CERVICAL PORTION OF THE GANGLIA TED CORD. 869 



In addition to these various divisions of the sympathetic, the ganglia con- 

 nected with the three branches of the fifth cranial nerve are believed by some 

 to constitute a part of the sympathetic system. These ganglia have already been 

 described (page 799 et seq.). 



THE GANGLIATED CORD. 

 Cervical Portion of the Gangliated Cord. 



The cervical portion of the gangliated cord consists of three ganglia on each 

 side, which are distinguished, according to their position, as the superior, middle, 

 and inferior cervical. 



The Superior Cervical Ganglion, the largest of the three, is placed opposite the 

 second and third cervical vertebrae, and sometimes as low as the fourth or fifth. It 

 is of a reddish-gray color, and usually fusiform in shape, sometimes broad, and 

 occasionally constricted at intervals, so as to give rise to the opinion that it consists 

 of the coalescence of several smaller ganglia ; and it is usually believed that it is 

 formed by the coalescence, of the four ganglia, corresponding to the four upper 

 cervical nerves. It is in relation, in front, with the sheath of the internal carotid 

 artery and internal jugular vein; behind, it lies on the Rectus capitis anticus 

 major muscle. 



Its branches may be divided into superior, inferior, external, internal, and 

 anterior. 



The superior branch appears to be a direct prolongation of the ganglion. It 

 is soft in texture and of a reddish color. It ascends by the side of the internal 

 carotid artery, and, entering the carotid canal in the temporal bone, divides into two 

 branches, which lie, one on the outer, and the other on the inner, side of that vessel. 



The outer branch, the larger of the two, distributes filaments to the internal 

 carotid artery and forms the carotid plexus. 



The inner branch also distributes filaments to the internal carotid, and, con- 

 tinuing onward, forms the cavernous plexus. 



The Carotid Plexus. 



The carotid plexus is situated on the outer side of the internal carotid. Fila- 

 ments from this plexus occasionally form a small gangliform swelling on the under 

 surface of the artery, which is called the carotid ganglion. The carotid plexus 

 communicates with the Gasserian ganglion, with the sixth nerve, and the spheno- 

 palatine ganglion, and distributes filaments to the wall of the carotid artery and 

 to the dura mater (Valentin), while in the carotid canal it communicates with 

 Jacobson's nerve, the tympanic branch of the glosso-pharyngeal. 



The communicating branches ivith the sixth nerve consist of one or two fila- 

 ments which join that nerve as it lies upon the outer side of the internal carotid. 

 Other filaments are also connected with the Gasserian ganglion. The communi- 

 cation with the spheno-palatine ganglion is effected by a branch, the large deep 

 petrosal, which is given off from the plexus on the outer side of the artery, and 

 which passes through the cartilage filling up the foramen lacerum medium, and 

 joins the great superficial petrosal to form the Vidian nerve. The Vidian nerve 

 then proceeds along the pterygoid or Vidian canal to the spheno-palatine ganglion. 

 The communication with Jacobson's nerve is effected by two branches, one of 

 which is called the small deep petrosal nerve, and the other the long petrosal. 



The Cavernous Plexus. 



The cavernous plexus is situated below and internal to that part of the internal 

 carotid which is placed by the side of the sella Turcica in the cavernous sinus, 

 and is formed chiefly by the internal division of the ascending branch from the 

 superior cervical ganglion. It communicates with the third, the fourth, the 

 ophthalmic division of the fifth, and the sixth nerves, and with the ophthalmic 



