Clotting mechanism, Biology

Clotting Mechanism

Four substances are necessary for coagulation of blood; prothrombin, thromboplastin, calcium and fibrinogen. Prothrombin gives rise to thrombin, an enzyme. Fibrinogen, prothrombin, and calcium are present in circulating blood. Thromboplastin (a lipid or fat-like compound containing phosphorus) is widely distributed throughout the tissues, the lung and brain being especially rich in this factor. It is absent or present in only small quantities in blood plasma. When blood is shed, thromboplastin is liberated from injured tissue and probably also from the leucocytes of the blood itself. The thromboplastin, acting upon the prothrombin in the presence of calcium in an ionised form, converts, it to active thrombin. Thrombin acts in turn upon the inactive fibrinogen, converting it into insoluble fibrin which is deposited as fine threads to form the framework of the clot. In simplest possible terms the chief factors are summarised in the following scheme:

 

248_Clotting Mechanism.png

Blood does not normally clot in the blood vessels because there is not sufficient free thromboplastin to convert the inactive prothrombin into the active thrombin.

Posted Date: 1/16/2013 12:29:20 AM | Location : United States







Related Discussions:- Clotting mechanism, Assignment Help, Ask Question on Clotting mechanism, Get Answer, Expert's Help, Clotting mechanism Discussions

Write discussion on Clotting mechanism
Your posts are moderated
Related Questions
Q. How Cleaning agents works? Food particles and other debris provide good nutrients for the nlicroorganisms to grow. In fact, the food particles protect microorganisms d

Q. Of which type of defense cell do worm infections stimulate the multiplication? The main leukocytes that generally participate and multiply in the defense against worm infect

What are the benefits of plant-incorporated protectants? Plant-incorporated protectants can be a promising pest management alternative where traditional pesticides may not be a

List the short-term and long-term effects of forest destruction  (a) on hillsides, (b) in the tropics.  (a) Deforestation on hillsides exposes the soil to erosion by rain and l

At the end of the ventricular contraction, maximum arterial pressure is attained and blood flow is most rapid. This is correctly termed the: a) Arterial maximum b) Diastolic

Define measuring body composition- Multiple isotope Dilution? Multiple isotope dilution (Total and extracellular body water): It is based on the principle that certain substanc

Define Half Saturation Test and Full Saturation Test? This test is specific to polysaccharides. The test is used to detect dextrin from starch. The details related to the test

In the year of 1953, Watson and Crick worked out the 3-D structure of DNA, beginning from X-ray diffraction photographs   taken through Wilkins and Franklin. They decreased which D

Q. What are the major types of animal tissue? The major animal cell tissues are the epithelial tissue, the nervous tissue, the connective tissue and the muscle tissue.

How does chewing food help to speed up digestion? Chewing reduces food to portions small sufficient to be swallowed and enhances the surface area of the food for digestive enzy