Aortic arch | Anatomy of aortic arch | Medicoze

The arch of the aorta passes upwards from the sternal angle behind the manubrium to arch backwards and to the left over the left lung root, and then descends to the left side of the 4th thoracic vertebra. From the convexity of the arch arise the three arteries supplying the head, neck and upper limbs.

Relations

To the left of the arch of the aorta lie the mediastinal pleura and lung, the left phrenic nerve and the left vagus nerve. To its right lie the superior vena cava, the trachea and left recurrent laryngeal nerve, the oesophagus and thoracic duct and, finally, the 4th thoracic vertebra. Inferiorly, the aortic arch crosses the bifurcation of the pulmonary trunk, the ligamentum arteriosum and the left main bronchus. Superiorly are its three branches. The arch is connected inferiorly to the left pulmonary artery by the ligamentum arteriosum, a fibrous remnant of the ductus arteriosus. The left recurrent laryngeal nerve passes posteriorly around the ligamentum and the arch. The cardiac plexus is closely related to the ligamentum. Remnants of the thymus gland may be found in front of the arch.

Branches

The first branch, the brachiocephalic artery, arises behind the manubrium and ascends as far as the right sternoclavicular joint, there to divide into two terminal branches, the right subclavian and right common carotid arteries. Anteriorly, the left brachiocephalic vein and thymus separate it from the manubrium; posteriorly lies the trachea. To its right lie the right brachiocephalic vein and superior vena cava, and to its left is the left common carotid artery. The leftcommon carotid artery arises from the arch just behind the brachiocephalic artery and passes upwards alongside the left side of the trachea into the neck. The left subclavian artery arises behind the left common carotid artery and arches to the left over the dome of the left pleura behind the left sternoclavicular joint and over the first rib.