.wikipedia.org/wiki/PGD2http://en.wikipedia.org/wiki/Wound_repairhttp://en.wikipedia.org/wiki/Wound_repairhttp://en.wikipedia.org/wiki/Wound_repairhttp://en.wikipedia.org/wiki/Fibroblastshttp://en.wikipedia.org/wiki/Fibroblastshttp://en.wikipedia.org/wiki/Fibroblastshttp://en.wikipedia.org/wiki/Plasminhttp://en.wikipedia.org/wiki/Plasminhttp://en.wikipedia.org/wiki/Plasminhttp://en.wikipedia.org/wiki/Phagocytosishttp://en.wikipedia.org/wiki/Phagocytosishttp://en.wikipedia.org/wiki/Phagocytosishttp://en.wikipedia.org/wiki/P2Xhttp://en.wikipedia.org/wiki/P2Xhttp://en.wikipedia.org/wiki/P2Xhttp://en.wikipedia.org/wiki/P2Y_receptorhttp://en.wikipedia.org/wiki/P2Y_receptorhttp://en.wikipedia.org/wiki/P2Y_receptorhttp://en.wikipedia.org/wiki/Platelet#cite_note-Cattaneo2011-11http://en.wikipedia.org/wiki/Platelet#cite_note-Cattaneo2011-11http://en.wikipedia.org/wiki/Platelet#cite_note-Cattaneo2011-11http://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Adenylyl_cyclasehttp://en.wikipedia.org/wiki/Adenylyl_cyclasehttp://en.wikipedia.org/wiki/File:Platelets.jpghttp://en.wikipedia.org/wiki/File:Platelets.jpghttp://en.wikipedia.org/wiki/File:Platelets.jpghttp://en.wikipedia.org/wiki/File:Platelets.jpghttp://en.wikipedia.org/wiki/Adenylyl_cyclasehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Platelet#cite_note-Cattaneo2011-11http://en.wikipedia.org/wiki/P2Y_receptorhttp://en.wikipedia.org/wiki/P2Xhttp://en.wikipedia.org/wiki/Phagocytosishttp://en.wikipedia.org/wiki/Plasminhttp://en.wikipedia.org/wiki/Fibroblastshttp://en.wikipedia.org/wiki/Wound_repairhttp://en.wikipedia.org/wiki/PGD2http://en.wikipedia.org/wiki/PGI2http://en.wikipedia.org/wiki/%CE%912_receptorhttp://en.wikipedia.org/wiki/Thromboxanehttp://en.wikipedia.org/wiki/Adenosine_diphosphatehttp://en.wikipedia.org/wiki/Actinhttp://en.wikipedia.org/wiki/Myosinhttp://en.wikipedia.org/wiki/Glycoproteinhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/GPVIhttp://en.wikipedia.org/wiki/Thrombospondinhttp://en.wikipedia.org/wiki/Vitronectinhttp://en.wikipedia.org/wiki/Fibronectinhttp://en.wikipedia.org/wiki/Glycoprotein_IIb/IIIahttp://en.wikipedia.org/wiki/Von_Willebrand_factorhttp://en.wikipedia.org/wiki/Fibrinogen


6/15

Other functions :

Clot retraction Procoagulant Inflammation Cytokinesignalling Phagocytosis[12]

Cytokine signaling :

In addition to being the chief cellular effector ofhemostasis, platelets are rapidly deployed to sites of

injury or infection, and potentially modulate inflammatory processes by interacting withleukocytesand

by secretingcytokines,chemokines, and other inflammatory mediators.[13][14][15][16]Platelets also secrete

platelet-derived growth factor(PDGF).

Role in disease:

Diagram of the internal structure of a platelet

High and low counts :

A normal platelet count in a healthy individual is between 150,000 and 450,000 per L (microlitre) of

blood ((150450)109/L).[17] Ninety-five percent of healthy people will have platelet counts in this

range. Some will have statistically abnormal platelet counts while having no demonstrable abnormality.

However, if it is either very low or very high, the likelihood of an abnormality being present is higher.

Both thrombocytopenia and thrombocytosismay present with coagulation problems. In general, low

platelet counts increase bleeding risks; however there are exceptions (such as immune-mediated

heparin-induced thrombocytopeniaorparoxysmal nocturnal hemoglobinuria). High counts may lead to

thrombosis, although this is mainly when the elevated count is due tomyeloproliferative disorder.
http://en.wikipedia.org/wiki/Clot_retractionhttp://en.wikipedia.org/wiki/Clot_retractionhttp://en.wikipedia.org/wiki/Inflammationhttp://en.wikipedia.org/wiki/Inflammationhttp://en.wikipedia.org/wiki/Cytokinehttp://en.wikipedia.org/wiki/Cytokinehttp://en.wikipedia.org/wiki/Platelet#cite_note-12http://en.wikipedia.org/wiki/Platelet#cite_note-12http://en.wikipedia.org/wiki/Platelet#cite_note-12http://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Leukocyteshttp://en.wikipedia.org/wiki/Leukocyteshttp://en.wikipedia.org/wiki/Leukocyteshttp://en.wikipedia.org/wiki/Cytokineshttp://en.wikipedia.org/wiki/Cytokineshttp://en.wikipedia.org/wiki/Cytokineshttp://en.wikipedia.org/wiki/Chemokineshttp://en.wikipedia.org/wiki/Chemokineshttp://en.wikipedia.org/wiki/Chemokineshttp://en.wikipedia.org/wiki/Platelet#cite_note-13http://en.wikipedia.org/wiki/Platelet#cite_note-13http://en.wikipedia.org/wiki/Platelet#cite_note-15http://en.wikipedia.org/wiki/Platelet#cite_note-15http://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Litrehttp://en.wikipedia.org/wiki/Litrehttp://en.wikipedia.org/wiki/Litrehttp://en.wikipedia.org/wiki/Platelet#cite_note-Kumar.26Clark-17http://en.wikipedia.org/wiki/Platelet#cite_note-Kumar.26Clark-17http://en.wikipedia.org/wiki/Platelet#cite_note-Kumar.26Clark-17http://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Paroxysmal_nocturnal_hemoglobinuriahttp://en.wikipedia.org/wiki/Paroxysmal_nocturnal_hemoglobinuriahttp://en.wikipedia.org/wiki/Paroxysmal_nocturnal_hemoglobinuriahttp://en.wikipedia.org/wiki/Thrombosishttp://en.wikipedia.org/wiki/Thrombosishttp://en.wikipedia.org/wiki/Myeloproliferative_disorderhttp://en.wikipedia.org/wiki/Myeloproliferative_disorderhttp://en.wikipedia.org/wiki/Myeloproliferative_disorderhttp://en.wikipedia.org/wiki/File:Platelet_structure.pnghttp://en.wikipedia.org/wiki/File:Platelet_structure.pnghttp://en.wikipedia.org/wiki/File:Platelet_structure.pnghttp://en.wikipedia.org/wiki/File:Platelet_structure.pnghttp://en.wikipedia.org/wiki/Myeloproliferative_disorderhttp://en.wikipedia.org/wiki/Thrombosishttp://en.wikipedia.org/wiki/Paroxysmal_nocturnal_hemoglobinuriahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Platelet#cite_note-Kumar.26Clark-17http://en.wikipedia.org/wiki/Litrehttp://en.wikipedia.org/wiki/Platelet-derived_growth_factorhttp://en.wikipedia.org/wiki/Platelet#cite_note-15http://en.wikipedia.org/wiki/Platelet#cite_note-15http://en.wikipedia.org/wiki/Platelet#cite_note-13http://en.wikipedia.org/wiki/Platelet#cite_note-13http://en.wikipedia.org/wiki/Chemokineshttp://en.wikipedia.org/wiki/Cytokineshttp://en.wikipedia.org/wiki/Leukocyteshttp://en.wikipedia.org/wiki/Hemostasishttp://en.wikipedia.org/wiki/Platelet#cite_note-12http://en.wikipedia.org/wiki/Cytokinehttp://en.wikipedia.org/wiki/Inflammationhttp://en.wikipedia.org/wiki/Clot_retraction


