The main function of the subclavian artery is to provide blood supply to the upper limbs, as well as part of the head and neck through its several branches.
Each subclavian artery is divided into three parts based on its position relative to the anterior scalene muscle. The first part, known as the prescalene part, extends from the origin of the subclavian artery to the medial border of the anterior scalene muscle. This part gives off several branches, including the vertebral artery, which supplies part of the medulla, cerebellum, and brain; the internal thoracic artery, which supplies the anterior thoracic wall and breast tissue; and the thyrocervical trunk, which supplies blood to the larynx, trachea, esophagus, thyroid and parathyroid glands, as well as many other structures of the neck. The second part of the subclavian artery lies just behind the anterior scalene muscle and it gives off the costocervical trunk, which supplies the upper thorax and posterior deep cervical muscles. Finally, the third part, known as the postscalene segment, extends from the lateral border of the anterior scalene muscle to the lateral border of the first rib. This part gives off the dorsal scapular artery, which travels to the back to supply some muscles of the upper back and shoulder, such as the levator scapulae, trapezius muscles, and rhomboids.
