The aorta is the body’s largest artery, originating from the left ventricle of the heart. It plays a central role in systemic blood circulation by distributing oxygen-rich blood throughout the body. The aortic arch, a curved segment of the aorta, directs blood supply to the upper body. This section ensures the head, neck, and upper limbs receive oxygen and nutrients.
The Aortic Arch’s Main Branches
The aortic arch typically gives rise to three distinct arterial branches. These branches emerge in a specific order, each with its own initial course.
The first and largest branch is the brachiocephalic artery, also known as the brachiocephalic trunk or innominate artery. This artery arises from the aortic arch to the right and slightly anterior to the other two branches. After a short upward course, it divides into two arteries: the right common carotid artery and the right subclavian artery.
The second branch originating directly from the aortic arch is the left common carotid artery. It ascends along the left side of the trachea and through the superior mediastinum. While its counterpart on the right side branches off the brachiocephalic artery, the left common carotid artery has a direct origin from the aortic arch.
The third main branch of the aortic arch is the left subclavian artery. This artery arises distal to the left common carotid artery. Unlike the right subclavian artery, which originates from the brachiocephalic artery, the left subclavian artery emerges directly from the aortic arch.
Journey and Supply of Each Artery
Each of the three arteries branching from the aortic arch delivers oxygenated blood to the upper body. Their distribution supports the function of organs and limbs.
The brachiocephalic artery, after its origin from the aortic arch, bifurcates into the right common carotid artery and the right subclavian artery. The right common carotid artery then travels upwards, supplying the right side of the head and neck. Meanwhile, the right subclavian artery extends towards the right upper limb, supplying the arm, forearm, and hand, and also contributing to blood supply to parts of the head and thorax.
The left common carotid artery supplies the left side of the head and neck. Both common carotid arteries, on the left and right, eventually divide into internal and external carotid arteries to distribute blood to specific areas of the brain, face, and neck.
The left subclavian artery extends into the left upper limb. This artery supplies the left arm, including the shoulder, as well as contributing to the blood supply of the left side of the chest and parts of the neck and brain. The coordinated function of these arteries ensures a continuous supply of blood to the upper extremities and the head.