Subclavian artery: origins on each side, course between the scalenes, branches

Where does the subclavian artery run?

Blood bound for the arm leaves the root of the neck by passing under the collarbone. Its route is the subclavian artery, named for running just below the clavicle.

In the view above both subclavian arteries are yellow, running sideways under the clavicles toward the arms. The origins differ: the right is the continuation of the brachiocephalic trunk after it gives off the right common carotid, while the left arises directly from the aortic arch, so the left is a little longer.

Between the scalenes

It arches over the pleura covering the apex of the lung and passes through the gap between the anterior and middle scalenes together with the brachial plexus. The subclavian vein passes in front of the anterior scalene, so artery and vein are separated by the muscle, which divides the artery into medial, posterior and lateral parts. At the outer border of the first rib it becomes the axillary artery; the vessel itself is continuous.

Main branches

The vertebral artery is the brain's second supply route alongside the internal carotid artery, entering the skull through the posterior atlanto-occipital membrane. The number and order of branches vary, and textbooks count them differently.

Name and terms

Sub- means below and clavian refers to the clavicle. Related terms: vertebral artery, internal thoracic artery, interscalene triangle. The Latin is arteria subclavia.

See it in the app

Hidden between the clavicle and first rib, and with different origins on each side, the subclavian arteries are easy to misread in a single drawing. In the 3D anatomy app teamLabBody you can keep only the vessels and bones, select both arteries and compare how they leave the aortic arch, then add the muscles to see them pass between the scalenes. Cross sections are available with the PREMIUM plan.

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