The aorta (main artery) is one of the key elements of the circulatory system. The proper functioning of the aorta is essential for the supply of oxygen and nutrients to all organs. Find out how the aorta is structured, how the aorta works, what are the most common aortic diseases and how to diagnose and treat aortic diseases.
Aortais the mainarteryof the human body. Blood enters the aorta directly from the left ventricle. The aorta then runs through the thorax and abdominal cavity, making numerous branches. The arteries that leave the aorta supply blood to all organs of our body.
Aorta - anatomy
Aorta is the largest artery in the human body. The aorta begins in the chest and is directly connected to the left ventricle. The course of the aorta resembles a curved cane with 3 parts:
- ascending part,
- aortic arch
- and the descending part.
The ascending aorta is connected to the heart and runs inside the pericardial sac around it. In the ascending aorta there are the outlets of the coronary arteries that supply the heart muscle with blood.
The second part of the aorta - the aortic arch - is located behind the sternum. In this section, the aorta gives off 3 large arteries that supply blood to the upper parts of the body - the head, neck, and upper limbs. The names of these vessels are: the brachiocephalic trunk, the left common carotid artery and the left subclavian artery.
The last segment of the aorta - the descending part - runs vertically down the spine. It is the longest of all sections of the aorta - it begins in the chest, then goes through the diaphragm and ends in the abdominal cavity.
At the level of the diaphragm, there is an arbitrary division of the descending aorta into the thoracic and abdominal aorta. The descending aorta forms numerous branches that supply blood to the organs of the chest and abdomen. The aorta ends at the division into a small median sacral artery and 2 large iliac arteries that carry blood to the lower extremities.
Among the branches of the descending aorta in the thoracic area, it is worth mentioning the pericardial, esophageal, bronchial and intercostal branches, which vascularize both internal and external organs.and the chest wall.
In the abdominal part, the aorta captures 3 large visceral arteries: the celiac trunk and the superior and inferior mesenteric arteries. These vessels carry blood to the stomach, intestines, pancreas, liver, and spleen. Additionally, the aorta pumps blood to the paired renal, adrenal, and ovarian (female) or nuclear (male) arteries. So we see that the aorta supplies blood to basically all the internal organs of our body.
Aorta - functions
Aorta belongs to the so-called the large bloodstream, which is the system of vessels that carry blood from the heart to all organs of the body. As blood enters the aorta directly from the heart, it is under relatively high pressure - 90-130 mmHg during contraction, and 50-90 mmHg during its diastole. The blood flow rate in the aorta reaches 20-50 cm / s. The structure of the aorta must therefore ensure its adequate flexibility and strength.
When viewing the aortic wall under a microscope, 3 distinct layers can be seen. The innermost of these is the vascular endothelium, which forms the smooth lining inside the aorta. The role of the endothelium is to ensure a continuous, free flow of blood.
The middle layer of the aorta is composed of numerous muscular and elastic fibers that allow the aorta to expand and contract rhythmically in line with the pulse wave.
The outermost part of the aortic wall - the adventitia - consists mainly of collagen fibers, ensuring adequate strength.
A unique feature of the aorta is the presence of the so-called vasa vasorum (Latin for "utensils"). These are tiny blood vessels that run through the wall of other large vessels.
The aortic wall is so thick that it is not enough to nourish it with blood flowing inside it - it needs additional vessels that also provide blood supply from the outside.
In the context of the functioning of the aorta, it is worth paying attention to the fine structure separating the aorta from the left ventricle of the heart. It is the aortic valve. When the left ventricle contracts, the aortic valve opens, allowing blood to flow from the heart to the aorta. And when the heart muscle relaxes, the aortic valve closes, preventing blood from flowing back to the heart. Diseases of the aortic valve are one of the most common acquired cardiovascular defects.
Aorta is a large vessel worth looking at in the context of the entire circulatory system. Diseases of the aorta directly affect other organs of this system, especially the heart muscle. For example, aortic stenosis is a medical condition that makes it difficult for blood to pump from the heart into the aorta.
Its effect is reducedsupply of organs with blood. As a pump that pumps blood, the heart must generate higher pressures in order to overcome resistance. This is done at the expense of myocardial hypertrophy of the walls of the heart. Aortic dysfunction causes changes in the entire circulatory system.
Aorta - diseases
Aortic diseases can be divided into congenital and acquired. The most common congenital abnormalities of the aorta are the bicuspid aortic valve and aortic stenosis, professionally known as coarctation. Acquired aortic diseases, such as aortic aneurysms and aortic valve defects predominate, are much more common.
Aortic aneurysm
Aneurysm is a local expansion of a vessel by more than 50% in relation to its normal diameter. Aortic aneurysms are relatively common - according to various studies in European populations, this problem affects 5 to 10% of men.
Aneurysms are much less common in women. Aneurysms can occur in all parts of the aorta, although they are most often formed in the abdominal part of the aorta. What causes aneurysms? They are usually the result of atherosclerotic changes in the vessels, as well as vascular damage caused by arterial hypertension, smoking or elevated cholesterol levels.
It is also worth knowing that there are genetic diseases that increase the risk of aneurysms. Their example is Marfan's syndrome, in which the disruption of collagen formation increases the risk of aneurysms in the artery walls.
The greatest danger associated with the presence of an aneurysm is the risk of it rupturing. As the blood in the aorta flows under high pressure, rupture of the aortic aneurysm carries the risk of a life-threatening hemorrhage. Unfortunately, many aortic aneurysms remain completely asymptomatic.
They are usually detected accidentally during imaging examinations of the chest or abdominal cavity. Symptoms do not usually develop until the aneurysm grows large. In thoracic aortic aneurysms, the most common symptom is coughing and pain between the shoulder blades. Abdominal aortic aneurysms can cause pain in the abdomen or in the lumbar region.
The most effective method of treating aortic aneurysms is their surgical removal, combined with implantation of a prosthesis in the place of the removed fragment of the vessel. It is also advisable to stop smoking, to eat a proper diet and to control concomitant cardiovascular diseases (hypertension, hypercholesterolaemia).
Aortic valve defects
Aortic valve defects can be divided into congenital and acquired. The most common congenital malformation of the aortic valve isthe so-called a bicuspid aortic valve. This disease consists of an abnormal aortic valve structure, which has only 2 instead of 3 leaflets. Such a valve structure often does not cause any clinical symptoms, but at the same time may predispose to other valve disorders.
The most common acquired diseases of the aortic valve are its stenosis (i.e. stenosis) and regurgitation. Aortic stenosis makes it difficult to pump blood from the left ventricle into the aorta. This results in an increased workload on the heart and reduced blood flow to all organs. Aortic regurgitation, on the other hand, causes blood to flow back from the aorta to the heart as it relaxes. Symptomatic aortic valve defects may be an indication for its surgical replacement.
Aorta - birth defects
An example of a typical congenital aortic defect is coarctation, or narrowing of the aortic isthmus. The course of the disease depends on how narrowed the aorta is (in extreme cases, it may be completely overgrown).
Treatment of such a defect in a newborn consists in maintaining the patency of vessels that are normally active only during fetal life. In this way, blood supply to all organs can be temporarily ensured. The target treatment is a surgical procedure that restores the proper patency of the aorta.
Aortic injuries
One of the common causes of a traumatic aortic injury is a communication accident with the chest hitting the steering wheel. The effects of such an event are similar to those of an aortic aneurysm rupture - the patient requires immediate treatment, as hemorrhages from the damaged aorta cause massive blood loss and pose a direct threat to life.
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