Why does blood clot outside the body? What is the difference between clotting and clotting of blood?

There are many mechanisms for hemostasis and coagulation when blood is damaged and bleeding, but most of them are related to the role of platelets.

The damaged blood vessels or tissues are in the process of producing some factors, initiating the endogenous and exogenous blood coagulation system, and under the combined action of different factors released by platelets, a series of enzymatic biochemical chain reactions are completed within a few minutes, and finally the soluble fibrinogen in the plasma is converted into insoluble fibrin. The molecular weight of fibrinogen is about 340,000, and several peptide chains are observed to form a four-order structure of spiral coiling under electron microscopy, which is clumpy as a whole. Fibrin is elongated filamentous and intertwined into a web that traps blood cells and forms jelly-like blood clots.

In the body, because the walls of blood vessels are smooth, coagulation does not occur, and when an impact causes a blood vessel to rupture, it will coagulate, forming congestion.

Simply because there are platelets, which automatically clot in the wound when a blood vessel ruptures.

Because of the presence of platelets, it has the effect of clotting blood.

Under the action of coagulation factors, fibrinogen becomes filamentous and mixes with red blood cells to achieve coagulation.

Biology says: because there are a lot of platelets in the blood, the cause of platelets makes it coagulate! If there are no platelets, people will bleed to death if they have wounds.

Platelets are problematic, but there are people who don't coagulate. I forgot what the disease was.

Because there is a cause of platelets.

First, the reference is different.

1. Blood agglutination: When some heterotypic blood in the human body meets, the serum condensin in the blood of one party will cause the corresponding condensation on the surface of the blood cells in the blood of the other party to have an immune response.

2. Blood coagulation: the process by which blood changes from a flowing liquid state to a jelly-like clot that cannot flow.

Second, the main body of the reaction is different.

1. Blood agglutination: It is the serum immune response that may occur when blood of different blood types meet.

2. Blood coagulation: It is the enzymatic reaction of a person's blood under the action of coagulation factors in one's own blood.

Third, the principle is different.

1. Blood agglutination: When the human blood vessel is ruptured or the blood encounters a rough surface, the coagulation mechanism in the blood is activated, and the platelets and fibrin in the serum coagulate together on the wound surface to prevent the blood from continuing to flow out. If the body lacks platelets or a clotting factor, the blood will not clot.

2. Blood coagulation: fibrinogen in plasma is transformed into insoluble fibrin. The multimeric fibrin is intertwined into a web that traps many blood cells to form blood clots.

1 2 hours after the blood clotting process, the blood clot undergoes contraction under the action of platelets and precipitates a yellowish liquid.

Clotting is the phenomenon in which red blood cells clot together when two different pieces of blood are mixed together. Coagulation, on the other hand, refers to the conversion of fibrinogen in the plasma into fibrin, which traps red blood cells together to form a blood clot surrounded by serum.

Summary. Blood does not clot in the following situations.

1. When suffering from hemophilia, resulting in abnormal coagulation factors, ** wounds often cause blood flow to stop.

2. When suffering from aplastic anemia, acute upper respiratory tract infection, hepatosplenomegaly, myelofibrosis, rheumatism and immune diseases, or due to radiotherapy, chemotherapy, drug injury, etc., resulting in thrombocytopenia, abnormal coagulation function, and blood non-coagulation symptoms will also appear.

3. In addition, when liver disease is severe, it will lead to a lack of coagulation factors in the body, and blood will not coagulate.

Under what circumstances does the blood not clot.

Hello, happy to answer your questions.

Blood does not clot in the following situations. 1. When suffering from hemophilia, resulting in abnormal coagulation blind factor, ** wounds often lead to more than 2 aplastic anemia, acute upper respiratory tract infection, hepatosplenomegaly, myelofibrosis, rheumatism and other diseases, or because of radiotherapy, chemotherapy, drug grinding and other injuries, resulting in thrombocytopenia, coagulation function isolary, and there will also be symptoms of blood non-coagulation. 3. In addition, when liver disease is severe, it will lead to a lack of coagulation factors in the body, and blood will not coagulate.

Blood does not coagulate may also be due to the lack of the body's life-sustaining eggplant lisine, we must pay attention to the hygiene around the wound to avoid infection, if the wound injury is more serious, you should also inject tetanus vaccine, it is recommended to choose to use some oral drugs to promote blood coagulation, and usually pay attention to rest.

Factor Xa is a serine protease that has the ability to break peptide bonds in macromolecule proteins, making it a small molecule protein.

In mammals, serine proteases play an important role, especially in the digestive, coagulation, and complement systems.

Mechanism of action: Through the adjacent amino acid residue chain, the serine residue is activated in the active center, and the activated hydroxyl group undergoes a nucleophilic reaction with the carbon atom of the peptide bond. After the peptide bond is broken, the carbon on the acyl group is esterified, the nitrogen end of the peptide bond is released freely, and the hydrolysis reaction releases the carbon end product attached to the enzyme. The reaction is complete.

The main reasons are: (1) the normal intima of the heart and blood vessels is smooth, which does not cause the destruction of platelets in Pichai Sheng; (2) There are anticoagulant substances in the blood, such as heparin, which is a more important anticoagulant produced in the body. It can inhibit the conversion of prothrombin to thrombin, thereby inhibiting fibrinogen from forming fibrin; (3) There is also a substance in the plasma that dissolves the formed fibrin and dissolves the fibrin formed in the blood vessel at any time.

If you have solved your doubts, please click Satisfied in the upper right corner, thank you.

Children love to play, and if they are not careful, they will be scratched and bleeding, and attentive friends will find that the blood from the wound will soon coagulate automatically. So why does blood clot on its own? Why blood doesn't clot in the human body.

What is the reason for this? I believe that many friends don't know much, so let's find out with me.

Wherever it breaks, there will be red blood oozing out, and this oozing blood will soon clot into a ball and block the scratch - this is the result of platelets resuscitating the wound.

There are a lot of platelets living in the blood, and as soon as it flows out of the blood vessels, it immediately "crushes the bones", and the platelet factor and plasma coagulation progen, with the help of calcium ions, interact to form coagulation activase; Prothrombin in the blood is converted into a small amount of thrombin under the action of calcium ions and thromboactivating enzymes;

Fibrinogen in plasma is present in thrombin and platelet factor'Under the action, it becomes a reticulated solid fibrin. Fibrin is the "cement" of the human body, which will quickly solidify and coagulate into slender and long fibers. These fibers are then intertwined and overlapped with each other, and finally the "breach" is blocked, so that the blood does not flow out.

After a few days, the wound curdled into a hard crust.