I092 



A Manual of anatomy 



The anterior primary divisions of the second, third, and fourth 

 cervical nerves, having emerged between the corresponding inter- 

 transversales muscles, divide each into an ascending and a descend- 

 ing branch, which unite with adjacent branches to form loops. The 

 descending branch of the fourth nerve, as stated, joins the fifth, and 

 enters into the brachial plexus. The cervical plexus is therefore 

 a looped plexus, the number of loops being three. 



PHRENIC 



Fig. 444. — Scheme of the Cervical Plexus of Nerves. 

 The Descendens Cervicis Nerve is also shown. 



ic, 2C, 3c, \ Anterior Primary Divisions of 

 4c, 5c. ; Upper Five Cervical Nerves 

 " R.L. To Rectus Lateralis 

 G.A. Great Auricular 

 S.O. Small Occipital 

 S.C.M. To Sterno-cleido-mastoid 

 Sup.C. Superficial Cervical 

 S.M., S.M. To Scalenus Medius 



las' \'^° Levator Anguli Scapulje 

 Tk.,'Tr. To Trapezius 



S.A. SupVa-acromial 



S.C. Supraclavicular 



S.S. Suprasternal 



Sv. Branches to Sympathetic 

 R.A. To Rectus Capitis Anticus Major 

 et Minor 

 H. To Hypoglossal 

 Pn. To Pneumogastric (Ganglion of 

 Trunk) 

 C.C., C.C. Communicantes Cervicis 



DC. Descendens Cervicis 

 A.B.O.H. To Anterior Belly of Omo-hyoid 

 A. C. Ansa Cervicis 

 S.H. To Sternohyoid 

 S.T. To Sterno-thyroid 

 P.B.O.H. To Posterior Belly of Omo-hyoid 



Branches. — ^These are divided into two groups— superficial and 

 deep. 



Superficial Group. — ^The nerves of this group are ascending, 

 transverse, and descending. 



The ascending and transverse nerves arise from the second and 

 third cervical nerves. 



The ascending nerves are the small occipital and great auricular 

 (sec p. 1059). The transverse nerve is the superficial (transverse) 

 cervical. 



