This section is from the book "Anatomy Of The Arteries Of The Human Body", by John Hatch Power. Also available from Amazon: Anatomy of the Arteries of the Human Body, with the Descriptive Anatomy of the Heart.
Before we proceed to speak of the operations of tying the trunk of the common carotid artery, the student is advised to study the anatomy of the large veins of the neck. The External Jugular Vein will be seen commencing behind and close to the angle of the lower jaw, and to the anterior border of the sterno-mastoid muscle: it is in fact a continuation of the temporo-maxillary vein: it then crosses the sterno-mastoid, running obliquely downwards and backwards, and covered by the platysma-myoides muscle, until it reaches about the centre of the clavicle; it then sinks behind and underneath the posterior border of the sterno-mastoid and terminates in the subclavian vein. It pierces the cervical fascia in two situations,—at its origin near the angle of the jaw, and at its termination above the clavicle. In its intermediate course it is situated immediately under cover of the platysma, and is comparatively superficial. Sometimes a large branch of communication will be seen passing from the external to the internal jugular vein below the angle of the jaw, and close to the sub-maxillary gland. Along the anterior border of the sterno-cleido-mastoid muscle, a large vein, the Anterior Jugular, will be observed passing down towards the sternum and covered by a portion of the cervical aponeurosis: it lies in front of the sterno-hyoid muscle, and close to the upper margin of the sternum it passes outwards behind the sterno-cleido-mastoid muscle, runs for a short distance along the upper and back part of the clavicle across a space filled with looso areolar tissue, situated between the lower part of the sterno-mastoid muscle anteriorly and the insertion of the scalenus anticus posteriorly, and finally terminates in the subclavian vein internal to the entrance of the external jugular vein, or in common with this vessel: a transverse branch of communication will sometimes be found connecting the two anterior jugular veins immediately above the sternum.