7/15

Transfusion is generally used only to correct unusually low platelet counts (typically below (10

15)109/L). Transfusion is contraindicated inthrombotic thrombocytopenic purpura(TTP), as it fuels the

coagulopathy. In patients undergoing surgery, a level below 50109/L is associated with abnormal

surgical bleeding, and regional anaesthetic procedures such asepidurals are avoided for levels below

80109/L.[18]

Normal platelet counts are not a guarantee of adequate function. In some states, the platelets, while

being adequate in number, are dysfunctional. For instance,aspirinirreversibly disrupts platelet function

by inhibitingcyclooxygenase-1 (COX1), and hence normal hemostasis. The resulting platelets are unable

to produce new cyclooxygenase because they have no DNA. Normal platelet function will not return

until the use of aspirin has ceased and enough of the affected platelets have been replaced by new

ones, which can take over a week. Ibuprofen, anotherNSAID, does not have such a long duration effect,

with platelet function usually returning within 24 hours,[19] and taking ibuprofen before aspirin

sometimes may prevent the irreversible effects of aspirin.[20] Uremia, a consequence of renal failure,

leads to platelet dysfunction that may be ameliorated by the administration ofdesmopressin.

Medications :

Oral agents often used to alter/suppress platelet function include aspirin, clopidogrel, cilostazol,

ticlopidine,ticagrelorandprasugrel.

Intravenous agents often used to alter/suppress platelet function include: abciximab, eptifibatide,

tirofiban.

In addition to platelet transfusion, hematopoetic agents such as Oprelvekin, Romiplostim, and

Eltrombopagcan be used to increase platelet counts.

Diseases :Disorders leading to a reduced platelet count:

Thrombocytopeniao Idiopathic thrombocytopenic purpura also known as immune thrombocytopenic

purpura (ITP)

o Thrombotic thrombocytopenic purpurao Drug-induced thrombocytopenic purpura (for example heparin-induced

thrombocytopenia(HIT))

Gaucher's disease Aplastic anemia Onyalai

Alloimmunedisorders
http://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Coagulopathyhttp://en.wikipedia.org/wiki/Coagulopathyhttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Regional_anaesthetichttp://en.wikipedia.org/wiki/Regional_anaesthetichttp://en.wikipedia.org/wiki/Regional_anaesthetichttp://en.wikipedia.org/wiki/Epiduralhttp://en.wikipedia.org/wiki/Epiduralhttp://en.wikipedia.org/wiki/Epiduralhttp://en.wikipedia.org/wiki/Platelet#cite_note-18http://en.wikipedia.org/wiki/Platelet#cite_note-18http://en.wikipedia.org/wiki/Platelet#cite_note-18http://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Ibuprofenhttp://en.wikipedia.org/wiki/Ibuprofenhttp://en.wikipedia.org/wiki/NSAIDhttp://en.wikipedia.org/wiki/NSAIDhttp://en.wikipedia.org/wiki/NSAIDhttp://en.wikipedia.org/wiki/Platelet#cite_note-19http://en.wikipedia.org/wiki/Platelet#cite_note-19http://en.wikipedia.org/wiki/Platelet#cite_note-19http://en.wikipedia.org/wiki/Platelet#cite_note-20http://en.wikipedia.org/wiki/Platelet#cite_note-20http://en.wikipedia.org/wiki/Platelet#cite_note-20http://en.wikipedia.org/wiki/Uremiahttp://en.wikipedia.org/wiki/Uremiahttp://en.wikipedia.org/wiki/Renal_failurehttp://en.wikipedia.org/wiki/Renal_failurehttp://en.wikipedia.org/wiki/Renal_failurehttp://en.wikipedia.org/wiki/Desmopressinhttp://en.wikipedia.org/wiki/Desmopressinhttp://en.wikipedia.org/wiki/Desmopressinhttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Clopidogrelhttp://en.wikipedia.org/wiki/Clopidogrelhttp://en.wikipedia.org/wiki/Cilostazolhttp://en.wikipedia.org/wiki/Cilostazolhttp://en.wikipedia.org/wiki/Ticlopidinehttp://en.wikipedia.org/wiki/Ticlopidinehttp://en.wikipedia.org/wiki/Ticagrelorhttp://en.wikipedia.org/wiki/Ticagrelorhttp://en.wikipedia.org/wiki/Ticagrelorhttp://en.wikipedia.org/wiki/Prasugrelhttp://en.wikipedia.org/wiki/Prasugrelhttp://en.wikipedia.org/wiki/Prasugrelhttp://en.wikipedia.org/wiki/Abciximabhttp://en.wikipedia.org/wiki/Abciximabhttp://en.wikipedia.org/wiki/Eptifibatidehttp://en.wikipedia.org/wiki/Eptifibatidehttp://en.wikipedia.org/wiki/Tirofibanhttp://en.wikipedia.org/wiki/Tirofibanhttp://en.wikipedia.org/wiki/Oprelvekinhttp://en.wikipedia.org/wiki/Oprelvekinhttp://en.wikipedia.org/wiki/Romiplostimhttp://en.wikipedia.org/wiki/Romiplostimhttp://en.wikipedia.org/wiki/Eltrombopaghttp://en.wikipedia.org/wiki/Eltrombopaghttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Idiopathic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Idiopathic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Drug-induced_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Drug-induced_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Gaucher%27s_diseasehttp://en.wikipedia.org/wiki/Gaucher%27s_diseasehttp://en.wikipedia.org/wiki/Aplastic_anemiahttp://en.wikipedia.org/wiki/Aplastic_anemiahttp://en.wikipedia.org/wiki/Onyalaihttp://en.wikipedia.org/wiki/Onyalaihttp://en.wikipedia.org/wiki/Alloimmunehttp://en.wikipedia.org/wiki/Alloimmunehttp://en.wikipedia.org/wiki/Alloimmunehttp://en.wikipedia.org/wiki/Onyalaihttp://en.wikipedia.org/wiki/Aplastic_anemiahttp://en.wikipedia.org/wiki/Gaucher%27s_diseasehttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Heparin-induced_thrombocytopeniahttp://en.wikipedia.org/wiki/Drug-induced_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Idiopathic_thrombocytopenic_purpurahttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Eltrombopaghttp://en.wikipedia.org/wiki/Romiplostimhttp://en.wikipedia.org/wiki/Oprelvekinhttp://en.wikipedia.org/wiki/Tirofibanhttp://en.wikipedia.org/wiki/Eptifibatidehttp://en.wikipedia.org/wiki/Abciximabhttp://en.wikipedia.org/wiki/Prasugrelhttp://en.wikipedia.org/wiki/Ticagrelorhttp://en.wikipedia.org/wiki/Ticlopidinehttp://en.wikipedia.org/wiki/Cilostazolhttp://en.wikipedia.org/wiki/Clopidogrelhttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Desmopressinhttp://en.wikipedia.org/wiki/Renal_failurehttp://en.wikipedia.org/wiki/Uremiahttp://en.wikipedia.org/wiki/Platelet#cite_note-20http://en.wikipedia.org/wiki/Platelet#cite_note-19http://en.wikipedia.org/wiki/NSAIDhttp://en.wikipedia.org/wiki/Ibuprofenhttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Platelet#cite_note-18http://en.wikipedia.org/wiki/Epiduralhttp://en.wikipedia.org/wiki/Regional_anaesthetichttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Coagulopathyhttp://en.wikipedia.org/wiki/Thrombotic_thrombocytopenic_purpura


