DISSECTING MANUAL. 



on that artery. The internal carotid is an upward prolongation 

 of the ganglion on the internal carotid; it divides into inner 

 and outer parts which form two plexuses around the artery, 

 respectively the cavernous plexus above and the carotid be- 

 low. The carotid plexus communicates with the abducent and 

 the Gasserian ganglion and gives off two large branches ; one 

 (great deep petrosal) joins the great superficial petrosal, of the 

 facial, to form the Vidian; the other (small deep petrosal) enters 

 the tympanic plexus of the glosso-pharyngeal. The cavernous 

 plexus communicates with the oculo-motor, trochlear, and 

 ophthalmic; it supplies the pituitary body and provides the 

 sympathetic root of the ciliary ganglion. [706] 



The middle cervical ganglion lies over the inferior thyroid 

 artery and is small and often absent, its branches arising from 

 the cord. It communicates with the anterior primary divis- 

 ions of the fifth and sixth cervical; and with the inferior 

 cervical ganglion by a loop (subclavian) which passes over 

 the subclavian artery. Branches : The middle cervical cardiac 

 descends behind the great vessels to the thorax. Branches 

 accompany the inferior thyroid artery inward to supply the 

 thyroid body. [708] 



The inferior cervical ganglion lies behind the subclavian ar- 

 tery, between the last cervical transverse process and the neck 

 of the first rib. It communicates with the anterior primary 

 divisions of the seventh and eighth cervical nerves, middle 

 cervical ganglion (by the subclavian loop) , and often with the 

 inferior laryngeal. Branches: The inferior cervical cardiac 

 descends to the thorax. It also forms two plexuses, vertebral 

 and subclavian, on those arteries; the branches forming the 

 latter arise from the subclavian loop. [708] 



ARTERIES. 



Common Carotid. This runs in the carotid sheath, internal 

 to the internal jugular, from the sterno-clavicular joint to the 

 lower border of the third cervical vertebra, at the level of the 



[78] 



