What is atherosclerosis. Part I
Atherosclerosis is common arterial disease, in which the vessels lose elasticity, and lipid fractions (cholesterol plaques) are delayed on their walls. As the disease progresses, the size of the plaques increases, the structure of these plaques may vary, and the clearance of the vessel becomes less. This leads to a violation of blood flow, and in the future - an organ infarction, which is supplied with blood.
Atherosclerosis is characteristic of all types of arteries, including aortic, coronary arteries, sleepy, as well as the arteries of the limbs and others. The most common effects of atherosclerosis are ischemic heart disease and myocardial infarction. Against the background of atherosclerotic damage of blood vessels, renal failure, stroke, gangrene limbs, and other pathologies may also develop.
Important: bad and good cholesterol. Under cholesterol plaques, they understand the "bad" cholesterol. These are low-density lipoproteins (LDL), in which there are many fats, but little protein. The "good" cholesterol is considered high-density lipoproteins (HDL), which is not dangerous for vessels. Cholesterol is a vital component, which is part of cell membranes and rows of hormones.
There are several species of atherosclerosis depending on the origin and localization. The first parameter atherosclerosis happens:
• Hemodynamic - develops against the background of vascular pathologies, including arterial hypertension. Inflammatory processes on the walls of the vessels attract the cells of the immune system and fat fractions. So plaques are formed, which over time increase in size.
• Metabolic - occurs when metabolism disorders, when the excess number of LDL circulates in the blood. Exact mechanisms for the appearance of atherosclerotic plaques on the background of metabolic disorders are still unknown. Unfavorable factors, in this case, are obesity, diabetes, excessive use of simple carbohydrates and hypodynamia.
• Mixed - develops against the background of hemodynamic and metabolic disorders. It has been established that in most cases, patients we are talking about mixed atherosclerosis when metabolic changes lead to hemodynamic, and they, in turn, worsen exchange processes even more.
Depending on the localization of atherosclerosis, the following types are:
• coronary vessels;
• vessels of the lower extremities;
• brain vessels;
• kidney vessels, liver, pancreas;
• Other vessels.
What Are the Stage Of Atherosclerosis Pathologies?
There are four stages of development of atherosclerosis pathologies:
Stage I - asymptomatic or preclinical. You can identify atherosclerotic changes only with special diagnostic tools.
Stage II - ischemic. The clearance of the arteries is narrowed, because of which the bodies supplied with blood are not allowed nutrients and oxygen. The most noticeable ischemic manifestations in atherosclerosis of the coronary arteries and arteries of the brain.
III Stage - thrombonecriculture. In places of accumulation of cholesterol plasters, blood clots are formed - thrombus. The danger of thrombus is that it can break away from the wall of the artery, and then with a current of blood clog vessels with a smaller diameter. A full blockage of the vessel leads to necrotic changes that require immediate medical intervention.
IV Stage - sclerotic. This is the terminal period of atherosclerosis on which the affected area of the vessel is replaced by the scar. The artery loses elasticity and is not able to perform its functions to ensure uniform blood current.
What are the risk factors of atherosclerosis?
Atherosclerotic changes in vessels, all people are subject to one degree or another. It all depends on when atherosclerosis will lead to serious complications - in 40 years or 80. Consider the main groups of people who risk meeting this problem before the rest:
• People with arterial hypertension. Increased pressure - damaging factor for vessels. In case of damage, an inflammatory process develops, which is the main trigger for the appearance of cholesterol plaques.
• People with metabolic diseases. Violations of lipid metabolism, diabetes, as well as hormonal disorders are the risk factors for the development of atherosclerosis.
• People suffering from obesity. This factor in aggregate with improper nutrition is one of the main atherosclerosis in the development.
• People with a sedentary lifestyle. Physical inactivity impairs blood flow, and also contributes to the development of congestion.
• Other factors. The development of atherosclerosis also contributes infectious diseases (inflammation sources), improper nutrition, stress, hereditary factors, as well as increased blood viscosity.
Important: atherosclerosis and cholesterol.
Until the end of the last century, doctors believed that between the use of animal food (which contains cholesterol) and atherosclerosis there is a direct connection. It was believed that the more cholesterol to eat, the higher the probability of the disease. However, the development of atherosclerosis of cholesterol alone is not enough. If the arteries walls are not damaged, then how much cholesterol does not circulate in the blood, atherosclerosis will not. Besides, the main amount of cholesterol is synthesized in the liver, therefore, the cholesterol introduced from the outside does not have a negative effect.
What Causes atherosclerosis
Until now, the exact causes of atherosclerosis are unknown. Copying information about the disease has shown that the main cause of atherosclerosis is damage to the inner wall of the vessel, for example, at high pressure. An indirect confirmation of this theory is the fact that the most often atherosclerotic changes affect the places of branching the arteries, where the maximum blood pressure is.
How Hypertension Cause Atherosclerosis
In case of damage to the walls of vessels, an inflammatory process develops. Also, the reinforced blood flow at elevated pressure contributes to the products in the vessel walls of the adhesion molecules. They attract immune cells, in particular, macrophages. Over time, macrophages accumulate oxidized lipoproteins in themselves and form foam cells. So the fat strips on the artery wall are formed, which are then transformed into plaques.
Therefore, one of the most serious factors for the development of atherosclerosis is arterial hypertension. If there is a violation of lipid metabolism, it almost always leads to atherosclerosis.
How Diabetes Cause Atherosclerosis
With diabetes, Lipid and carbohydrate metabolism are broken. Also, with diabetes, the walls of the vessels suffer. This disease belongs to the risk factor for the occurrence of atherosclerosis.
Important: Atherosclerosis and meat.
It would seem that we understand that exogenous cholesterol does not carry the risk of vessels, meat food should be rehabilitated. But not everything is so simple. If you look at the statistics, then vegetarian diseases of the heart and blood vessels are sick much less often. According to the latest research, the reason for this can be wounded in the TMAO. Such an abbreviation is called trimethylamine oxide substance. Where does meat? The meat contains a lot of carnitine, which very much like intestinal bacteria. In the bacteria, the carnitine turns into trimethylamine (TMA), which is already oxidized to trimethylamine substitute (TMAO) in the liver. Currently, the TMAO is considered as one of the factors of the development of atherosclerosis, stroke, and other cardiovascular diseases. In this case, the accurate mechanism for the development of atherosclerosis under the influence of the TMAO remains incomprehensible.
What Are the Stage of Atherosclerosis?
Consider more Mechanisms and three stages of the development of atherosclerosis, where everything starts and how it ends.
Initially, fat strips and stains are formed on the inner walls of the arteries. Due to the inflammatory process, the arterial wall swells, becomes loose, and attracts more and more lipid fractions.
Atherosclerotic plaques are formed from connective tissue and lipids. At this stage, the plaques are still soft, so with a strong blood current, they can break and climb smaller vessels.
At the last stage, calcium accumulates in plaques, which makes them harder.
So far, there are discussions regarding atherosclerosis development mechanisms. It is assumed that the appearance of atherosclerotic plaques is also associated with some infections. Also, consider the role of mutations in which the walls of the arteries become more vulnerable to damaging factors.