||This article may be too technical for most readers to understand. (July 2009)|
|Artery: Thoracic aorta|
The thoracic aorta, viewed from the left side.
Histopathological image of dissecting aneurysm of thoracic aorta in a patient without evidence of Marfan's trait. The damaged aorta was surgically removed and replaced by artificial vessel. Victoria blue & HE stain.
|Latin||pars thoracica aortae, aorta thoracalis|
|Branches||bronchial arteries, esophageal arteries, posterior intercostal arteries, abdominal aorta|
The thoracic aorta is contained in the posterior mediastinal cavity.
It begins at the lower border of the fourth thoracic vertebra where it is continuous with the aortic arch, and ends in front of the lower border of the twelfth thoracic vertebra, at the aortic hiatus in the diaphragm where it becomes the abdominal aorta.
At its commencement, it is situated on the left of the vertebral column; it approaches the median line as it descends; and, at its termination, lies directly in front of the column.
The vessel describes a curve which is concave forward; as the branches given off from it are small, its diminution in size is insignificant.
It has a radius of approximately 1.16 cm.
It is in relation, anteriorly, from above downward, with the root of the left lung, the pericardium, the esophagus, and the diaphragm; posteriorly, with the vertebral column and the azygos vein; on the right side, with the hemiazygos veins and thoracic duct; on the left side, with the left pleura and lung.
The esophagus, with its accompanying plexus of nerves, lies on the right side of the aorta above; but at the lower part of the thorax it is placed in front of the aorta, and, close to the diaphragm, is situated on its left side.
Branches before thoracic aorta
The initial part of the aorta, the ascending aorta, rises out of the left ventricle, from which it is separated by the aortic valve. The two coronary arteries of the heart arise from the aortic root, just above the cusps of the aortic valve.
The aorta then arches back over the right pulmonary artery. Three vessels come out of the aortic arch, the brachiocephalic artery, the left common carotid artery, and the left subclavian artery. These vessels supply blood to the head, neck, thorax and upper limbs.
Branches of thoracic aorta
The aorta gives off several paired branches as it descends in the thorax. In descending order, these include the
- Bronchial arteries
- Mediastinal arteries
- Esophageal arteries
- Pericardial arteries
- Superior phrenic artery
Note: The posterior intercostal arteries are branches that originate throughout the length of the posterior aspect of the thoracic aorta.