Posterior intercostal arteries III. Of the common subclan arteries, these paired vessels, one on each side, pass along the posterior wall of the xiphoid process towards both sides of the bodies of the 7th - 8th cervical vertebrae, where in 5 out of 6 cases they give rise to the transverse arteries of the neck, and in 1 case ( UI) do not give branches to the neck but form a common artery connecting to the common carotid artery. They then enter between the internal oblique capitis muscle and the internal rectus muscle and stretch along the lower surface of the longissimus muscle and the posterior end of the external oblique capitis muscle to the anterior border with the inner side of the sternocleidomastoid muscles. After which, they turn laterally, section