The concept of coagulation comes from the Latin coagulatio. It is about the act and result of clotting – what happens when a liquid, especially blood, thickens or solidifies.
Coagulation, therefore, involves the transformation of a fluid into a thick, pasty substance. This process, when it involves the blood, has important consequences for the body.
As clotting occurs, the blood loses its liquid state until a clot develops. This allows, for example, blood to stop flowing through a broken vessel.
Platelets are involved in coagulation, which are oval cells – lacking nuclei – found in the blood of vertebrate animals. The process also takes place thanks to proteins in the blood called fibrins. When a blood vessel is damaged, platelets first create a plug to stop blood loss. This process is known as primary hemostasis. In parallel, various enzymatic reactions allow the formation of fibrin, which reinforces the plug made by platelets. This property is called secondary hemostasis.
Proteins that are found in the blood and act directly on the formation of clots are known as clotting factors. There are thirteen, each with a Roman numeral that identifies and orders it. Clotting factors require activation cofactors, such as phospholipids and calcium. Regarding their function, they are essential to generate coagulation and, therefore, if they are not present, the body can suffer serious bleeding problems.
There are various imbalances that affect coagulation and can cause bruising to spontaneous bleeding or thrombosis (a clot blocking a blood vessel). There are also diseases related to clotting problems.
One of them is hemophilia, a genetic disorder linked to the X chromosome that prevents proper blood clotting. A hemophilic patient may suffer spontaneous bleeding that is prolonged and can atrophy his joints. Three types of hemophilia can be seen: A, if coagulation factor VIII is in deficit; the B, if the deficit occurs in factor IX; the C, with a deficit in factor XI.
Hemophilia A participates in the activation of the process that transforms prothrombin into thrombin, and it is estimated that it occurs in one in every five thousand men. The incidence of hemophilia B is lower, one in every 100,000 men, and has a variant called Leyden, which is even less common and with a severity directly proportional to the age of the subject.
The thrombosis, on the other hand, is a blood clot that forms in a blood vessel. One of the most common causes is an acute myocardial infarction, which is referred to in everyday speech as a heart attack or simply a heart attack. After a blood vessel is injured, the body uses platelets and fibrin to create a clot that prevents excessive blood loss.
Of course, clot formation can also occur without the need for injury to the vessels. When a clot breaks loose and begins to move through the body, it is called an embolism. In addition to acute myocardial infarction, other causes of thrombosis are the following:
* an alteration in clotting factors, such as a decrease in protein S or C;
* a disturbance of the blood vessels, such as a traumatic rupture or arteriosclerosis.