372 THE SYMPATHETIC NERVES. 



(I) The chief motor fibres of the bladder, distributed probably to the longitudinal 

 muscle. 



(c) Motor fibres of the uterus. 



((I) Vaso-dilator fibres of the penis (nrrri eriyentex). 



(e) Secretory fibres of the prostate gland. 



THE GREAT PLEXUSES OF THE SYMPATHETIC. 



Under this head are included certain large plexuses of nerves placed farther 

 forwards in the visceral cavity than the gangliated cords, and furnishing branches 

 to the viscera. The principal of these plexuses are the cardiac, the solar, and 

 the hypogastric with the pelvic plexuses prolonged from it. They are composed of 

 assemblages of nerves, or of nerves and ganglia, and from them smaller plexuses are 

 derived. 



CABDIAC PLEXUS. 



This plexus receives the cardiac branches of the cervical ganglia and those of the 

 pneumo-gastric nerves, and from it proceed the nerves which supply the heart, 

 besides some offsets which contribute to the nervous supply of the lungs. It lies 

 against the aorta and pulmonary artery, where these vessels are in contact, and in its 

 network are distinguished two parts, the superficial and the deep cardiac plexuses, 

 the deep plexus being seen behind the vessels, and the superficial more in front, but 

 both being closely connected. The branches pass from these plexuses chiefly 

 forwards in two bundles, accompanying the coronary arteries. 



Superficial cardiac plexus. The superficial cardiac plexus (fig. 232) lies in 

 the concavity of the arch of the aorta, between the ligament of the ductus arteriosus 

 and the right branch of the pulmonary artery. In it the superficial or upper cardiac 

 nerve of the sympathetic of the left side terminates, either wholly or in part, 

 together with the lower cervical cardiac branch of the left pneumo-gastric nerve. In 

 the superficial plexus a small ganglion, the ganglion of Wrisberg, is frequently found 

 at the point of union of the nerves. Besides ending in the right coronary plexus, 

 the superficial cardiac plexus furnishes laterally filaments along the pulmonary artery 

 to the anterior pulmonary plexus of the left side. 



Deep cardiac plexus. The deep cardiac plexus, much larger than the 

 superficial one, is placed behind the arch of the aorta, between it and the end of the 

 trachea, and above the bifurcation of the pulmonary artery. 



This plexus receives all the cardiac branches of the cervical ganglia of the 

 sympathetic nerve, except the upper cardiac nerve of the left side. It likewise 

 receives the cardiac nerves furnished by the vagus and by the recurrent laryngeal 

 branch of that nerve, with the exception of the left cervical cardiac nerves. 



Of the branches from the right side of the plexus, the greater number descend 

 in front of the right pulmonary artery, and join branches from the superficial part in 

 the formation of the right coronary plexus ; others, passing behind the right 

 pulmonary artery, are distributed to the right auricle of the heart, and a few 

 filaments are continued into the left coronary plexus. 



On the left side, a few branches pass forwards by the side of the ductus arteriosus 

 to join the superficial cardiac plexus, and others descend to the left auricle ; but the 

 great majority end in the left coronary plexus. 



The deep cardiac plexus sends filaments to the anterior pulmonary plexus on each 

 side. 



Coronary plexuses. The right or posterior coronary plexus is derived from 

 both the superficial and deep cardiac plexuses, the filaments by which it arises 

 embracing the root of the aorta. It accompanies the right coronary artery on the 

 heart, sending its branches upwards and downwards to the auricle and ventricle. 



