THE HEAD AND NECK. 



75 



transverse branch ; the great auricular, small occipital, and lesser or second 

 occipital are ascending. These branches had to undergo this very distribution 

 to carry out the scheme of distribution of the cervical nerves a scheme we 

 everywhere invoke when we would account for sensory nerve distribution. 



The communicating branches are : 



i. Extrinsic, as your dissection should show, with the auriculo-temporal, 

 the facial, the intercostals, the circumflex, and the great occipital. 



FIG. 41. SCHEME OF THE CERVICAL PLEXUS. 

 Note the loops by which one nerve communicates with the next. 



2. Intrinsic : with the hypoglossal, sympathetic, pneumogastric, spinal acces- 

 sory, and brachial plexus, for reasons set forth in a foregoing paragraph. 



External and Internal Series of Muscular Branches of the Cervical 

 Plexus. The scalenus medius, trapezius, levator anguli scapulae, and sterno- 

 cleido-mastoid are, according to the time-honored classification, given as the 

 external series, while all the remaining muscles would naturally fall to the internal 



