THE CER VICAL PLEXUS 



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The Descending or Supraclavicular Branches (nn. supraclaviculares) (Fig. 754) 

 a rixe from the third and fourth cervical nerves; emerging beneath the posterior 

 border of the Sternomastoid, they descend in the posterior triangle of the neck 

 beneath the Platysma and deep cervical fascia. Near the clavicle they perforate 

 the fascia and Platysma to become cutaneous, and are arranged, according to 

 their position, into three groups. 



.R.C.A. MIN. 



* f,R.A. MAJ. 



COMMUNICATING TO 

 HYPOGLOSSAL 



SYMPATHETIC 



UONGUS COLU & 

 RECTUS ANT. MAJOR 



TO GEMOHYOID 

 Ma 

 TO THYROHYOID 



SUBMANDIBULAR 

 BR. OF FACIAL 



LEVATOR ANGULI SCAP 

 A SCALENUS MEDIUS \ >. 



FROM SYMPATHETIC 



FIG. 755. Plan of the cervical plexus. (Gerrish.) 



The Inner or Sternal Branches (////. supraclaviculares anteriores) cross obliquely 

 over the external jugular vein and the clavicular and sternal attachments of the 

 Sternomastoid muscle, and supply the integument as far as the median line. 

 They furnish one or two filaments to the sternoclavicular joint. 



The Middle or Clavicular Branches (nn. supraclaviculares medii) 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 Acromial Branches (nn. supraclaviculares poster tores') pass 



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