aortic arch
Last reviewed 01/2018
The aortic arch is that region of the aorta within the superior mediastinum between the ascending aorta and the thoracic aorta.
It develops from the fourth pharyngeal arch. In the fetus there is communication between the aortic arch and the pulmonary artery via the ductus arteriosus. This later becomes the ductus arteriosus.
The arch has stretch receptors in its outer wall which are used in the regulation of blood pressure.
The aortic arch may be prone to developmental anomalies or acquired aneurysms.
The distal section of the arch may be seen on anteroposterior radiographs as a distinct shadow superior to the left side of the heart - the aortic knuckle.