874 THE NERVOUS SYSTEM. 



Pelvic Portion of the Gangliated Cord. 



The pelvic portion of the gangliated cord is situated in front of the sacrum 

 along the inner side of the anterior sacral foramina. It consists of four or five 



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small ganglia on each side, connected together by interganglionic cords. Below, 

 these cords converge and unite on the front of the coccyx by means of a small 

 ganglion (the coccygeal ganglion or ganglion impar). 



The superior and inferior branches are the cords of communication between the 

 ganglia above and below. 



The external branches, exceedingly short, communicate with the sacral nerves. 

 They are two in number from each ganglion. The coccygeal nerve communicates 

 either with the last sacral or coccygeal ganglion. 



The internal branches communicate, on the front of the sacrum, with the 

 corresponding branches from the opposite side ; some, from the first two ganglia, 

 pass to join the pelvic plexus, and others form a plexus which accompanies the 

 middle sacral artery and sends filaments to the coccygeal gland. 



THE GREAT PLEXUSES OF THE SYMPATHETIC. 



The great plexuses of the sympathetic are the large aggregations of nerves 

 and ganglia, above alluded to, situated in the thoracic, abdominal, and pelvic 

 cavities respectively. From them are derived the branches which supply the 

 viscera. 



The Cardiac Plexus. 



The cardiac plexus is situated at the base of the heart, and is divided into a 

 superficial part, which lies in the concavity of the arch of the aorta, and a deep 

 part, which lies between the trachea and aorta. 



The great or deep cardiac plexus (plexus magnus profundus, Scarpa) is 

 situated in front of the trachea at its bifurcation, above the point of division of 

 the pulmonary artery and behind the arch of the aorta. It is formed by the 

 cardiac nerves derived from the cervical ganglia of the sympathetic and the 

 cardiac branches of the recurrent laryngeal and pneumogastric. The only cardiac 

 nerves which do not enter into the formation of this plexus are the left superior 

 cardiac nerve and the left inferior cervical cardiac branch from the pneumogastric. 



The branches from the right side of this plexus pass, some in front of, and 

 others behind, the right pulmonary artery ; the former, the more numerous, 

 transmit a few filaments to the anterior pulmonary plexus, and are then continued 

 onward to form part of the anterior coronary plexus ; those behind the pulmonary 

 artery distribute a few filaments to the right auricle, and are then continued 

 onward to form part of the posterior coronary plexus. 



The branches from the left side of the deep cardiac plexus distribute a few 

 filaments to the superficial cardiac plexus, to the left auricle of the heart, and to 

 the anterior pulmonary plexus, and then pass on to form the greater part of the 

 posterior coronary plexus. 



The superficial (anterior) cardiac plexus lies beneath the arch of the aorta, in 

 front of the right pulmonary artery. It is formed by the left superior cardiac 

 nerve, the left (and occasionally the right) inferior cervical cardiac branches of the 

 pneumogastric, and filaments from the deep cardiac plexus. A small ganglion 

 (cardiac ganglion of Wrisberg] is occasionally found connected with these nerves 

 at their point of junction. This ganglion, when present, is situated immediately 

 beneath the arch of the aorta, on the right side of the ductus arteriosus. The 

 superficial cardiac plexus forms the chief part of the anterior coronary plexus, and 

 several filaments pass along the pulmonary artery to the left anterior pulmonary 

 plexus. 



The posterior coronary plexus is chiefly formed by filaments prolonged from 

 the left side of the deep cardiac plexus, and by a few from the right side. It 

 surrounds the branches of the coronary artery at the back of the heart, and its 



