The aorta is divided into 3 sections: the ascending aorta, the aortic arch and the descending aorta.

The human circulatory system is closed and consists of two circles of blood circulation and a four-chambered heart.

Systemic circulation (bodily) – starts from the left ventricle , from which arterial blood enters the aorta and arteries extending from it. Arteries branch, become thinner and gradually pass into arterioles, capillaries. Through the walls of the capillaries, gas exchange and metabolism occurs between the blood and tissues. As a result, the blood from the arterial becomes venous and enters the venules, then into the veins. The veins of the upper half of the body flow into the superior vena cava, the veins of the lower half of the body flow into the inferior vena cava. The superior and inferior vena cava empty into the right atrium.

The role of the BCC. The arteries of the systemic circulation with arterial blood deliver oxygen and nutrients to all cells of the body, the veins carry away carbon dioxide and metabolic products with venous blood. The circulation of blood in the BCC occurs in 23 seconds.

The pulmonary circulation (pulmonary) begins from the right ventricle , from which venous blood enters the pulmonary trunk (common pulmonary artery), which divides into the right and left pulmonary arteries, which carry venous blood to the corresponding lung. In the lungs, the arteries branch to the capillaries that surround the alveoli. Here gas exchange takes place and the blood from the venous becomes arterial. Two (upper and lower) pulmonary veins emerge from each lung, carrying arterial blood to the left atrium. The circuit in the ICC takes 4 seconds.

Role: regeneration of blood gases.

Coronary circle of the heart (blood supply to the heart). Fig.1 Coronal circle of the heart

The heart receives arterial blood from two coronary (coronary) arteries (right and left)

Both of them start from the aorta, just above the semilunar valves, and pass in the coronal sulcus of the heart, which separates the atria from the ventricles.

In all layers of the heart wall, arterial branches divide into smaller ones and form a capillary network, providing gas exchange and nutrition of the heart wall. The blood becomes venous, passes into the venules, and then into the heart’s own veins, which flow into the coronary sinus, which opens into the right atrium

The aorta (Greek aorta – rising, that is, pulsating) is the main artery of the systemic circulation, which, through its branches, supplies arterial blood to all organs and tissues of the body.

It emerges from the left ventricle and continues to the level of the IV lumbar vertebra.

Departments of the aorta

The aorta is divided into 3 sections: the ascending aorta, the aortic arch and the descending aorta.

In the descending part , the thoracic and abdominal parts of the aorta are distinguished.

The ascending aorta, or ascending aorta, is the initial section of the aorta, about 6 cm long, about 3 cm in diameter, located in the anterior mediastinum posterior to the pulmonary trunk. The initial expanded part of the ascending aorta is called the aortic bulb , from which its first two branches depart – the right and left coronary arteries of the heart, supplying the heart itself.

Behind the handle of the sternum, the ascending aorta passes into the aortic arch, which goes back and to the left and, spreading through the left main bronchus, at the level of the IV thoracic vertebra, passes into the descending (thoracic) part of the aorta.

Branches of the aortic arch

From the convex surface of the aortic arch depart

3 major branches:

1. brachiocephalic trunk, 2. left common carotid artery, 3. left subclavian artery. These vessels carry blood to the arteries of the head, neck, upper extremities and partly to the anterior chest wall.

Arteries of the neck and head

1. The brachiocephalic trunk is an unpaired vessel, goes upwards from the aortic arch, has a length of about 4 cm, at the level of the right sternoclavicular joint it is divided into the right common carotid and right subclavian arteries.

3. The left common carotid artery is a branch of the aortic arch . The right common carotid artery arises from the brachiocephalic trunk.

The common carotid artery (left and right) rises up the neck near the esophagus and trachea and divides into the external and internal carotid arteries at the level of the upper edge of the thyroid cartilage

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