Blood vessels are the channels of life, and the human vascular system is a closed circulatory system made up of arteries and veins connected. A single arrangement of blood vessels throughout the body is about 150,000 kilometers long, which can circle the equator four times. The total mileage of blood circulating throughout the body in 24 hours is about 264,000 km, which is more than 20 times longer than the sum of the length of Yangtze River and Yellow River. In such a long pipeline, blood clots are formed at any time, and are constantly inhibited and dissolved.
How is thrombus generated?
Under normal circumstances, the two systems maintain a dynamic balance, so that the blood always remains in a fluid state, circulating back and forth for a long time. Thrombosis in pathological conditions is related to three factors: slow blood flow, hypercoagulable state of blood and damage to endothelial cells of blood vessels. Slow blood flow rate can damage endothelial cells, which in turn can cause local aggregation of platelets and clotting factors. Endothelial cells are strong guardians against thrombosis. When endothelial cells are injured, the fibrin and collagen behind them immediately act evil and summon platelets, the originators of thrombosis, to the local area. Platelet adhesion is the first step in thrombosis. Platelets gather in piles under the action of pathogenic factors, causing local blood flow to form a vortex, and platelets continue to stick together to form coral-like trabeculae. When there is local damage to the blood vessels in the body, various coagulation factors are activated in turn, and the pro-coagulation force is gradually amplified, finally activating thrombin, which has the effect of cross-linking fibrinogen into fibrin, and the fibrin in the blood flow is interspersed on the platelet trabeculae. At this point, a three-dimensional network consisting of platelets forming a large mesh and fibrin forming a small mesh is formed. Most of the flowing red blood cells cannot pass through the mesh and are captured. Platelets, fibrin, and red blood cells interact to form a thrombus.
Depending on the location and thrombus components, thrombus can be broadly classified into the following types.
1.White thrombus
The white thrombus mainly consists of many platelet trabeculae aggregated in a coral shape, with relatively little fibrin and red blood cells.
2.Red thrombus
It occurs after the blood flow is extremely slow or stopped, and it is similar to the in vitro blood clotting process in both mechanism and morphology. The fibrin mesh is filled with blood cells that are distributed as normal blood.
3. Mixed thrombus
A mixed thrombus is formed by alternating white and red thrombi in layers of red and white streaks, often manifesting as a process of continuous thrombus formation. In mitral stenosis and atrial fibrillation, the thrombus formed in the left atrium is a mixed thrombus.
4. Clear thrombus
Mainly composed of fibrin, this thrombus occurs in small vessels of microcirculation and can only be seen under the microscope, so it is also called microthrombus.
Second, how does the normal human body inhibit the formation of thrombus?
The Creator is always so amazing that there are always factors that promote and inhibit any physiological reaction in the human body, and thrombosis is no exception. The forces against clotting include both anticoagulation and fibrinolysis. Activated coagulation factors are most readily cleared from circulation by the liver and reticuloendothelial system. The presence of anticoagulant substances in the blood antithrombin III (ATIII) is a natural anticoagulant, accounting for 70% of all anticoagulant activity, and it binds to thrombin to inactivate important thrombin and other important coagulation factors. Therefore, patients with congenital ATIII deficiency are highly susceptible to thrombus formation. Heparin-like substances secreted by endothelial cells in the body can fight side by side with ATIII and significantly increase the latter’s fighting power.
A certain concentration of fibrinogen is present in the human blood circulation. Normally, fibrinogen patrols only in the blood. Once a thrombus is formed, it comes into play and is activated to become fibrinolytic enzyme when it meets with a fibrin clot, which can dissolve the fibrin from the inside out.
Third, what conditions are prone to thrombosis?
However, once this balance is disrupted for some reason, the coagulation system is enhanced and the blood will coagulate into a “thrombus” and build a “dam” in the blood vessel, making the vessel “river” “obstruction”. These pro-coagulation forces are mainly related to the three main culprits of thrombosis mentioned earlier.
1, slow blood flow: after major surgery, paraplegia and other patients who are bedridden for a long time, lack of exercise, blood flow has become significantly slower.
2, hypercoagulable state: high blood lipids, high blood sugar, smoking, alcoholism, pregnancy, postpartum, tumors, oral contraceptives and other factors can make the blood in a hypercoagulable state.
3, endothelial cell damage: endophthalmitis, polyarteritis nodosa, atherosclerotic ulcer, rheumatic and bacterial endocarditis, myocardial infarction and other patients with local vascular endothelial integrity are severely damaged, very easy to thrombosis.
In addition, platelet increase or platelet viscosity increase can also increase the coagulation of blood, such as pregnancy, postoperative, postpartum, high-fat diet, smoking and other factors to add to the platelet viscosity increase.
Third, the same thrombosis, why is there a world of difference in the consequences?
This is mainly related to the site of thrombus formation, and not much related to the size. As we all know, the heart and the brain are the two most important organs of the human body, and when the rivers of these two organs are blocked, the result is naturally extremely serious. If it happens in the heart, the result will be angina pectoris, myocardial infarction, and more serious sudden death. In the brain, dizziness, headache, coma, paralysis, etc. can occur. Blood clots can occur in the arteries or in the veins. A common type of venous thrombosis occurs in the deep veins of the lower extremities. Once the thrombus is formed, the venous blood return is blocked and the lower limbs become bruised and edematous. The thighs on the side of the thrombosis are often painful and cannot be walked on. Once the thrombus is dislodged from the veins of the lower extremities, it will follow the blood return pathway and enter the right atrium, eventually blocking the pulmonary artery of comparable diameter, resulting in pulmonary infarction, a highly lethal complication. If the thrombosis occurs in non-critical areas, such as superficial veins and spleen, it is mostly a local symptom, but not a life threatening one.
IV. How to prevent thrombosis?
1.Actively search for diseases that cause hypercoagulation and cut off the causes as soon as possible: such as tumor, ATIII deficiency, hyperlipidemia, hyperglycemia, high blood viscosity, etc.
2.Scientific diet: eat less greasy, high cholesterol, high sugar-containing food. Eat more onions, garlic, peppers, string beans, spinach, celery, cucumbers, carrots, apples, grapes, black fungus, etc. Among the diet is worth recommending big is deep-sea fish and deep-sea fish oil. The fat of fish contains polyvalent unsaturated fatty acids that the body cannot synthesize by itself. Prevent blood clotting, dissolve blood clots, can also reduce the bad cholesterol in the blood, while increasing the good cholesterol.
3, sports: exercise can promote blood circulation, make blood thinning, viscosity decreased. Such as doing gymnastics, playing taijiquan, dancing elderly disco, cycling, walking, jogging, swimming, sword dancing, etc.
4, drink more water: drinking more plain water is the simplest and effective way to prevent thrombosis. Normally develop the habit of drinking water, drink 1000-2000 ml of water daily to reduce blood viscosity, which is good for preventing blood clots.