<unk> , also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism of<unk>  involves activation, adhesion and aggregation of platelets, as well as deposition and maturation of fibrin.<unk>  begins almost instantly after an injury to the endothelium lining a blood vessel. Exposure of blood to the subendothelial space initiates two processes: changes in platelets, and the exposure of subendothelial tissue factor to plasma factor VII, which ultimately leads to cross-linked fibrin formation. Platelets immediately form a plug at the site of injury; this is called primary hemostasis. Secondary hemostasis occurs simultaneously: additional<unk>  (clotting) factors beyond factor VII (listed below) respond in a cascade to form fibrin strands, which strengthen the platelet plug. Disorders of<unk>  are disease states which can result in problems with hemorrhage, bruising, or thrombosis.<unk>  is highly conserved throughout biology. In all mammals,<unk>  involves both cellular components (platelets) and proteinaceous components (here,<unk>  factors). The pathway in humans has been the most extensively researched and is the best understood.
Coagulation
Hemostasis
Bone conduction
Sensation 
Thermoregulation
Sensory phenomena
Endocrine system
Gastrointestinal physiology