HAEMORRHAGIC

The fibrinogen molecule is 30 times as long as it is broad. This asymmetry is responsible for the increased viscosity of the blood, and the increased rouleaux formation of red cells. Increased sedimentation rate of red cells of the blood occurs when there is increased amount of fibrinogen in the plasma. Fibrinogen is formed...
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Plasma factor defects. Deficiency of accelerators of prothrombin activity gives rise to haemophilia in which the coagulation time is prolonged. Haemophilia is inherited as a sex-linked recessive character transmitted from affected males to unaffected female conductors. Haemorrhage occurs either spontaneously or from slight trauma. Subcutaneous or intramuscular haemorrhage and bleeding from the mucous membrane...
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Prothrombin defects – congenitial (Haemorrhagic disease of the new-born) This is due to an exaggeration of the temporary physiological fall of prothrombin that occurs between the 1 st and 5th day of life, occurring in about 1% of new-born infants. At birth the baby has no reserve of vitamin K and its formation by...
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A study of the normal blood coagulation process reveals a two-stage reaction in which four main concepts about the chemistry of blood coagulation are integrated in proper order. The first stage of the reaction, in which the prothrombin of plasma is activated to thrombin represents a co-ordination of the first two concepts, viz., (1)...
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Platelets are derived from megakaryocytes of bone marrow. These are oval and thin, non-nucleated discs 2 to 3 microns in diameter. Normal count – 250,000 – 500,000 per c.mm. of blood. Agglutination of platelets is favoured by substances exuded by injured tissue, and inhibited in vitro, by anticoagulants like citrate or oxalate, or in...
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The arteries, veins and capillaries, all posses the property of contractility on injury. In small vessels with minute ruptures, local vasoconstriction together with the deposition of platelets from flowing blood on the vessel wound may successfully seal off the gaps without the help of blood coagulation. But, when a large vessel is ruptured, these...
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The conditions which come under this group can be classified under four heads. I. Congenial. Hereditary haemorrhagic telangiectasis, hereditary haemorrhagic thrombasthenia, Glanzmann’s and von Willebrand’s disease II. Infective . Toxic : Haemorrhagic scarlet fever, measles. Enbolic : Meningococcal or typhoid septicaemia, Endocarditis III. Nutritional. Vitamin C deficiency. IV. Allergic. Henoch-Schonlein purpuras, focal infection, serum...
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The elasticity and resistance of the tissues surrounding the blood vessels protect them and resist the escape of the blood from the site of injury and help in closing the gap in the vessel. Therefore, when this tissue support is lacking as in the substance of the brain, the loose areolar tissue round the...
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Those pathological conditions of the body which allow to escape from the blood vessels, spontaneously or as the result of trauma unable in itself to cause haemorrhage in a normal person, are known as haemorrhagic disorders. There must be some defect in either one or two or all the three normal mechanisms of haemostatis...
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