BRANCHES OF CERVICAL PLEXUS 



977 



the plexus a number of branches arise which form two main groups, the superficial 

 and the deep. 



Superficial Branches of the Cervical Plexus 



The superficial branches are described, according to the direction in which 

 they run, as ascending, transverse, and descending branches. The ascending 

 branches are the small occipital and the great auricular nerves. There is only one 

 transverse branch, the cervical cutaneous (transverse cervical), and the descending 

 branches are distinguished as the supraclavicular nerves and the cervical (hypo- 

 glossal) loop. 



The ascending branches.— (1) The small occipital nerve (fig. 751) arises from 

 the second and third cervical nerves, or from the loop between them, and runs 



Fig. 753. — Superficial Branches of the Cervical Plexus. 

 (After Hirschfeld and Leveille.) 



Posterior 



auricular 

 nerve 



Facial nerve 



Auricular br. of 



great auricular V' 



Cervical branch — {■ 



of facial / 



Cervical cutaneous 



Branches of cervical 

 cutaneous nerve \ 



Anterior supra- 

 clavicular 



Branches of 

 , great 

 auricular 



Great occipital 



Small occipital 



Great auricular 

 Mastoid br. or 2nd 

 small occipital 



Spinal accessory 



Twigs from the 

 mastoid branch 

 - Br. to levator 

 scapulae 



Posterior supra- 

 clavicular 



Middle supra- 

 clavicular 



Branches to 

 trapezius 



Middle supra- 

 clavicular 



upward andjdorsalward to the posterior border of the sterno-mastoid, where it 

 hooks around the lower border of the spinal accessory nerve and then ascends 

 along the posterior border of the muscle to the mastoid process. It pierces the 

 deep cervical fascia and passes across the posterior part of the insertion of the 

 sterno-mastoid into the superficial fascia of the scalp, in which it breaks up into 

 auricular, mastoid, and occipital terminal branches. 



(a) The auricular branch runs upward and slighly forward to reach the integument on the 

 upper median part of the auricle (pinna), which it supplies. (6) The mastoid branch is distrib- 

 uted to the skin covering the base of the mastoid process, (c) The occipital branches ramify 

 over the occipitalis muscle and are distributed to the skin of the scalp' they communicate with 

 one another and with the great occipital nerve. The branches of the small occipital nerve 

 62 



