The thoracic aorta
is contained in the posterior mediastinal
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
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... Read More