NERVES 179 



the middle of which there is sometimes found a coccygeal 

 ganglion or ganglion impar. 



Branches are given from the ganglia to the pelvic plexus, 

 and to the middle sacral plexus. 



THE PREVERTEBRAL PLEXUSES OF THE SYMPATHETIC. 



The CARDIAC PLEXUS lies against the aorta and pulmonary 

 artery. It is divided into two parts, superficial and deep. 



The superficial cardiac plexus lies in concavity of the arch 

 of the aorta on the right of the ductus arteriosus. It is com- 

 posed of the left upper cardiac nerve of the sympathetic, the 

 lower cervical cardiac of the left vagus nerve, and branches 

 from the deep plexus. In the plexus is the small ganglion oj 

 Wrisberg. The plexus gives branches to the anterior pul- 

 monary plexus of the left side, and ends in the right coronary 

 plexus which accompanies the right coronary artery. 



The deep cardiac plexus lies between the arch of the aorta 

 and the trachea. It consists of right and left halves united 

 by branches. The right half lies above the right branch of 

 the pulmonary artery; the left half lies on the left of the 

 trachea, close to the ductus arteriosus. 



Afferent branches : 



a. All the cardiac branches from the cervical ganglia 



of the sympathetic, except the left upper nerve. 



b. All the cardiac of pneumogastrics and recurrent laryn- 



geals, except the lower cervical cardiac of the left 

 vagus. 



Efferent branches from the right side join the superficial cardiac 

 plexus to form the right coronary plexus, and others are 

 distributed to the right auricle. 



Efferent branches of the left side mostly end in the left coronary 

 plexus, which accompanies the left coronary artery, and in 

 the superficial cardiac plexus. 



The SOLAR PLEXUS is the largest prevertebral plexus. It 

 lies behind the pancreas and inferior vena cava, in front of the 

 aorta and crura of the diaphragm. It surrounds the origin 

 of the coeliac axis, extending laterally to the supra-renal 

 bodies. It receives the large and small splanchnic nerves 

 and part of the right pneumogastric. It contains several 

 ganglia, and branches are given off from it to accompany the 

 bloodvessels to the viscera, and to form secondary plexuses 

 on these arteries. 



The semilunar ganglia, one in each half of the solar plexus, 

 lie on the inner side of the supra-renal bodies, the left one 



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