13.1 POJA-L4693+4694+4695+4696+4697 Arterial thrombosis (human)
13.1 POJA-L4693+4694+4695+4696+4697
Title: Arterial thrombosis (human)
Description:
(A-E): Survey and details of a mural (parietal) thrombus at increasing magnifications, Haematoxylin-eosin. The vessel wall (1) is covered by a thrombus with a rough undulating surface. Between masses of erythrocytes columns of platelets are present. Agglutinated platelets visible as fine granules are surrounded by fibrin; leukocytes are also found accumulated (3) in the fibrin. Masses of lytic erythrocytes are found between rows of thin fibrin (E). Thrombus (3), intima (1) and upper layer of media (2).
Background: Thrombosis is an intravascular coagulation of blood during life. In areas of endothelial injuries e.g. atherosclerotic plaques generally arterial thromboses begin. From the site of attachment thrombi will grow in retrograde direction. They are firmly adhered to the arterial wall, and are composed of a mesh of platelets, fibrin, erythrocytes and degenerating leukocytes. On cross-sections vague strands of grey fibrin are visible. These occlusive thrombi usually occur in coronary, cerebral and femoral arteries. Pathogenesis: Rupture of a plaque results in exposure of highly thrombogenic subendothelial extracellular matrix proteins (such as collagen, von Willebrand factor) to circulating platelets that become activated and adhere at the site of injury. They release secretory granules recruiting additional platelets to form a haemostatic plug (process of primary haemostasis). Exposure of tissue factor (TF/factor III) a procoagulant produced by the endothelium to circulating factor VII results in the activation of the coagulation cascade, and activation of thrombin (factor IIa) and factor XIII (fibrin stabilising factor). Thrombin converts circulating soluble fibrinogen to fibrin and also induces further platelet recruitment and granule release. Factor XIII cross links fibrin and the result is a solid permanent plug to prevent any further haemorrhage. The plug is composed of a cross-linked platelet-rich fibrin clot, the key process in acute arterial thrombosis.
Keywords/Mesh: cardiovascular system, vascularisation, artery, thrombosis, fibrin, platelet, histology, POJA collection
Title: Arterial thrombosis (human)
Description:
(A-E): Survey and details of a mural (parietal) thrombus at increasing magnifications, Haematoxylin-eosin. The vessel wall (1) is covered by a thrombus with a rough undulating surface. Between masses of erythrocytes columns of platelets are present. Agglutinated platelets visible as fine granules are surrounded by fibrin; leukocytes are also found accumulated (3) in the fibrin. Masses of lytic erythrocytes are found between rows of thin fibrin (E). Thrombus (3), intima (1) and upper layer of media (2).
Background: Thrombosis is an intravascular coagulation of blood during life. In areas of endothelial injuries e.g. atherosclerotic plaques generally arterial thromboses begin. From the site of attachment thrombi will grow in retrograde direction. They are firmly adhered to the arterial wall, and are composed of a mesh of platelets, fibrin, erythrocytes and degenerating leukocytes. On cross-sections vague strands of grey fibrin are visible. These occlusive thrombi usually occur in coronary, cerebral and femoral arteries. Pathogenesis: Rupture of a plaque results in exposure of highly thrombogenic subendothelial extracellular matrix proteins (such as collagen, von Willebrand factor) to circulating platelets that become activated and adhere at the site of injury. They release secretory granules recruiting additional platelets to form a haemostatic plug (process of primary haemostasis). Exposure of tissue factor (TF/factor III) a procoagulant produced by the endothelium to circulating factor VII results in the activation of the coagulation cascade, and activation of thrombin (factor IIa) and factor XIII (fibrin stabilising factor). Thrombin converts circulating soluble fibrinogen to fibrin and also induces further platelet recruitment and granule release. Factor XIII cross links fibrin and the result is a solid permanent plug to prevent any further haemorrhage. The plug is composed of a cross-linked platelet-rich fibrin clot, the key process in acute arterial thrombosis.
Keywords/Mesh: cardiovascular system, vascularisation, artery, thrombosis, fibrin, platelet, histology, POJA collection