Aortic orifice
The aortic orifice (orifice of the ascending aorta) is the semilunar valve at the junction of the ascending aortic arch and the aortic arch. The hole is located almost in the middle of the aortic arch and is therefore called semilunar.
The cavity of the atria, from which the aortic trunk emerges, is limited in front by the anterior surface of the chest, and behind by the lower border of the manubrium of the sternum. Two upper half-branches of the aorta extend from the upper border of the manubrium, connecting to the ascending part of the aorta. The third pulmonary notch is adjacent to this area in front and above. More lateral is the recurrent laryngeal nerve (the largest parasympathetic nerve in the neck). The forearm emerges from the left between these structures, turns upward and goes to the right.
Lateral to the neck of the right shoulder blade there is a horizontal platform - the neurovascular bundle. It contains the brachiocephalic trunk and the subclavian artery, in addition, the recurrent fibers for the neck muscles and the phrenic nerve pass through here. This bundle is closely connected with the brachial plexus, which has a slightly wider distribution.