MeSH A07.231.908.130 | Dorlands/Elsevier t_20/12825973 | |
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Latin truncus brachiocephalicus | ||
The brachiocephalic artery (or brachiocephalic trunk or innominate artery) is an artery of the mediastinum that supplies blood to the right arm and the head and neck.
Contents
It is the first branch of the aortic arch, and soon after it emerges, the brachiocephalic artery divides into the right common carotid artery and the right subclavian artery.
There is no brachiocephalic artery for the left side of the body. The left common carotid, and the left subclavian artery, come directly off the aortic arch. However, there are two brachiocephalic veins.
Structure
It arises, on a level with the upper border of the second right costal cartilage, from the start of the aortic arch, on a plane anterior to the origin of the left carotid artery; it ascends obliquely upward, backward, and to the right to the level of the upper border of the right sternoclavicular articulation, where it divides into the right common carotid and right subclavian arteries. The artery then crosses the trachea in front of it obliquely from the left to the right, roughly at the middle of the trachea or the level of the ninth tracheal cartilage.
In infants, it often divides cephalad to the sternoclavicular articulation, within the anterior triangle of the neck.
Branches
The thyreoidea ima (arteria thyreoidea ima) ascends in front of the trachea to the lower part of the thyroid gland, which it supplies.
Variation
The innominate artery usually gives off no branches, but occasionally a small branch, the thyreoidea ima, arises from it. Other times, it gives off a thymic or bronchial branch.
It varies greatly in size, and appears to compensate for deficiency or absence of one of the other thyroid vessels. It occasionally arises from the aorta, the right common carotid, the subclavian or the internal mammary.