8/15

Fetomaternal alloimmune thrombocytopenia Some transfusion reactions

Disorders leading to platelet dysfunction or reduced count:

HELLP syndrome Hemolytic-uremic syndrome Chemotherapy Dengue

Disorders featuring an elevated count:

Thrombocytosis, including essential thrombocytosis (elevated counts, either reactive or as anexpression ofmyeloproliferative disease); may feature dysfunctional platelets

Disorders of platelet adhesion or aggregation:

Bernard-Soulier syndrome Glanzmann thrombasthenia

Disorders of platelet granule amount or release

Hermansky-Pudlak Syndrome Gray platelet syndrome

Disorders of platelet metabolism

Decreasedcyclooxygenaseactivity, induced or congenital Storage pool defects, acquired or congenital

Disorders that compromise platelet signaling:

WiskottAldrich syndromeDisorders in which platelets play a key role:

Atherosclerosis Coronary artery disease, CAD andmyocardial infarction, MI Cerebrovascular diseaseandStroke, CVA (cerebrovascular accident) Peripheral artery occlusive disease(PAOD)
http://en.wikipedia.org/wiki/Fetomaternal_alloimmune_thrombocytopeniahttp://en.wikipedia.org/wiki/Fetomaternal_alloimmune_thrombocytopeniahttp://en.wikipedia.org/wiki/HELLP_syndromehttp://en.wikipedia.org/wiki/HELLP_syndromehttp://en.wikipedia.org/wiki/Hemolytic-uremic_syndromehttp://en.wikipedia.org/wiki/Hemolytic-uremic_syndromehttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Denguehttp://en.wikipedia.org/wiki/Denguehttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Essential_thrombocytosishttp://en.wikipedia.org/wiki/Essential_thrombocytosishttp://en.wikipedia.org/wiki/Essential_thrombocytosishttp://en.wikipedia.org/wiki/Myeloproliferative_diseasehttp://en.wikipedia.org/wiki/Myeloproliferative_diseasehttp://en.wikipedia.org/wiki/Myeloproliferative_diseasehttp://en.wikipedia.org/wiki/Bernard-Soulier_syndromehttp://en.wikipedia.org/wiki/Bernard-Soulier_syndromehttp://en.wikipedia.org/wiki/Glanzmann_thrombastheniahttp://en.wikipedia.org/wiki/Glanzmann_thrombastheniahttp://en.wikipedia.org/wiki/Hermansky-Pudlak_Syndromehttp://en.wikipedia.org/wiki/Hermansky-Pudlak_Syndromehttp://en.wikipedia.org/wiki/Gray_platelet_syndromehttp://en.wikipedia.org/wiki/Gray_platelet_syndromehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Wiskott%E2%80%93Aldrich_syndromehttp://en.wikipedia.org/wiki/Wiskott%E2%80%93Aldrich_syndromehttp://en.wikipedia.org/wiki/Wiskott%E2%80%93Aldrich_syndromehttp://en.wikipedia.org/wiki/Wiskott%E2%80%93Aldrich_syndromehttp://en.wikipedia.org/wiki/Atherosclerosishttp://en.wikipedia.org/wiki/Atherosclerosishttp://en.wikipedia.org/wiki/Coronary_artery_diseasehttp://en.wikipedia.org/wiki/Coronary_artery_diseasehttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Cerebrovascular_diseasehttp://en.wikipedia.org/wiki/Cerebrovascular_diseasehttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Peripheral_artery_occlusive_diseasehttp://en.wikipedia.org/wiki/Peripheral_artery_occlusive_diseasehttp://en.wikipedia.org/wiki/Peripheral_artery_occlusive_diseasehttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Cerebrovascular_diseasehttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Coronary_artery_diseasehttp://en.wikipedia.org/wiki/Atherosclerosishttp://en.wikipedia.org/wiki/Wiskott%E2%80%93Aldrich_syndromehttp://en.wikipedia.org/wiki/Cyclooxygenasehttp://en.wikipedia.org/wiki/Gray_platelet_syndromehttp://en.wikipedia.org/wiki/Hermansky-Pudlak_Syndromehttp://en.wikipedia.org/wiki/Glanzmann_thrombastheniahttp://en.wikipedia.org/wiki/Bernard-Soulier_syndromehttp://en.wikipedia.org/wiki/Myeloproliferative_diseasehttp://en.wikipedia.org/wiki/Essential_thrombocytosishttp://en.wikipedia.org/wiki/Thrombocytosishttp://en.wikipedia.org/wiki/Denguehttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Hemolytic-uremic_syndromehttp://en.wikipedia.org/wiki/HELLP_syndromehttp://en.wikipedia.org/wiki/Fetomaternal_alloimmune_thrombocytopenia


9/15

Cancer[21] Malaria[22] Asthma[23][24] Samters Triad (Aspirin Exacerbated Respiratory Disease/AERD)[25][26]

Laboratory findings in various platelet and coagulation disorders (V-T)

