Gesamthämostase

GesamtHämostase, also known as total hemostasis, refers to the complex process by which blood vessels are sealed off to prevent excessive bleeding. This process involves a series of interconnected steps that work together to achieve hemostasis. The initial response to injury involves the formation of a platelet plug, which is a temporary seal created by the aggregation of platelets at the site of injury. This plug is stabilized by the release of various factors from activated platelets, such as ADP and thromboxane A2, which recruit additional platelets to the site.

Simultaneously, the coagulation cascade is activated, leading to the formation of a fibrin clot. This cascade begins with the exposure of tissue factor (TF) on the injured vessel wall, which activates factor VII. The activated factor VII then activates factor X, which in turn activates factor IX. The activated factor IX then activates factor X, leading to the formation of prothrombinase, a complex of factors IXa, Xa, and Va. Prothrombinase activates prothrombin to thrombin, which converts fibrinogen to fibrin, forming the fibrin clot.

The fibrin clot provides a stable matrix for the platelet plug, further reinforcing the seal on the injured vessel. Additionally, the release of various growth factors and cytokines from activated platelets and other cells at the site of injury promotes the recruitment and activation of additional cells, such as endothelial cells and smooth muscle cells, which contribute to the repair of the injured vessel.

Overall, GesamtHämostase is a highly regulated and coordinated process that involves the interplay of platelets, the coagulation cascade, and various growth factors and cytokines. This process is essential for maintaining normal hemostasis and preventing excessive bleeding.