CEEVICAL NEKVES. 



689 



capitis (O.T. complexus), rectus capitis posterior major and minor, and obliqui 

 capitis, superior and inferior. 



(&) A communicating branch descends to join the second cervical nerve. 



The communicating branch may arise in common with the nerve to^the obliquus inferior, 

 and reach the second cervical nerve by piercing or passing superficial or deep to that muscle ; 

 or it may accompany the nerve to the semispinalis capitis and communicate with the greater 

 occipital nerve, under or over that muscle. 



Second Cervical Nerve. The posterior ramus of this nerve is larger than 

 the corresponding anterior ramus. It passes backwards between the atlas and 

 epistropheus, and in the interval between the obliquus inferior and the semispinalis 

 cervicis muscles, under cover of the semispinalis capitis muscle. In this situa- 



Insertion of sternp-. 

 mastoid 

 Splenius capiti 

 Longissimus capitis 



Semispinalis capitis 



OCCIPITAL NERV 



Splenius capit 



Longissimus capitis< 



-Attachment of trapezius 

 Insertion of semispinalis capitis 



REATER OCCIPITAL NERVE 



Obliquus superior 

 Rectus capitis posterior major 

 Rectus capitis posterior minor 

 Vertebral artery 

 * POSTERIOR RAMUS OF 

 SUBOCCIPITAL NERVE 

 Posterior arch of atlas 



POSTERIOR RAMUS OF SECOND CERVICAL 



NERVE 



POSTERIOR RAMUS OF THIRD CERVICAL 

 NERVE 



Profunda cervicis artery 



POSTERIOR RAMUS OF FOURTH CERVICAL 



NERVE 



Semispinalis cervicis 



FIG. 608. POSTERIOR CERVICAL PLEXUS. 



tion the nerve gives off several small muscular and communicating branches. 

 The main trunk, after piercing the semispinalis capitis and trapezius muscles, 

 accompanies the occipital artery to the scalp as the greater occipital nerve. This 

 is the chief cutaneous nerve for the posterior part of the scalp. It enters the 

 superficial fascia at the level of the superior nuchal line of the occipital bone and 

 about an inch from the external occipital protuberance. Bamifying over the 

 surface, it supplies the skin of the scalp as far as the vertex. It communicates on 

 the scalp with the following nerves : great auricular, lesser occipital, posterior 

 auricular, and third occipital. 



The muscular branches of the second cervical nerve are destined for the semi- 

 spinalis capitis, obliquus inferior, semispinalis cervicis, and multifidus. 



Its communicating branches form the posterior cervical plexus. Descending over 

 the posterior arch of the atlas is a branch from the sub-occipital nerve which forms a loop 

 or network with a branch of the second nerve. From this loop twigs are supplied to the 

 surrounding muscles. A similar loop is formed by a communication between branches 

 of the second and third nerves, from which muscles are also supplied. Occasionally an 

 additional loop is formed between branches of the third and fourth nerves. 



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