ConditionProthrombin

time

Partial

thromboplastin time

Bleeding

timePlatelet count

Vitamin K deficiencyorwarfarin ProlongedNormal or mildly

prolongedUnaffected Unaffected

Disseminated intravascular

coagulation Prolonged Prolonged Prolonged Decreased

Von Willebrand disease Unaffected Prolonged Prolonged Unaffected

Hemophilia Unaffected Prolonged Unaffected Unaffected

Aspirin Unaffected Unaffected Prolonged Unaffected

Thrombocytopenia Unaffected Unaffected Prolonged Decreased

Liver failure, early Prolonged Unaffected Unaffected Unaffected

Liver failure, end-stage Prolonged Prolonged Prolonged Decreased

Uremia Unaffected Unaffected Prolonged Unaffected

Congenital afibrinogenemia Prolonged Prolonged Prolonged Unaffected

Factor Vdeficiency Prolonged Prolonged Unaffected Unaffected

Factor X deficiency as seen in

amyloid purpura Prolonged Prolonged Unaffected Unaffected

Glanzmann's thrombasthenia Unaffected Unaffected Prolonged Unaffected

Bernard-Soulier syndrome Unaffected Unaffected ProlongedDecreased or

unaffected
http://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Malariahttp://en.wikipedia.org/wiki/Malariahttp://en.wikipedia.org/wiki/Malariahttp://en.wikipedia.org/wiki/Asthmahttp://en.wikipedia.org/wiki/Asthmahttp://en.wikipedia.org/wiki/Platelet#cite_note-24http://en.wikipedia.org/wiki/Platelet#cite_note-24http://en.wikipedia.org/wiki/Aspirin-induced_asthmahttp://en.wikipedia.org/wiki/Aspirin-induced_asthmahttp://en.wikipedia.org/wiki/Platelet#cite_note-26http://en.wikipedia.org/wiki/Platelet#cite_note-26http://en.wikipedia.org/wiki/Template:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template_talk:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template_talk:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template_talk:Bleeding_worksheethttp://en.wikipedia.org/wiki/Prothrombin_timehttp://en.wikipedia.org/wiki/Prothrombin_timehttp://en.wikipedia.org/wiki/Partial_thromboplastin_timehttp://en.wikipedia.org/wiki/Partial_thromboplastin_timehttp://en.wikipedia.org/wiki/Bleeding_timehttp://en.wikipedia.org/wiki/Bleeding_timehttp://en.wikipedia.org/wiki/Platelet_counthttp://en.wikipedia.org/wiki/Vitamin_K_deficiencyhttp://en.wikipedia.org/wiki/Vitamin_K_deficiencyhttp://en.wikipedia.org/wiki/Warfarinhttp://en.wikipedia.org/wiki/Warfarinhttp://en.wikipedia.org/wiki/Warfarinhttp://en.wikipedia.org/wiki/Disseminated_intravascular_coagulationhttp://en.wikipedia.org/wiki/Disseminated_intravascular_coagulationhttp://en.wikipedia.org/wiki/Von_Willebrand_diseasehttp://en.wikipedia.org/wiki/Hemophiliahttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Liver_failurehttp://en.wikipedia.org/wiki/Liver_failurehttp://en.wikipedia.org/wiki/Uremiahttp://en.wikipedia.org/wiki/Congenital_afibrinogenemiahttp://en.wikipedia.org/wiki/Congenital_afibrinogenemiahttp://en.wikipedia.org/wiki/Factor_Vhttp://en.wikipedia.org/wiki/Factor_Vhttp://en.wikipedia.org/wiki/Factor_Xhttp://en.wikipedia.org/wiki/Factor_Xhttp://en.wikipedia.org/wiki/Amyloid_purpurahttp://en.wikipedia.org/wiki/Amyloid_purpurahttp://en.wikipedia.org/wiki/Glanzmann%27s_thrombastheniahttp://en.wikipedia.org/wiki/Glanzmann%27s_thrombastheniahttp://en.wikipedia.org/wiki/Bernard-Soulier_syndromehttp://en.wikipedia.org/wiki/Bernard-Soulier_syndromehttp://en.wikipedia.org/wiki/Glanzmann%27s_thrombastheniahttp://en.wikipedia.org/wiki/Amyloid_purpurahttp://en.wikipedia.org/wiki/Factor_Xhttp://en.wikipedia.org/wiki/Factor_Vhttp://en.wikipedia.org/wiki/Congenital_afibrinogenemiahttp://en.wikipedia.org/wiki/Uremiahttp://en.wikipedia.org/wiki/Liver_failurehttp://en.wikipedia.org/wiki/Thrombocytopeniahttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Hemophiliahttp://en.wikipedia.org/wiki/Von_Willebrand_diseasehttp://en.wikipedia.org/wiki/Disseminated_intravascular_coagulationhttp://en.wikipedia.org/wiki/Disseminated_intravascular_coagulationhttp://en.wikipedia.org/wiki/Warfarinhttp://en.wikipedia.org/wiki/Vitamin_K_deficiencyhttp://en.wikipedia.org/wiki/Platelet_counthttp://en.wikipedia.org/wiki/Bleeding_timehttp://en.wikipedia.org/wiki/Bleeding_timehttp://en.wikipedia.org/wiki/Partial_thromboplastin_timehttp://en.wikipedia.org/wiki/Partial_thromboplastin_timehttp://en.wikipedia.org/wiki/Prothrombin_timehttp://en.wikipedia.org/wiki/Prothrombin_timehttp://en.wikipedia.org/wiki/Template_talk:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template:Bleeding_worksheethttp://en.wikipedia.org/wiki/Platelet#cite_note-26http://en.wikipedia.org/wiki/Aspirin-induced_asthmahttp://en.wikipedia.org/wiki/Aspirin-induced_asthmahttp://en.wikipedia.org/wiki/Platelet#cite_note-24http://en.wikipedia.org/wiki/Asthmahttp://en.wikipedia.org/wiki/Asthmahttp://en.wikipedia.org/wiki/Malariahttp://en.wikipedia.org/wiki/Malariahttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Cancer


10/15

Laboratory findings in various platelet and coagulation disorders (V-T)

ConditionProthrombin

time

Partial

thromboplastin time

Bleeding

timePlatelet count

Factor XII deficiency Unaffected Prolonged Unaffected Unaffected

C1INH deficiency Unaffected Shortened Unaffected Unaffected

Discovery :

Although red blood cells had been known sincevan Leeuwenhoek(16321723), the German anatomist

Max Schultze(18251874) was the first to describe platelets.[27][28] He described "spherules" that were

much smaller than red blood cells and that occasionally clumped and were found in collections of

fibrous material.

Giulio Bizzozero (18461901), building on Schultze's findings, used "living circulation" to study bloodcells of amphibians microscopicallyin vivo. He is especially noted for discovering that platelets clump at

the site of blood vessel injury, a process that precedes the formation of ablood clot. This observation

confirmed the role of platelets incoagulation.[29]

In transfusion medicine :

Platelet concentrate.

