Page:Structure and functions of the body; a hand-book of anatomy and physiology for nurses and others desiring a practical knowledge of the subject (IA structurefunctio00fiskrich).pdf/114

 divides into the right common carotid and right subclavian. The common carotids pass up the neck behind the sterno-cleido-mastoid muscles in a line from the sterno-*clavicular joint to a point midway between the mastoid process and the angle of the lower jaw and divide opposite the upper border of the thyroid cartilage into the internal and external carotids, of which the former with its branches supplies the anterior part of the brain, the eye and forehead, and the latter the neck and face. —The aortæ and their branches. (Leidy.) The subclavian is the artery of the upper extremity but its vertebral branch goes to the brain, where with its fellow it forms the basilar artery, whose branches together with the branches of the internal carotid form the circle of Willis at the base of the brain. Other branches of the subclavian are the thyroid axis, with branches to the neck and shoulders; the internal mammary, with branches to the chest walls, mediastinum, and diaphragm, such as the musculo-*phrenic and superior epigastric; and the superior intercostal. At the lower border of the first rib, over which it passes, the name axillary is substituted for subclavian, while at the lower border of the axilla, where it starts down the arm, it is called the brachial artery. At the elbow the brachial divides into the radial and ulnar arteries. The axillary