CERVICAL NERVES. 507 



Of the Cervical Nerves. 



The tenth or last pair of the head, commonly called the 

 Sub-occipital, may be arranged with these nerves, because, it 

 arises, like them, from the medulla spinalis, and is distributed 

 to the muscles on the neck. If counted with the cervical 

 nerves it will make eight pair to the neck. 



The Sub-occipital Nerves 



Arise on each side of the spinal marrow, nearly opposite to 

 the interval between the great foramen of the os occipitis and 

 the atlas. 



Each of these nerves consists of an anterior and posterior 

 fasciculus, or bundle of fibres, which pass outwards immedi- 

 ately under the vertebral arteries between the os occipitis and 

 the atlas, and form a ganglion, from which proceed an anterior 

 and a posterior branch. 



The anterior branch is united to the second cervical nerve 

 below, and to the ninth nerve, or the hyoglossal, above. It 

 also sends filaments to the upper ganglion of the great sympa- 

 thetic nerve. 



The posterior branch is spent upon the Recti, the Obliqui } 

 and some other muscles of the head. 



The proper Cervical Nerves consist of seven pairs ; of which 

 the first six go off between the vertebrae of the neck, and the 

 seventh between the last of the neck and the first of the back. 



The First Cervical Nerve, 



Passes out between the atlas and the Vertebra Dentata. It 

 originates from two fasciculi, which are connected to each 

 other at a ganglion, and then separate into an anterior and a 

 posterior branch.* 



The anterior branch is connected by filaments with the 

 accessory nerve, with the ninth pair of the head, and with 

 the upper ganglion of the sympathetic. It is also connected 



* This arrangement is common to the nerves of the spine. The ganglion is 

 formed in all the spinal nerves by the posterior fasciculus. 