Platelets are either isolated from collected units ofwhole bloodand pooled to make a therapeutic dose

or collected byapheresis, sometimes concurrently withplasmaorred blood cells. The industry standard

is for platelets to be tested forbacteriabefore transfusion to avoid septic reactions, which can be fatal.
http://en.wikipedia.org/wiki/Template:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template_talk:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template_talk:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template_talk:Bleeding_worksheethttp://en.wikipedia.org/wiki/Prothrombin_timehttp://en.wikipedia.org/wiki/Prothrombin_timehttp://en.wikipedia.org/wiki/Partial_thromboplastin_timehttp://en.wikipedia.org/wiki/Partial_thromboplastin_timehttp://en.wikipedia.org/wiki/Bleeding_timehttp://en.wikipedia.org/wiki/Bleeding_timehttp://en.wikipedia.org/wiki/Platelet_counthttp://en.wikipedia.org/wiki/Factor_XII#Role_in_diseasehttp://en.wikipedia.org/wiki/Hereditary_Angioedemahttp://en.wikipedia.org/wiki/Anton_van_Leeuwenhoekhttp://en.wikipedia.org/wiki/Anton_van_Leeuwenhoekhttp://en.wikipedia.org/wiki/Anton_van_Leeuwenhoekhttp://en.wikipedia.org/wiki/Max_Johann_Sigismund_Schultzehttp://en.wikipedia.org/wiki/Max_Johann_Sigismund_Schultzehttp://en.wikipedia.org/wiki/Platelet#cite_note-Brewer-27http://en.wikipedia.org/wiki/Platelet#cite_note-Brewer-27http://en.wikipedia.org/wiki/Platelet#cite_note-Brewer-27http://en.wikipedia.org/wiki/Fibrinhttp://en.wikipedia.org/wiki/Fibrinhttp://en.wikipedia.org/wiki/Giulio_Bizzozerohttp://en.wikipedia.org/wiki/Giulio_Bizzozerohttp://en.wikipedia.org/wiki/In_vivohttp://en.wikipedia.org/wiki/In_vivohttp://en.wikipedia.org/wiki/In_vivohttp://en.wikipedia.org/wiki/Thrombushttp://en.wikipedia.org/wiki/Thrombushttp://en.wikipedia.org/wiki/Thrombushttp://en.wikipedia.org/wiki/Coagulationhttp://en.wikipedia.org/wiki/Coagulationhttp://en.wikipedia.org/wiki/Platelet#cite_note-Bizzozero-29http://en.wikipedia.org/wiki/Platelet#cite_note-Bizzozero-29http://en.wikipedia.org/wiki/Platelet#cite_note-Bizzozero-29http://en.wikipedia.org/wiki/Whole_bloodhttp://en.wikipedia.org/wiki/Whole_bloodhttp://en.wikipedia.org/wiki/Whole_bloodhttp://en.wikipedia.org/wiki/Apheresishttp://en.wikipedia.org/wiki/Apheresishttp://en.wikipedia.org/wiki/Apheresishttp://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Red_blood_cellshttp://en.wikipedia.org/wiki/Red_blood_cellshttp://en.wikipedia.org/wiki/Red_blood_cellshttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/File:Platelet_blood_bag.jpghttp://en.wikipedia.org/wiki/File:Platelet_blood_bag.jpghttp://en.wikipedia.org/wiki/File:Platelet_blood_bag.jpghttp://en.wikipedia.org/wiki/File:Platelet_blood_bag.jpghttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Red_blood_cellshttp://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Apheresishttp://en.wikipedia.org/wiki/Whole_bloodhttp://en.wikipedia.org/wiki/Platelet#cite_note-Bizzozero-29http://en.wikipedia.org/wiki/Coagulationhttp://en.wikipedia.org/wiki/Thrombushttp://en.wikipedia.org/wiki/In_vivohttp://en.wikipedia.org/wiki/Giulio_Bizzozerohttp://en.wikipedia.org/wiki/Fibrinhttp://en.wikipedia.org/wiki/Platelet#cite_note-Brewer-27http://en.wikipedia.org/wiki/Platelet#cite_note-Brewer-27http://en.wikipedia.org/wiki/Max_Johann_Sigismund_Schultzehttp://en.wikipedia.org/wiki/Anton_van_Leeuwenhoekhttp://en.wikipedia.org/wiki/Hereditary_Angioedemahttp://en.wikipedia.org/wiki/Factor_XII#Role_in_diseasehttp://en.wikipedia.org/wiki/Platelet_counthttp://en.wikipedia.org/wiki/Bleeding_timehttp://en.wikipedia.org/wiki/Bleeding_timehttp://en.wikipedia.org/wiki/Partial_thromboplastin_timehttp://en.wikipedia.org/wiki/Partial_thromboplastin_timehttp://en.wikipedia.org/wiki/Prothrombin_timehttp://en.wikipedia.org/wiki/Prothrombin_timehttp://en.wikipedia.org/wiki/Template_talk:Bleeding_worksheethttp://en.wikipedia.org/wiki/Template:Bleeding_worksheet


11/15

Recently the AABB Industry Standards for Blood Banks and Transfusion Services (5.1.5.1) has allowed for

use of pathogen reduction technology as an alternative to bacterial screenings in platelets.[30]

Pooled whole-blood platelets, sometimes called random platelets, are made primarily by two

methods.[31]In the US, a unit of whole blood is placed into a largecentrifugein what is referred to as a

soft spin. At these settings, the platelets remain suspended in the plasma. The platelet-rich plasma(PRP) is removed from the RBCs, then centrifuged at a faster setting to harvest the platelets from the

plasma. In other regions of the world, the unit of whole blood is centrifuged using settings that cause

the platelets to become suspended in the buffy coat layer, which includes the platelets and the white

blood cells. The buffy coat is isolated in a sterile bag, suspended in a small amount of red blood cells

and plasma, then centrifuged again to separate the platelets and plasma from the red and white blood

cells. Regardless of the initial method of preparation, multiple donations may be combined into one

container using a sterile connection device to manufacture a single product with the desired therapeutic

dose.

Apheresis platelets are collected using a mechanical device that draws blood from the donor and

centrifuges the collected blood to separate out the platelets and other components to be collected. The

remaining blood is returned to the donor. The advantage to this method is that a single donation

provides at least one therapeutic dose, as opposed to the multiple donations for whole-blood platelets.

This means that a recipient is not exposed to as many different donors and has less risk of transfusion-

transmitted disease and other complications. Sometimes a person such as acancerpatient who requires

routine transfusions of platelets will receive repeated donations from a specific donor to further

minimize the risk. Pathogen reduction of platelets using for example,riboflavin and UV light treatments

can also be carried out to reduce the infectious load of pathogens contained in donated blood products,

thereby reducing the risk of transmission of transfusion transmitted diseases.[32][33]

Platelets are not cross-matched unless they contain a significant amount ofred blood cells(RBCs), which

results in a reddish-orange color to the product. This is usually associated with whole-blood platelets, as

apheresis methods are more efficient than soft spin centrifugation at isolating the specific

components of blood. An effort is usually made to issue type specific platelets, but this is not as critical

as it is with RBCs.

Platelets collected by either method have a very short shelf life, typically five days. This results in

frequent problems with short supply, as testing the donations often requires up to a full day. Since there

are no effective preservative solutions for platelets, they lose potency quickly and are best when fresh.

