Dissection of 25 adult Japanese cadavers revealed an artery that consistently arose from the subclavian artery and ascended between the scalenus anterior and medius muscles. This accessory ascending cervical artery, when developed, issued the dorsal scapular artery which penetrated the scalenus medius muscle. Typological discussion suggested that the accessory ascending cervical artery was a remnant of the longitudinal anastomoses along the embryonic intersegmental arteries.
Accessory ascending cervical artery
dorsal scapular artery