212 THE CIRCULATORY APPARATUS 



blood from the head and neck, the thoracic walls, and 

 the upper extremities. It is about three inches long, 

 and descends from the junction of the first right costal 

 cartilage with the sternum to its termination in the 

 right auricle, opposite the upper border of the third 

 right cartilage. 



The Veins of the Head and Neck. The facial vein 

 runs from the inner angle of the eye to the anterior 

 border of the masseter muscle, then backward below 

 the jaw, joining the anterior division of the temporo- 

 maxillary trunk to form the common facial, which 

 joins the internal jugular. 



The temporomaxillary vein (posterior facial) is a short 

 trunk, formed by the temporal and internal maxillary 

 veins. 



The temporal vein is formed by the union of the 

 superficial with the middle temporal vein, and crosses 

 over the zygoma and under the parotid to join the 

 internal maxillary vein. 



The external jugular vein is formed by the union of 

 the posterior auricular and the posterior division of 

 the temporomaxillary trunk. It descends obliquely 

 across the sternomastoid, lying between the platysma 

 and fascia. Above the clavicle it pierces the fascia 

 and joins the subclavian at the outer border of the 

 scalenus anticus; sometimes it joins the internal 

 jugular. 



The internal jugular vein commences at the jugular 

 foramen just below the junction of the inferior petrosal 

 with the lateral sinus, and descends with the external 

 carotid, then with the common carotid, to join at a 

 right angle with the subclavian vein behind the 

 clavicle, thus forming the innominate vein. It is 

 placed external to the carotid vessels, lying in the 

 same sheath with each in turn. 



The Veins of the Upper Extremity. THE SUPERFICIAL 

 VEINS. They commence from a plexus on the back 