Platelets are stored under constant agitation at 2024 C. Storage at room temperature provides anenvironment where any bacteria that are introduced to the blood component during the collection

process may proliferate and subsequently causebacteremia in the patient. Regulations are in place in

the United States that require products to be tested for the presence of bacterial contamination before

transfusion.[34]

Platelets, either apheresis or random-donor platelets, can be processed through a volume reduction

process. In this process, the platelets are spun in a centrifuge and the excess plasma is removed, leaving
http://en.wikipedia.org/wiki/Platelet#cite_note-30http://en.wikipedia.org/wiki/Platelet#cite_note-30http://en.wikipedia.org/wiki/Platelet#cite_note-30http://en.wikipedia.org/wiki/Platelet#cite_note-31http://en.wikipedia.org/wiki/Platelet#cite_note-31http://en.wikipedia.org/wiki/Platelet#cite_note-31http://en.wikipedia.org/wiki/Centrifugehttp://en.wikipedia.org/wiki/Centrifugehttp://en.wikipedia.org/wiki/Centrifugehttp://en.wikipedia.org/wiki/Platelet-rich_plasmahttp://en.wikipedia.org/wiki/Platelet-rich_plasmahttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Pathogen_reduction_using_riboflavin_and_UV_lighthttp://en.wikipedia.org/wiki/Pathogen_reduction_using_riboflavin_and_UV_lighthttp://en.wikipedia.org/wiki/Pathogen_reduction_using_riboflavin_and_UV_lighthttp://en.wikipedia.org/wiki/Platelet#cite_note-32http://en.wikipedia.org/wiki/Platelet#cite_note-32http://en.wikipedia.org/wiki/Platelet#cite_note-32http://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Bacteremiahttp://en.wikipedia.org/wiki/Bacteremiahttp://en.wikipedia.org/wiki/Bacteremiahttp://en.wikipedia.org/wiki/Platelet#cite_note-34http://en.wikipedia.org/wiki/Platelet#cite_note-34http://en.wikipedia.org/wiki/Platelet#cite_note-34http://en.wikipedia.org/wiki/Platelet#cite_note-34http://en.wikipedia.org/wiki/Bacteremiahttp://en.wikipedia.org/wiki/Red_blood_cellhttp://en.wikipedia.org/wiki/Platelet#cite_note-32http://en.wikipedia.org/wiki/Platelet#cite_note-32http://en.wikipedia.org/wiki/Pathogen_reduction_using_riboflavin_and_UV_lighthttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Platelet-rich_plasmahttp://en.wikipedia.org/wiki/Centrifugehttp://en.wikipedia.org/wiki/Platelet#cite_note-31http://en.wikipedia.org/wiki/Platelet#cite_note-30


12/15

10 to 100 mL of platelet concentrate. Volume-reduced platelets are normally transfused only to

neonatal and pediatric patients when a large volume of plasma could overload the child's small

circulatory system. The lower volume of plasma also reduces the chances of an adverse transfusion

reaction to plasma proteins.[35]Volume reduced platelets have a shelf life of only four hours.[36]

Other species:

Nucleated thrombocytes of nonmammalian vertebrates differ from the mammalian thrombocytes not

only in having a nucleus and resembling B lymphocytes, but also these nucleated thrombocytes do not

aggregate in response to ADP, serotonin and adrenaline (although they do aggregate with thrombin).

References :

1. Campbell, Neil A. (2008). Biology (8th ed.). London: Pearson Education. p. 912.ISBN978-0-321-53616-7. "Platelets are pinched-off cytoplasmic fragments of specialized

bone marrow cells. They are about 23m in diameter and have no nuclei. Platelets

serve both structural and molecular functions in blood clotting."

2. Maton, Anthea; Jean Hopkins, Charles William McLaughlin, Susan Johnson, MaryannaQuon Warner, David LaHart, Jill D. Wright (1993). Human Biology and Health.

Englewood Cliffs NJ: Prentice Hall.ISBN0-13-981176-1.

3. O'Connell SM, Impeduglia T, Hessler K, Wang XJ, Carroll RJ, Dardik H (2008)."Autologous platelet-rich fibrin matrix as cell therapy in the healing of chronic lower-

extremity ulcers". Wound Repair Regen 16 (6): 74956. doi:10.1111/j.1524-

475X.2008.00426.x.PMID19128245.

4. Snchez M, Anitua E, Azofra J, Anda I, Padilla S, Mujika I (2007). "Comparison ofsurgically repaired Achilles tendon tears using platelet-rich fibrin matrices".Am J Sports

Med35 (2): 24551.doi:10.1177/0363546506294078.PMID17099241.

5. Knighton DR, Ciresi KF, Fiegel VD, Austin LL, Butler EL (1986). "Classification andtreatment of chronic nonhealing wounds. Successful treatment with autologous

platelet-derived wound healing factors (PDWHF)". Ann. Surg. 204 (3): 32230.

PMC1251286.PMID3753059.

6. Knighton DR, Ciresi K, Fiegel VD, Schumerth S, Butler E, Cerra F (1990). "Stimulation ofrepair in chronic, nonhealing, cutaneous ulcers using platelet-derived wound healing

formula". Surg Gynecol Obstet170 (1): 5660.PMID2403699.

7. Celotti F, Colciago A, Negri-Cesi P, Pravettoni A, Zaninetti R, Sacchi MC (2006). "Effect ofplatelet-rich plasma on migration and proliferation of SaOS-2 osteoblasts: role of

platelet-derived growth factor and transforming growth factor-beta". Wound Repair

