130 



TOPOGRAPHICAL ANATOMY OF THE 



to the atlanto-occipital joint. Communicating fibres connect it with 

 the last four cerebral nerves and the ventral branch of the first cervical 

 nerve. Numerous fine filaments pass from the ganglion to the pharyn- 

 geal plexus ; and two or three nerves from it form the internal carotid 

 plexus (plexus caroticus interuus), which accompanies the internal 

 carotid artery into the cranium. An external carotid plexus (plexus 

 caroticus externus) is also formed around the artery of this name. 

 From the caudal end of the ganglion proceeds a nerve-cord that soon 

 enters a connective tissue sheath common to it and the vagus nerve. 

 The two nerves were dissected in the neck (page 6). 



A. meningea posterior. 

 N. accessorius. 



A. condyloidea 



M. rectus capitis lateralis. 



Wing of atlas (in section). ,^ 



A. occipitalis (ramus 



descendens) X-^ 



Cranial cervical ganglion. — 



A. occipitalis. 

 1st cervical nerve. 



A. carotis communis. - 



N. accessorius ^ 

 (ramus dorsalis). 

 N. accessorius 

 (ramus ventralis). 

 N. vagus et truncus-,__™_ 

 sympathicus. ^Av'/, 



-Sympathetic nerve. 



-A. carotis interna. 



M. rectus capitis 

 ~~ ventralis 

 — -N. vagus. 



_-A. carotis interna. 



M. longus capitis. 



^-.M. stylopharyngeus. 

 _ J*^i^^__ N. glossopharyngeus. 

 _X;^^_S^,N. liypoglossus. 



Ramus pharyngeus n. vagi. 

 N. laryngeus cranialis. 



Fig. 55. — The arteries and nerves in the region of the atlanto-occipital and 

 atlanto-epistrophic articulations. 



A. OCCIPITALIS. — The whole length of the occipital artery is now 

 open to examination. One of the smaller terminal branches of the 

 common carotid artery, the occipital runs upwards and backwards 

 into the fossa atlantis, crossing the lateral face of the vagus and 

 accessory nerves. In the fossa, it divides into descending and 

 occipital branches, which were dissected with the other structures 

 dorsal to the atlas (page 105). 



The following are the collateral branches of the occipital artery : — 

 (1) A. glandtUce suhmaxillaris superior. — This is a small vessel 

 that supplies blood to the caudal end of the submaxillary gland. 



