Aorta

The aorta , aorta, is the largest arterial vessel in the human body. It comes out of the left ventricle; Its beginning is the opening of the aorta, ostium aortae. From the aorta all arteries that form a large circle of blood flow away.

In the aorta, the ascending aorta (ascending aorta), pars ascendens aortae (aorta ascendens), the arch of the aorta, arcus aortae, and the descending aorta (descending aorta), pars descendens aortae (aorta descendens) are distinguished in the aorta. The latter in turn is divided into the thoracic part of the aorta (thoracic aorta), pars thoracica aortae (aorta thoracica), and the abdominal part of the aorta (abdominal aorta), pars abdominalis aortae (aorta abdominalis).

The ascending part of the aorta , pars ascendens aortae, originates in the left ventricle from the aortic aperture. Behind the left half of the sternum, at the level of the third intercostal space, it goes up, slightly to the right and forward and reaches the level of the cartilage of the 2nd rib on the right, where it continues into the arch of the aorta.

The beginning of the ascending part of the aorta is enlarged and is called the bulb of the aorta, bulbus aortae. The wall of the bulb forms three protrusions - aortic sinuses, sinus aortae, corresponding to the position of the three half-moon aortic flaps.

Just like the flaps, these sinuses designate: right, left and posterior.

From the right sine origin a. Coronaria dextra, and from the left - a. Coronaria sinistra.

The arch of the aorta , arcus aortae, is convex upward and directed from front to back, passing into the descending part of the aorta. In the site of the transition there is a noticeable slight narrowing-the isthmus of the aorta, isthmus aortae. The aortic arch has a direction from the cartilage of the 2nd rib on the right to the left surface of the III-IV thoracic vertebrae.

Three large vessels leave the arch of the aorta: the brachiocephalic trunk, truncus brachiocephalicus, the left common carotid artery, a. Carotis communis sinistra, and left subclavian artery, a. Subclavia sinistra.

The brachiocephalic trunk, truncus brachiocephalicus, departs from the initial part of the aortic arch. It is a large vessel up to 4 cm long that goes up and to the right and divides into two branches at the level of the right sternoclavicular joint: the right common carotid artery, a. Carotis communis dextra, and the right subclavian artery, a. Subclavia dextra. Sometimes the lower thyroid artery departs from the brachiocephalic trunk, a. Thyroidea ima.

Rarely there are variants of development: 1) the brachiocephalic trunk is absent, the right common carotid and right subclavian arteries in this case directly extend from the arch of the aorta; 2) the brachiocephalic trunk departs not to the right, but to the left; 3) there are two brachiocephalic trunks, right and left.

The descending part of the aorta , pars descendens aortae, is an extension of the aortic arch and lies from the body of the III - IV thoracic vertebra to the level IV of the lumbar vertebra, where it gives the right and left common iliac arteries, aa. Iliacae communes dextra et sinistra, and itself continues into the pelvic cavity in the form of a thin trunk - the median sacral artery, a. Sacralis mediana, which runs along the front surface of the sacrum.

At level XII of the thoracic vertebra, the descending part of the aorta passes through the aortic aperture of the diaphragm and descends into the abdominal cavity. Before the diaphragm, the descending part of the aorta is called the thoracic part of the aorta, pars thoracica aortae, and below the diaphragm - the abdominal part of the aorta, pars abdominalis aortae.