378 THE SYMPATHETIC NERVES. 



penetrate its substance. Other filaments from the prostatic nerves reach the same 

 structure. 



Prostatic plexus. The nerves of this plexus are of considerable size, and pass 

 between the prostate gland and the levator ani. Some are furnished to the prostate 

 and to the vesicula seminalis ; and the plexus is then continued forwards to supply 

 the erectile substance of the penis, where its nerves are named cavernous. 



Cavernous nerves of the penis. These are very slender, and difficult to dissect. 

 Continuing from the prostatic plexus, they pass onwards beneath the subpubic arch 

 and through the muscular structure connected with the membranous part of the 

 urethra, to the dorsum of the penis. At the root of the latter, the cavernous nerves 

 are joined by some short filaments from the pudic nerve. Having distributed twigs 

 to the fore part of the prostate and the membranous part of the urethra, these nerves 

 divide into branches for the erectile substance of the penis, as follows : 



The small cavernous nerves perforate the fibrous covering of the corpus caver- 

 nosum near the root of the penis, and end in the erectile substance. 



The large cavernous nerve extends forwards on the dorsum of the penis, and 

 dividing, gives filaments which penetrate the corpus cavernosum, and pass with or 

 near the cavernous artery. As it continues onwards, this nerve joins with the 

 dorsal branch of the pudic nerve about the middle of the penis, and is distributed to 

 the corpus cavernosum. Branches from the foregoing nerves reach the corpus 

 spongiosum urethras. The cavernous nerves are composed mainly of pale fibres. 



Vaginal nerves. The nerves furnished to the vagina leave the lower part of 

 the pelvic plexus that part with which the spinal nerves are more particularly 

 combined. They are distributed to the vagina without previously entering into a 

 plexiform arrangement ; and they end in the erectile tissue on the lower and 

 anterior part, and in the mucous membrane. 



Nerves of the uterus. These nerves are derived mainly from the lateral 

 fasciculus prolonged to the pelvic plexus from the hypogastric plexus, but some 

 filaments are also added from the third and fourth sacral nerves. They are directed 

 upwards with the blood- vessels, between the layers of the broad ligament, along the 

 side of the organ, and some slender filaments accompany the branches of the uterine 

 artery, but the larger number of the nerves sink directly into the substance of the 

 uterus, penetrating for the most part its neck and the lower portion of its body. 

 They form connections in the broad ligament with the ovarian nerves, and the 

 fundus of the uterus also receives an offset from that plexus. Numerous small 

 ganglia are contained in the plexus by the side of the neck of the uterus, and a 

 cluster of these constitutes the ganglion cervicale of Frankenhfiuser. They appear 

 to be absent in the muscular substance of the organ. One branch continued 

 directly from the common hypogastric 4 plexus, reaches the hinder surface of the body 

 of the uterus above the rest ; and a nerve from the same source ascends to the 

 Fallopian tube. 



The nerves of the gravid uterus have been frequently investigated, with a view to 

 discover if they become enlarged along with the increase in size of the organ. It is 

 ascertained that the increase which takes place is confined, for the most part, to the 

 thickening of the fibrous envelopes of the nerves ; but it is stated also that fibres 

 furnished with a medullary sheath, which in the un impregnated state of the uterus 

 lose that sheath as they proceed to their distribution, in the impregnated condition 

 of the uterus continue to be surrounded with it as they run between the muscular 

 fibres (Kilian). 



