Arch of the aorta
Segment · T4/T5 Superior mediastinum 3 branches
Continuation of the ascending aorta in the superior mediastinum; begins and ends in the plane of the sternal angle (T4/T5), arching backward and to the left over the left main bronchus. Three branches leave its convexity, right to left: brachiocephalic trunk, left common carotid, left subclavian.
Detail
- Level
- Begins and ends at the sternal angle plane (T4/T5); apex at mid-manubrium
- Branches
- Brachiocephalic trunk, left common carotid, left subclavian
- Relations
- Ligamentum arteriosum tethers its concavity to the left pulmonary artery; the left recurrent laryngeal nerve hooks beneath the arch lateral to the ligamentum; left vagus and left phrenic cross its left side
When it goes wrong
Aortic arch aneurysm
Compresses the left recurrent laryngeal nerve as it hooks under the arch: hoarse voice with left vocal cord palsy (Ortner's syndrome); may also cause dysphagia or stridor
Sudden deceleration (high-speed collision, fall from height)
Traumatic aortic transection at the isthmus, just distal to the left subclavian, where the mobile arch is fixed by the ligamentum arteriosum; widened mediastinum on chest X-ray
Practise this structure
3 questions in the bank tagged Thorax.
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