Coagulation and anticoagulant mechanism: Characteristics of the body

Without the coagulation process, our bodies (and the circulatory organism in general) cannot survive. But without the anticoagulation process, coagulation will spread from one blood vessel to another and the circulation will stop. Coagulation system and anticoagulant mechanism is a closed system - these are two very unique processes that have many protective properties.

Coagulation and anticoagulation

Coagulation is a phenomenon in which blood from the liquid changes to a solid body. There are always dozens of substances in blood plasma involved in blood clotting. But the blood in the veins will never coagulate, but when removed from the bloodstream, it immediately cools. So far, more than 30 different substances in the blood and organs have been known to affect blood clotting. These are substances that cause blood clotting and anticoagulants. Coagulated blood is dependent on the balance between these two groups of substances.

Coagulation and anticoagulation is a very complicated process, both of these phenomena occur, parallel progress, but ultimately to stop bleeding, or avoid rampant coagulation once it has formed enough .

Can be taken for example: When we cut fruits, accidentally cut off the hand, immediately the injury has vasoconstriction due to neural reflexes. The larger the lesion, the greater the contraction level of the vasculature, enabling the formation of platelet nodes and blood clots that stop bleeding. The natural coagulation process involves a series of reactions and reactions that at each stage must be made faster than its destruction, if desired for later stages of coagulation. can proceed. When the balance between the two processes deviates to one side, there will be no blood clotting, or an overcrowding of blood.

Blood coagulation diagram

The role of platelets

Platelets are derived from bone marrow. It is a non-nuclear cell, a thin disc, 2-3 microns in diameter, negatively charged. The normal number of platelets in peripheral blood is 150,000 - 300,000 / mm ³ and can be reduced or reduced in a narrow range thanks to a special regulatory mechanism. The life of platelets is only 8-12 days, it is also 'mature' and ' aged ' before being destroyed naturally and there is another platelet class instead. Thrombocytopenia in terms of quantity or quality will cause bleeding pathogenesis.

Normally platelets float freely according to blood flow. When the blood vessel breaks, the collagen fibers below the epithelial layer are exposed and the platelets will stick to the rupture circuit (due to the non-platelet-deflated non-platonic wall). Next, the circulating platelets will come to agglomerate there and bring together the 3rd, 4th platelet aggregation . until the platelet node is formed (also called the hemostatic Hayem). closed the injury.

And dozens of other factors

Want to clot blood, fibrin must appear. If the experiment packs a lump of secretions (pigs, chickens, ducks .) into several layers of bucket cloth, squeeze the blood in the lumps into the NaCl 0.9% salt solution; continue dipping the pack into salt solution and squeeze it over and over again. Finally opened, there was only a bunch of white tangled strands called fibrin in the pack. But to get fibrin, dozens of previous stitches must be activated. Whenever a certain element is found to be responsible for one stage, one will give a name. Dozens of factors are connected and carry names according to each author, so complex. Eventually, it was reunited in 1959 during an international conference on blood coagulation, unifying the rule of naming coagulation elements in Roman numerals (with 12 coagulation factors).

Coagulation factors have enough face in the blood stream and mostly in the form of inactive precursors. When an element is activated, it will lead to the activation of other elements in an automatic chain reaction that results in the formation of a fibrin network. And red blood cells are 'tied' by fibrin fibers - it's a blood clot. After the blood clot has formed, platelets that secrete yeast (retractolysine) cause the volume of blood clots to go away, and at the same time to produce serum.

On the other hand, there is an euglobin in the plasma protein called plasminogen. This substance becomes activated when plasmin is a very strong protein digestive enzyme. Plasmin destroys fibrin fibers as well as other coagulation factors such as fibrinogen, factor II, V, VIII, and XII. When a blood clot forms, most plasminogen joins the blood clot with other plasma proteins. Every time plasmin is formed in a blood clot, it can dissolve blood clots and destroy a lot of clotting factors that reduce blood clotting. It has been found that blood clots for some reason are formed in blood vessels that can also be dissolved by blood plasminogen activators. This has a positive meaning, it clears tiny blood clots that form in the vein, thus preventing embolism, preventing the formation of blood clots, and protecting the smooth flow of blood vessels. .

Diseases caused by hard blood

Platelets: Low blood platelets when less than 100,000 / mm ^{3 of} blood are markedly reduced and cause haemorrhage. Thrombocytopenia may be congenital like werlhoff disease, but most cases are due to myelosuppression, or because the platelet life is shortened. In addition, there are cases of impaired platelet function although the number does not decrease. The lack of platelets shown by the measurement of bleeding time will last. When thrombocytopenia causes blood clotting and blood clots to not coagulate, vascular constriction is poor when hemostatic Or the phenomenon of bleeding under the skin and mucosa.

Hemophiliosis: If factor VIII is lacking, hemophiliemia is a spontaneous bleeding, or due to very small causes. Hemorrhage due to minor impact, may not bleed even dangerous to life because of a broken hand, extracted teeth . Often death due to anemia or prolonged blood loss. This is a congenital, double-inherited disease associated with sex because the disease gene is located in the sex chromosome X. Only a male is ill, and the daughter carries a genetic predisposition. Treatment by injection of factor VIII, fresh blood transfusion (fresh serum). Missing factor IX is B. hemophiliemia. Song hemophili A is more severe and common in Vietnamese children.

In addition, people with severe hepatic impairment will lead to poor production of clotting factors, such as pre-trombin, fibrin production . Lack of vitamin K is a vitamin that plays a role in the production of pre-trombin also makes blood hard to east.

DoctorVu Huong Van