Regen14 (2): 195202.doi:10.1111/j.1743-6109.2006.00110.x.PMID16630109.
http://en.wikipedia.org/wiki/Neonatalhttp://en.wikipedia.org/wiki/Neonatalhttp://en.wikipedia.org/wiki/Pediatrichttp://en.wikipedia.org/wiki/Pediatrichttp://en.wikipedia.org/wiki/Platelet#cite_note-pmid16537051-35http://en.wikipedia.org/wiki/Platelet#cite_note-pmid16537051-35http://en.wikipedia.org/wiki/Platelet#cite_note-pmid16537051-35http://en.wikipedia.org/wiki/Platelet#cite_note-36http://en.wikipedia.org/wiki/Platelet#cite_note-36http://en.wikipedia.org/wiki/Platelet#cite_note-36http://en.wikipedia.org/wiki/Neil_Campbell_(scientist)http://en.wikipedia.org/wiki/Neil_Campbell_(scientist)http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/Special:BookSources/978-0-321-53616-7http://en.wikipedia.org/wiki/Special:BookSources/978-0-321-53616-7http://en.wikipedia.org/wiki/Special:BookSources/978-0-321-53616-7http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/Special:BookSources/0-13-981176-1http://en.wikipedia.org/wiki/Special:BookSources/0-13-981176-1http://en.wikipedia.org/wiki/Special:BookSources/0-13-981176-1http://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1111%2Fj.1524-475X.2008.00426.xhttp://dx.doi.org/10.1111%2Fj.1524-475X.2008.00426.xhttp://dx.doi.org/10.1111%2Fj.1524-475X.2008.00426.xhttp://dx.doi.org/10.1111%2Fj.1524-475X.2008.00426.xhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/19128245http://www.ncbi.nlm.nih.gov/pubmed/19128245http://www.ncbi.nlm.nih.gov/pubmed/19128245http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1177%2F0363546506294078http://dx.doi.org/10.1177%2F0363546506294078http://dx.doi.org/10.1177%2F0363546506294078http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/17099241http://www.ncbi.nlm.nih.gov/pubmed/17099241http://www.ncbi.nlm.nih.gov/pubmed/17099241http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://en.wikipedia.org/wiki/PubMed_Centralhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/3753059http://www.ncbi.nlm.nih.gov/pubmed/3753059http://www.ncbi.nlm.nih.gov/pubmed/3753059http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/2403699http://www.ncbi.nlm.nih.gov/pubmed/2403699http://www.ncbi.nlm.nih.gov/pubmed/2403699http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1111%2Fj.1743-6109.2006.00110.xhttp://dx.doi.org/10.1111%2Fj.1743-6109.2006.00110.xhttp://dx.doi.org/10.1111%2Fj.1743-6109.2006.00110.xhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/16630109http://www.ncbi.nlm.nih.gov/pubmed/16630109http://www.ncbi.nlm.nih.gov/pubmed/16630109http://www.ncbi.nlm.nih.gov/pubmed/16630109http://en.wikipedia.org/wiki/PubMed_Identifierhttp://dx.doi.org/10.1111%2Fj.1743-6109.2006.00110.xhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.ncbi.nlm.nih.gov/pubmed/2403699http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/3753059http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://en.wikipedia.org/wiki/PubMed_Centralhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1251286http://www.ncbi.nlm.nih.gov/pubmed/17099241http://en.wikipedia.org/wiki/PubMed_Identifierhttp://dx.doi.org/10.1177%2F0363546506294078http://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.ncbi.nlm.nih.gov/pubmed/19128245http://en.wikipedia.org/wiki/PubMed_Identifierhttp://dx.doi.org/10.1111%2Fj.1524-475X.2008.00426.xhttp://dx.doi.org/10.1111%2Fj.1524-475X.2008.00426.xhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/Special:BookSources/0-13-981176-1http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/Special:BookSources/978-0-321-53616-7http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/Neil_Campbell_(scientist)http://en.wikipedia.org/wiki/Platelet#cite_note-36http://en.wikipedia.org/wiki/Platelet#cite_note-pmid16537051-35http://en.wikipedia.org/wiki/Pediatrichttp://en.wikipedia.org/wiki/Neonatal


13/15

8. McAleer JP, Sharma S, Kaplan EM, Persich G (2006). "Use of autologous plateletconcentrate in a nonhealing lower extremity wound".Adv Skin Wound Care19 (7): 354

63.doi:10.1097/00129334-200609000-00010.PMID16943701.

9. Driver VR, Hanft J, Fylling CP, Beriou JM (2006). "A prospective, randomized, controlledtrial of autologous platelet-rich plasma gel for the treatment of diabetic foot ulcers".Ostomy Wound Manage52 (6): 6870, 72, 74 passim.PMID16799184.

10. Kroll, M., J. Hellums, et al. (1996). "Platelets and shear stress." Blood 88(5): 1525-154111. Cattaneo M (2011) Molecular defects of the platelet P2 receptors.Purinergic Signal12. Movat H.Z et al. (1965)."Platelet Phagocytosis and Aggregation".Journal of Cell Biology

27 (3): 531543.doi:10.1083/jcb.27.3.531.PMC2106759.PMID4957257.

Weyrich AS, Zimmerman GA (2004). "Platelets: signaling cells in the immune

continuum". Trends Immunol. 25 (9): 48995. doi:10.1016/j.it.2004.07.003.

PMID15324742.

13. Wagner D.D. et al. (2003). "Platelets in inflammation and thrombosis". Thromb VascBiol23: 21317.doi:10.1161/01.ATV.0000095974.95122.EC.

14. Diacovo T.G. et al. (1996). "Platelet-mediated lymphocyte delivery to high endothelialvenules". Science273 (5272): 2525.doi:10.1126/science.273.5272.252.PMID8662511.

15. Iannacone M. et al. (2005). "Platelets mediate cytotoxic T lymphocyte-induced liverdamage". Nat Med 11 (11): 11679. doi:10.1038/nm1317. PMC2908083.

PMID16258538.

16. Parveen June Kumar, Michael L. Clark (2005). "8". Clinical Medicine (6th ed.). ElsevierSaunders. p. 469.ISBN0-7020-2763-4.

17. van Veen JJ, Nokes TJ, Makris M. (2010). "The risk of spinal haematoma followingneuraxial anaesthesia or lumbar puncture in thrombocytopenic individuals.". Br J

Haematol148 (1): 1525.PMID19775301.

18. (2005). "Platelet Functionafter Taking Ibuprofen for 1 Week". Annals of internal medicine 142 (7): I54.

PMID15809457.

19. Rao, GH; Johnson, GG; Reddy, KR; White, JG (1983). "Ibuprofen protects plateletcyclooxygenase from irreversible inhibition by aspirin".Arteriosclerosis (Dallas, Tex.) 3

