Blood clotting: Difference between revisions
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Blood is fluid in nature and is essential for the transport of nutrients including oxygen round the body through the circulatory system by the aid of the | [[Blood|Blood]] is fluid in nature and is essential for the transport of nutrients including oxygen round the body through the circulatory system by the aid of the heart and blood vessels.The rupture of these blood vessels can be catastrophic and the body naturally solves this by the process of Hemostasis. Hemostasis helps prevent blood loss by three (3) main stages namely:<ref>Silverton D. (2010)Human Physiology;An Integrated Approach, 5th Edition, San Francisco; Pearson Education, Inc.</ref> | ||
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'''<u>Platelet Aggregation</u>''' | '''<u>Platelet Aggregation</u>''' | ||
Normally, the endothelium of blood vessels shield the circuating blood from the collagen matrix but when vessel is damaged, the collagen matrix is exposed and this results in the interaction of platelet with exposed collagen.The adhesion of a platelet with collagen initiates a positive feedback mechanism where signalling molecules released by activated activated platelet recruit other platelet molecules promoting platelet aggregation that forms a loose platelet plug in the hole.<ref>Baron, W.F. and Boulpaep,E.L.,(2009) Medical Physiology:A cellular and Molecular Approach,2nd Edition,philadelphia;SAUNDERS ELSEVIER</ref> | Normally, the endothelium of blood vessels shield the circuating blood from the collagen matrix but when vessel is damaged, the collagen matrix is exposed and this results in the interaction of [[Platelets|platelet]] with exposed collagen.The adhesion of a platelet with collagen initiates a positive feedback mechanism where signalling molecules released by activated activated platelet recruit other platelet molecules promoting platelet aggregation that forms a loose platelet plug in the hole.<ref>Baron, W.F. and Boulpaep,E.L.,(2009) Medical Physiology:A cellular and Molecular Approach,2nd Edition,philadelphia;SAUNDERS ELSEVIER</ref> | ||
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It is very important that the body regulates hemostasis properly as it can lead to thrombosis where in excess and hemorrage where there is little hemostasis. | It is very important that the body regulates hemostasis properly as it can lead to thrombosis where in excess and hemorrage where there is little hemostasis. | ||
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=== References === | |||
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Revision as of 19:07, 29 November 2011
Blood is fluid in nature and is essential for the transport of nutrients including oxygen round the body through the circulatory system by the aid of the heart and blood vessels.The rupture of these blood vessels can be catastrophic and the body naturally solves this by the process of Hemostasis. Hemostasis helps prevent blood loss by three (3) main stages namely:[1]
1) Vasoconstriction
2)Platelet Aggregation
3)Coagulation
Vasoconstiction
The blood pressure in the damaged blood vessel decreases when vasoconstrictive paracrines released by the endothelium causes the constriction of the damaged blood vessel
Platelet Aggregation
Normally, the endothelium of blood vessels shield the circuating blood from the collagen matrix but when vessel is damaged, the collagen matrix is exposed and this results in the interaction of platelet with exposed collagen.The adhesion of a platelet with collagen initiates a positive feedback mechanism where signalling molecules released by activated activated platelet recruit other platelet molecules promoting platelet aggregation that forms a loose platelet plug in the hole.[2]
Coagulation
A series of steps leading to the formation of fibrin protein fibre involving different clotting factors such as factor IX,factor III is known as coagulation cascade.it is this fibrin produced that stabilizes the platalet plug which is called 'clot'.
Upon repair of the vessel, the clot is eliminated and digested by an enzyme called plasmin.
It is very important that the body regulates hemostasis properly as it can lead to thrombosis where in excess and hemorrage where there is little hemostasis.