THE CERVICAL SY .W/M THI'.TK' <;.\\'<iUA l(>i>:> 



given off by the superior cervical sympathetic ganglion. 'I'lic cephalic ganglia are 

 all relatively small. There are four considered in tin- onlinary macroscopic dissec- 

 tions, namely, the ciliary or ophthalmic, the spheno-palatine or Meckel's ganglion, 

 the otic, and the sul. maxillary. The-e ganglia with their roots or communicating 

 branches have been described in detail in their connections with the divisions of the 

 trigeminus and with the oculo-motor and facial nerves. 



The internal carotid nerve, the ascending branch from the superior cervical 

 sympathetic ganglion, may be regarded as an upward prolongation of the primitive 

 sympathetic, trunk. It arises from the upper end of the superior cervical ganglion 

 and pas>es through the carotid canal into the cranial cavity. It divides into two 

 branches which subdivide to form a coarse plexus, the internal carotid plexus, which 

 partly surrounds the internal carotid artery before the latter enters the cavernous 

 sinus dig. 719). It passes with the artery to the cavernous sinus, where it forms 

 the liner meshed niiTrniinn /ilr.nts. 



The internal carotid plexus supplies offsets to the artery and receives communi- 

 cating branches from the tympanic plexus through the inferior carotico-tympanic 

 nerve and from the spheno-palatine ganglion through the great deep petrosal nerve. 

 It also communicates by line branches with the semilunar (Gasserian) ganglion and 

 with the sixth cranial nerve. 



The cavernous plexus gives branches of communication to the oculo-motor and 

 trochlear nerves and to the ophthalmic division of the trigeminus. According to 

 Toldt and Spalteholz, it communicates with the tympanic plexus through the 

 superior carotico-tympanic (small deep petrosal) nerve. It also communicates with 

 the ciliary ganglion through the long root of the ciliary ganglion. These branches 

 may pass through the superior orbital (sphenoidal) fissure either separately or with the 

 naso-ciliary (nasal) nerve. 



The cavernous plexus also gives branches to the carotid artery and filaments of the 

 plexus accompany small branches of the artery to the hypophysis (pituitary body) and 

 to the dura mater on the sphenoid bone. 



The terminal branches of the cavernous plexus consist of delicate filaments that 

 anastomose freely, forming fine plexuses, and pass from the cavernous plexus along 

 the terminal divisions of the internal carotid artery and their branches. These fine 

 plexuses take the name of the artery on which they lie. The four larger of them are 

 the plexuses of the anterior and middle cerebral arteries, the plexus of the chorioid 

 artery, and the ophthalmic plexus. 



The cervical portion of the sympathetic cord extends upwards along the great 

 vessels of the neck. No white rami communicantes connect it directly with the spinal 

 cord, but instead it receives splanchnic efferent fibres from the upper thoracic spinal 

 nerves through the sympathetic trunk, and probably also from the cervical spinal 

 cord through the spinal accessory nerve and the connections with the vagus. It 

 sends grey rami communicantes to each of the cervical nerves. It extends from the 

 subclavian artery to the base of the skull, lying behind the sheath of the great vessels 

 and in front of the longus capitis and longus colli, which separate it from the trans- 

 verse processes of the cervical vertebrae (fig. 719). It usually has but three ganglia, 

 one at each end, the superior and inferior, and one between these two, called the 

 middle ganglion. The latter varies somewhat in position and is sometimes absent. 



SUPERIOR CERVICAL GANGLION 



The superior cervical ganglion is usually fusiform in shape and is sometimes 



marked by one or more constrictions. There is ground for the belief that it is formed 

 by the coalescence of four ganglia corresponding to the first four cervical nerves. 

 It varies from an inch to one and one-half inches (2'5 to 3'7 cm.) in length, lying 

 behind the upper part of the sheath of the great vessels of the neck and in front of the 

 transverse processes of the second and third cervical vertebrae. It occasionally ex- 

 tends upwards as high as the transverse process of the first vertebra (fig. 719). It 

 is connected with the middle cervical ganglion by the intervening trunk, and it 

 gives off a large number of communicating 1 'ranches. 



Communications : (1) Four grey rami communicantes connect the ganglion 

 with the anterior primary divisions of the first four cervical nerves. 



(2) Communicating branches to the cranial nerves. An irregular number 

 of small twigs pass from the superior cervical ganglion to the hypoglossal nerve 



