146 



XXV, N. LUMBAL.5 



XXVI. N. SACR. I. 1 



XXVU. N. SACR. 



XXVm N. SACR. 3 



XXIX. N. SACR. 



XXX. N SACR. 5. 



Dura 

 mater 



FiL termin. 



490. The Lower 



Extremity of the Spinal 



Cord. 



After Fr. Arnold. 



Spinal Nerves. 



The first cervical nerve emerges be- 

 tween the occipital bone and atlas as sub- 

 occipital nerve; the eighth through 

 the intervertebral foramen between the 

 7. seventh cervical and .first dorsal vertebra. 

 The anterior divisions of the cervical nerves 

 pass in front of or between the bundles 

 of the M. scalenus medius and M. levator 

 scapulae, forwards and outwards; the four 

 upper form the cervical plexus, Plexus 

 cervicalis, the four lower with the greater 

 portion of the first dorsal, the brachial 

 plexus, Plexus brachialis. . The poste- 

 rior division of the first cervical nerve, 

 the infraoccipital nerve, supplies 

 the posterior straight and oblique muscles 

 of the head, the M. bivcnter cervicis and 

 M. complcxus. The posterior division 

 of the second cervical nerve supplies the 

 muscles of the neck (with the exception of 

 the trapezius), and passes as great occi- 

 . p i t a 1 nerve, N. occipitalis maynus, to the^ 

 skin at the back of the head. 



The branches of the cervical plexus are: 



1. Three or four filaments to the upper 

 cervical ganglion of the sympathetic nerve. 



2. Filaments to the ganglion of the 

 trunk of the pneumogastric, to the hypo- 

 glossal and its branch, the Descendens noni, 

 as Ansa In/poglossi. 



3. Filaments to the spinal accessory 

 nerve. 



4. Branches for the following muscles: 

 Scaleni, Lonyus colli, Rectus capit. ant. major 

 et minor and Levator scapulae. 



5. N. occipitalis minor, which ascends 

 along the posterior border of the sterno- 

 cleido-mastoid muscle to the back of the 

 head ; it communicates with the great occi- 

 pital nerve and deep auricular branch of 

 the facial nerve. 



6. -A", auricular is maynus, which emerges 

 at about the middle of the posterior mar- 

 gin of the M. sterno-cleido-mastoideus, ascends 

 upon that muscle to the parotid gland, and 

 divides into an auricular branch, 

 1{. auricularis, and a mas to id branch, 

 It. mastoideus. 



