Coagulation blood

These basic chemical reactions occur when blood clots (the Fuld-Mora-witz hypothesis). However, the blood clot is a complex structure derived from the blood, in which cells and fluid matrix are held together and to the wall of the container by fibres of the protein, fibrin, together with disintegrated platelets. The rate at which sufficient thrombin is formed to provide an 

By use of suitable factor preparations to modify the coagulation time, a great variety of tests has been developed. These have been particularly 

Prothrombin activity (=source of thrombin) Ac-globulin activity 1 Proconvertin activity Activity corrective in haemophilia A Activity corrective in haemophilia B Activity corrective in haemophilia C Activity corrective in SPCA deficiency Activity corrective in Hageman trait 

The majority of studies have been based on the measurement of the clotting time or coagulation time. However, there are many standard methods of measuring this and since they measure separate and significant parameters, it is essential to identify the type of determination used. 

The most common tests are (1) Clotting time of whole blood-, (2) clotting time of whole blood collected and measured in silicone-, (3) prothrombin time Quick)—clotting time of recalcified plasma with added thromboplastin (tissue extract) (4) plasma time Howell)—clotting time of recalcified plasma  

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R. G. Macfadane, in R. Biggs, ed.. Human Blood Coagulation, Haemostasis and Thrombosis, 2nd ed., Blackwell Scientific PubHcations, Oxford, 1976, pp. 1-31. 

The calcium ion, necessary for blood-clot formation, stimulates release of bloodclotting factors from platelets (see Blood, coagulants and anticoagulants) (25). Neuromuscular excitabihty also depends on the relative concentrations of Na", Ca ", Mg ", and (26). Upon a decrease in... 

A contusion is an injury to soft tissue in which the skin is not penetrated, but swelling of broken blood vessels causes a bmise. The bmise is caused by a blow of excessive force to muscle, tendon, or ligament tissue. A bmise, also known as a hematoma, is caused when blood coagulates around the injury causing swelling and discoloring skin. Most contusions are mild and respond well to rest, ice, compression, and elevation of the injured area. 

The hemorrhagic diathesis in patients with coagulation disorders is because of either an abnormaUty of one or more plasma proteins and/or platelets necessary for normal blood coagulation or the spontaneous presence of a circulating anticoagulant. Specific laboratory techniques are required for the precise identification of these disorders. 

Dismption of the endothehal surface of blood vessels expose coUagen fibers and connective tissue. These provide surfaces that promote platelet adherence, platelet release reaction, and subsequent platelet aggregation. Substances Hberated from the platelets stimulate further platelet aggregation, eg, adenosine diphosphate maintain vasoconstriction, eg, serotonin and participate in blood coagulation, eg, platelet Factors III and IV. In addition, the release reaction modifies platelet membranes in a manner that renders phosphoHpid available for coagulation. The thrombin [9002-04-4] elaborated by the coagulation mechanism is a potent agent in the induction of the platelet release reaction. 

Factors I, II, III, V, VII, VIII, IX, X, XI, XII, and XIII, Protein C, and Protein S are synthesized in the Hver. Factor III is present in many different organs throughout the body. Factor IV is the divalent cation calcium. The concentration of calcium required for normal function of the blood coagulation system is much less than required for normal physiologic function of many organs in the body, eg, myocardium. 

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