(4): 3838.PMID6411052. Retrieved 2008-08-26.
http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1097%2F00129334-200609000-00010http://dx.doi.org/10.1097%2F00129334-200609000-00010http://dx.doi.org/10.1097%2F00129334-200609000-00010http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/16943701http://www.ncbi.nlm.nih.gov/pubmed/16943701http://www.ncbi.nlm.nih.gov/pubmed/16943701http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/16799184http://www.ncbi.nlm.nih.gov/pubmed/16799184http://www.ncbi.nlm.nih.gov/pubmed/16799184http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106759http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106759http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106759http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1083%2Fjcb.27.3.531http://dx.doi.org/10.1083%2Fjcb.27.3.531http://dx.doi.org/10.1083%2Fjcb.27.3.531http://en.wikipedia.org/wiki/PubMed_Centralhttp://en.wikipedia.org/wiki/PubMed_Centralhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106759http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106759http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106759http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/4957257http://www.ncbi.nlm.nih.gov/pubmed/4957257http://www.ncbi.nlm.nih.gov/pubmed/4957257http://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1016%2Fj.it.2004.07.003http://dx.doi.org/10.1016%2Fj.it.2004.07.003http://dx.doi.org/10.1016%2Fj.it.2004.07.003http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/15324742http://www.ncbi.nlm.nih.gov/pubmed/15324742http://www.ncbi.nlm.nih.gov/pubmed/15324742http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1161%2F01.ATV.0000095974.95122.EChttp://dx.doi.org/10.1161%2F01.ATV.0000095974.95122.EChttp://dx.doi.org/10.1161%2F01.ATV.0000095974.95122.EChttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1126%2Fscience.273.5272.252http://dx.doi.org/10.1126%2Fscience.273.5272.252http://dx.doi.org/10.1126%2Fscience.273.5272.252http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/8662511http://www.ncbi.nlm.nih.gov/pubmed/8662511http://www.ncbi.nlm.nih.gov/pubmed/8662511http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1038%2Fnm1317http://dx.doi.org/10.1038%2Fnm1317http://dx.doi.org/10.1038%2Fnm1317http://en.wikipedia.org/wiki/PubMed_Centralhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/16258538http://www.ncbi.nlm.nih.gov/pubmed/16258538http://www.ncbi.nlm.nih.gov/pubmed/16258538http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/Special:BookSources/0-7020-2763-4http://en.wikipedia.org/wiki/Special:BookSources/0-7020-2763-4http://en.wikipedia.org/wiki/Special:BookSources/0-7020-2763-4http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/19775301http://www.ncbi.nlm.nih.gov/pubmed/19775301http://www.ncbi.nlm.nih.gov/pubmed/19775301http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/15809457http://www.ncbi.nlm.nih.gov/pubmed/15809457http://www.ncbi.nlm.nih.gov/pubmed/15809457http://atvb.ahajournals.org/cgi/content/abstract/3/4/383http://atvb.ahajournals.org/cgi/content/abstract/3/4/383http://atvb.ahajournals.org/cgi/content/abstract/3/4/383http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/6411052http://www.ncbi.nlm.nih.gov/pubmed/6411052http://www.ncbi.nlm.nih.gov/pubmed/6411052http://www.ncbi.nlm.nih.gov/pubmed/6411052http://en.wikipedia.org/wiki/PubMed_Identifierhttp://atvb.ahajournals.org/cgi/content/abstract/3/4/383http://atvb.ahajournals.org/cgi/content/abstract/3/4/383http://www.ncbi.nlm.nih.gov/pubmed/15809457http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/19775301http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/Special:BookSources/0-7020-2763-4http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://www.ncbi.nlm.nih.gov/pubmed/16258538http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://en.wikipedia.org/wiki/PubMed_Centralhttp://dx.doi.org/10.1038%2Fnm1317http://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908083http://www.ncbi.nlm.nih.gov/pubmed/8662511http://en.wikipedia.org/wiki/PubMed_Identifierhttp://dx.doi.org/10.1126%2Fscience.273.5272.252http://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1161%2F01.ATV.0000095974.95122.EChttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.ncbi.nlm.nih.gov/pubmed/15324742http://en.wikipedia.org/wiki/PubMed_Identifierhttp://dx.doi.org/10.1016%2Fj.it.2004.07.003http://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.ncbi.nlm.nih.gov/pubmed/4957257http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106759http://en.wikipedia.org/wiki/PubMed_Centralhttp://dx.doi.org/10.1083%2Fjcb.27.3.531http://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106759http://www.ncbi.nlm.nih.gov/pubmed/16799184http://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/16943701http://en.wikipedia.org/wiki/PubMed_Identifierhttp://dx.doi.org/10.1097%2F00129334-200609000-00010http://en.wikipedia.org/wiki/Digital_object_identifier


14/15

20. Erpenbeck L, Schn MP (2010)."Deadly allies: the fatal interplay between platelets andmetastasizing cancer cells". Blood 115 (17): 342736. doi:10.1182/blood-2009-10-

247296.PMC2867258.PMID20194899.

21. Pleass RJ (2009). "Platelet power: sticky problems for sticky parasites?". TrendsParasitol.25 (7): 2969.doi:10.1016/j.pt.2009.04.002.PMC3116138.PMID19539528.

22. Kornerup KN, Page CP. The role of platelets in the pathophysiology of asthma. Platelets.2007 Aug 18(5):319-28.

23. http://www.ncbi.nlm.nih.gov/pubmed/17654302 24. Laidlaw TM, Kidder MS, Bhattacharyya N, Xing W, Shen S, Milne GL, Castells MC, Chhay

H, Boyce JA. Cysteinyl leukotriene overproduction in aspirin exacerbated respiratory

disease is driven by platelet-adherent leukocytes. Blood. 2012 Jan 18.

25. http://www.ncbi.nlm.nih.gov/pubmed/22262771 26. Brewer DB (2006). "Max Schultze (1865), G. Bizzozero (1882) and the discovery of the

platelet". Br. J. Haematol. 133 (3): 2518. doi:10.1111/j.1365-2141.2006.06036.x.

PMID16643426.

27. Schultze M (1865). "Ein heizbarer Objecttisch und seine Verwendung beiUntersuchungen des Blutes".Arch Mikrosc Anat1 (1): 142.doi:10.1007/BF02961404.

28. Bizzozero, J. (1882). "ber einen neuen Forrnbestandteil des Blutes und dessen Rollebei der Thrombose und Blutgerinnung".Arch Pathol Anat Phys Klin Med90 (2): 261332.

doi:10.1007/BF01931360.

29. American Association of Blood Banks Standards for Blood Banks and TransfusionServices, Bethesda, MD: 22rd ed, AABB, 2003, Section 5.1.5.1.

30. Hogman, C. F. (1992). "New trends in the preparation and storage of platelets".Transfusion32 (1): 36.doi:10.1046/j.1537-2995.1992.32192116428.x.PMID1731433.

31. Ruane, P.H. et al. (2004). "Photochemical Inactivation of Selected Viruses and Bacteriain Platelet Concentrates Using Riboflavin and Light". Transfusion 44 (6): 877885.

doi:10.1111/j.1537-2995.2004.03355.x.PMID15157255.

32. Perez-Pujol, S. et al. (2005). "Effects of a New Pathogen-Reduction Technology (MirasolPRT) on Functional Aspects of Platelet Concentrates". Transfusion 45 (6): 911919.

doi:10.1111/j.1537-2995.2005.04350.x.PMID15934989.

33. AABB Standards for Blood Banks and Transfusion Services 26th Edition Bethesda, MD:AABB, 2009.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867258http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867258http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867258http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867258http://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1182%2Fblood-2009-10-247296http://dx.doi.org/10.1182%2Fblood-2009-10-247296http://dx.doi.org/10.1182%2Fblood-2009-10-247296http://dx.doi.org/10.1182%2Fblood-2009-10-247296http://en.wikipedia.org/wiki/PubMed_Centralhttp://en.wikipedia.org/wiki/PubMed_Centralhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867258http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867258http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867258http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubmed/20194899http://www.ncbi.nlm.nih.gov/pubmed/20194899http://www.ncbi.nlm.nih.gov/pubmed/20194899http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116138http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116138http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://dx.doi.org/10.1016%2Fj.pt.2009.04.002http://dx.doi.org/10.1016%2Fj.pt.2009.04.002http://dx.doi.org/10.1016%2Fj.pt.2009.04.002http://en.wikipedia.org/wiki/PubMed_Centralhttp://en.wikipedia.org/wiki/PubMed_Centralhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116138http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116138http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116138http://en.wikipedia.org/wiki/PubMed_Identifierhttp://en.wikipedia.org/wiki/PubMed_Identifierhttp://www.ncbi.nlm.nih.gov/pubm

Platelets Information

Documents

Transcript of Platelets Information