832 



THE NERVOUS SYSTEM. 



muscle, perforates the deep cervical fascia, and divides beneath the Platysma into 

 two branches which are distributed to the antero-lateral parts of the neck. 



The ascending branch gives a filament which accompanies the external jugular 

 vein ; it then passes upward to the submaxillary region, and divides into branches, 

 some of which form a plexus with the cervical branches of the facial nerve beneath 



Sect. Cap. Lat. 



t. Ant. Major 

 )Rect. Ant, Minor 



'To Sympathetic 

 ) To Hypoglossal 



Scalp and Occipito Frontalis 



1 To Auricle 



Ill 



Trapezius 

 C. with Spin. Accessory 



FIG. 496. Plan of the cervical plexus. 



the Platysma; others pierce that muscle, supply it, and are distributed to the 

 integument of the upper half of the neck, at its fore part, as high as the chin. 



The descending branch (occasionally represented by two or more filaments) 

 pierces the Platysma, and is distributed to the integument of the side and front 

 of the neck, as low as the sternum. 



The Descending or supra ^avicular branches arise from the third and fourth 

 cervical nerves : emerging t. Uh the posterior border of the Sterno-mastoid, 

 they descend in the interval between that muscle and the Trapezius, and divide 

 into branches, which are arranged, according to their position, into three groups. 



The inner or suprasternal branches cross obliquely over the clavicular and 

 sternal attachments of the Sterno-mastoid, and supply the integument as far as 

 the median line. 



The middle or supraclavicular branches cross the clavicle, and supply the 

 integument over the Pectoral and Deltoid muscles, communicating with the 

 cutaneous branches of the upper intercostal nerves. 



The external or supra-acromial branches pass obliquely across the outer surface 

 of the Trapezius and the acromion, and supply the integument of the upper and 

 back part of the shoulder. 



