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.
Relations
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
hemiazygos veins; on the right side, with the
azygos vein 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
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. These includes the
★
bronchial arteries
★
esophageal arteries
★
posterior intercostal arteries
Additional images
External links
★
UCC