At the very beginning of the XVII century there were no scientifically proven facts about the human circulatory system. Until a certain point, it was believed that the central point of blood flow is not the heart, but the liver. Everything changed in 1616, when the doctor William Harvey said that the heart begins to circulate, and the blood circulates through the vessels constantly.
How is the circulatory system
Blood circulation in the human body passes through two circles: large and small. First, blood, saturated with oxygen and nutrients, is delivered to the periphery: organs and tissues. The beginning of the circle lies in the left ventricle of the heart, where the left atrium initially pushes blood. The largest artery in our body, the aorta, departs from the left ventricle. Branching up to the smallest vessels, the system carries blood throughout the body. In the periphery, it enters the venules, and then into the veins. The latter, connecting, form the superior and inferior vena cava, which flow into the right atrium. This is where the big circle of blood circulation ends.
Pulmonary circulation
In this circle, everything is a little wrong. If arterial blood flows in large arteries and venous blood flows through veins, as is commonly believed, then here arterial blood flows through veins, and venous flow through arteries. How so? Let's dig into the anatomy.
The small circle begins with the right ventricle, in which, again, the blood entered with the help of the atrium. Further, the path lies through the pulmonary trunk, and then into the vascular system of the lungs. The lungs are fed by two main vessels: the right and left pulmonary artery. Blood is saturated with oxygen and through four pulmonary veins goes back to the heart in the left atrium.
Arterial blood is not the blood that flows through the arteries, but that which is saturated with oxygen. It is the same with venous - it carries metabolic products, such as carbon dioxide. So it turns out that in a small circle in the veins - arterial blood, and in the arteries - venous.
Aortic structure
The artery is divided into three parts: ascending, descending and its arc. It originates from the aortic opening, which is located in the left ventricle, then goes up, bending into a kind of arc. Three large vessels depart from the arc: the left common carotid artery, the left subclavian and the brachiocephalic trunk. After this, the vessel smoothly passes into the descending aorta. Here there is a conditional division into the thoracic and abdominal parts.
- Dimensions of the ascending aorta: length - about 5 cm, width - 3.2 ± 0.5 cm.
- Arc: width 1.5 ± 1.2 cm.
- Downstream: Width 2.5 ± 0.4 cm.
Development of the cardiovascular system
From the third week of pregnancy, the fetus begins to form the cardiovascular system to begin the implementation of independent circulation. Development ends around the eighth week, that is, in general, the bookmark occurs in about 35 days. This month with a little, some women still do not know about their pregnancy and do not change their usual way of life, lifting weights, taking alcohol and medications that are forbidden to pregnant women. And it is from the fifth to the eighth week that all this affects the heart and blood vessels. Therefore, it is so important to lead a healthy lifestyle in the early stages. At the eighth week of pregnancy, the fetus begins to develop an interventricular septum and a septum separating the pulmonary trunk and the aorta. So the heart turns into a four-chamber.
Circulatory function
Contraction of the heart leads to the launch of blood flow through the body. Blood flows from the highest to the least pressure. In the arteries, this occurs pulsatingly, under pressure, which we usually measure with a tonometer. Blood pressure is the first indicator that reflects the health of the cardiovascular system. It is divided into systolic and diastolic. Systolic is the pressure in the vessels during ventricular contraction, and diastolic is during relaxation. The difference between the indicators is called average or pulse. According to pressure and heart rate, you can initially assess the state of heart health.
Aortic aneurysm
Any organ of our body and arteries can become ill with no exception. If we take precisely the pathology of the aorta, then aneurysm is the most common of all.
What is it? This is an expansion of the vessel wall, a kind of protrusion, which is accompanied by a decrease in its wall. According to statistics, most often men suffer from it. As you know, the male sex, in principle, has a predisposition to cardiovascular disease. For example, it is rather difficult to meet a woman suffering from coronary heart disease and having myocardial infarction, unlike men.
Complications
So, what does this condition threaten? The most dangerous complication is a gap. As already noted, an aneurysm is a “bag” of a distended vascular wall. Accordingly, it is quite fragile. For example, pressure will increase, there will be a violation of the integrity of the wall, and within a few seconds, internal bleeding will begin with the participation of all circulating blood (which is 3-5 liters). Naturally, even with the provision of instant medical care, the fate of the patient is already destined.
Symptoms
The first symptom that the patient will notice is pain behind the sternum. Most often, it occurs in the morning after sleep. Aneurysm increases, the wall stretches more and more. The pain appears due to the presence of receptors in the wall.
There are distinctive symptoms of aneurysm namely the ascending aorta. Since the esophagus is nearby, and the aneurysm can put pressure on it, a symptom such as a violation of swallowing appears. If the trachea or the main bronchus is squeezed, then a reflex cough occurs, which is not stopped by any drugs.
Diagnostics
For any heart discomfort, consultation with an appropriate specialist is required. If aortic pathology is suspected, the cardiologist directs the patient to echocardiography. This is the so-called ultrasound of the heart, on which you can look not only at the operation of all valves and blood vessels, but also at their size, which will be most interesting for the doctor in this situation. During the study, the width and length will be fixed. We recall that the diameter of the ascending aorta is normal 3.2 ± 0.5 centimeters. Next, the doctor who conducted the study will compare the indicators, write the conclusion of the study, and send them to the attending physician. If, nevertheless, the ascending aorta is dilated, and this diagnosis is made, then the cardiologist sends the patient to a cardiac surgeon for a consultation on a further plan of action. The treatment is usually surgical.
Sealing of the walls of the ascending aorta
Causes:
- atherosclerosis;
- senile age;
- arterial hypertension;
- inflammation;
- syphilis;
- tuberculosis.
Atherosclerosis is the most common cause of compaction of the ascending aorta. The wall of the artery condenses and thickens due to the deposition of cholesterol plaques in it. This pathology can lead to aneurysm, stratification of the artery walls, narrowing of the lumen of the vessel, which increases the load on the heart.
Comparison table of the ascending aorta in normal and pathological conditions.
| Norm | Pathology |
| Healthy wall | Thickened wall |
| Soft, elastic | Solid, dense |
| The same thickness in all areas | Has areas of thickening |
| Elastic, can stretch | Not stretchable |
Important symptoms and diseases that accompany this condition may include:
- pain behind the sternum;
- coronary artery disease;
- lesions of the aortic valve;
- left ventricular hypertrophy.
Is there a cure?
Appointments by a cardiologist are completely dependent on the causes of the disease. If the cause is atherosclerosis, then a strict diet, anti-sclerotic drugs and antiplatelet agents are prescribed. With hypertension, the output is its treatment. Unfortunately, there is no cure for old age.