Hemostasis /mechanism or stages
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If you are looking for how hemostasis works (mechanism) or the steps this is achieved (stages), you can read up the following articles. The first one being more authoritative, but more technical.
http://www.merckmanuals.com/professional/sec11/ch134/ch134a.html
http://en.wikipedia.org/wiki/Hemostasis
Hemostasis is the process of stopping bleeding, usually from a damaged blood vessel. It involves a series of complex mechanisms and stages that work together to form a blood clot, prevent further blood loss, and eventually restore the damaged blood vessel.
There are four primary stages of hemostasis:
1. Vascular Spasm: When a blood vessel is injured, the first response is constriction of the vessel walls, known as vascular spasm. This helps reduce blood flow and prevents excessive bleeding.
2. Platelet Plug Formation: Platelets are small cell fragments found in the blood. When a blood vessel is injured, platelets rapidly adhere to the damaged site and aggregate together to form a platelet plug. They release various substances that attract more platelets and help activate clotting factors.
3. Blood Clotting (Coagulation): Coagulation is a complex process that involves a cascade of enzymatic reactions. It leads to the conversion of soluble proteins called clotting factors into a sticky, insoluble protein called fibrin. Fibrin forms a mesh-like network, which traps platelets, red blood cells, and other components to form a stable blood clot.
4. Clot Retraction and Dissolution: Once the clot is formed, it undergoes clot retraction, which involves contraction and squeezing of the clot, making the blood vessel smaller. This helps to further reduce blood loss from the damaged vessel. Over time, a process called fibrinolysis dissolves the clot as the damaged blood vessel heals.
Understanding the mechanism and stages of hemostasis is crucial for medical professionals to diagnose and treat bleeding disorders, as well as develop interventions to prevent excessive clotting or bleeding in various clinical situations.