SUPERFICIAL CERVICAL REGION. 39 



descends the neck, following a line from the angle of the 

 jaw to the middle of the clavicle, crossing the sterno- 

 mastoid muscle, and penetrates the fascia, just at the side 

 of the outer border of the clavicular portion of that muscle, 

 terminating in the subclavian vein. In its course it is joined 

 by the veins which accompany the supra-scapular and pos- 

 terior scapular arteries in the posterior part of the neck. 

 The anterior jugular vein, formed by a series of small 

 branches, collects the blood from the front of the neck, and 

 descending along the anterior border of the sterno-mastoid 

 muscle, sometimes enters the external jugular, and some- 

 times passes beneath the sterno-mastoid, to join the inter- 

 nal jugular or subclavian vein. 



The cervical fascia is to be removed in dissecting the nervous 

 branches which ramify in this region ; for the most part these emerge 

 behind the sterno-mastoid, and are to be followed to their origin be- 

 neath that muscle so far as may be, without dividing it. The infra- 

 maxillary branches of the cervico-facial division of the facial nerve 

 (p. 23) will be found beneath the platysma, between the inferior 

 maxilla and the hyoid bone. 



The anterior branches of the four upper cervical nerves 

 communicate with each other by loops, and these loops, 

 together with their branches, constitute the cervical plexus ; 

 emerging from under the posterior border of the sterno- 

 mastoid muscle, and covered in by the platysma, it is dis- 

 tributed to the muscles and integument. Its branches are 

 divided into ascending, descending, and deep. 



The ascending branches are three in number: 



Superficialis colli, 

 Auricularis magnus, 

 Occipitalis minor. 



The snperficinlis colli nerve, coming from the second and third 

 cervical nerves, emerges behind the posterior border of the sterno- 

 mastoid, at about its middle, crosses it in a direction obliquely 

 upward, and divides into ascending and descending branches, which 

 are distributed to the front of the neck. 



The auricnlaris magnus nerve comes also from the second and third 

 cervical nerves, and emerges at the posterior border of the sterno- 

 mastoid, on the superficial surface of which it ascends, in close relation 

 with the external jugular vein, to the parotid gland, where it divides 

 into two branches, the anterior being distributed to the external ear, 

 parotid gland, and cheek ; the posterior, crossing the mastoid process, 

 supplying the back part of the external ear and the integument in its 

 neighborhood. 



The occipilal'ts minor nerve arises from the second cervical nerve, and 



