380 NEUROLOGY, OR ANATOMY OF NERVOUS SYSTEM 



The pelvic plexuses (inferior hypogastric) lie one on each side of 

 the rectum, and in the female, the vagina. They receive 

 filaments from the second, third, and fourth sacral nerves, 

 and where these join the plexus small ganglia are developed. 

 The nerves from the plexus supply all the pelvic viscera, accom- 

 panying the branches of the internal iliac artery and forming 

 the following secondary plexuses: 



The hemorrhoidal plexus joins the superior hemorrhoidal 

 branches (from the inferior mesenteric plexus) to supply the 

 rectum. 



The vesical plexus contains many spinal nerves, runs with 

 the vesical arteries, and sends nerves along the vas deferens. 



The prostatic plexus consists of large nerves from the lower 

 part of the pelvic plexus, which supply the prostate, seminal 

 vesicles, and cavernous bodies. These latter are divided into 

 the small and large cavernous, and join the pudic branches. 

 The small pierce the fibrous coat near the root of the penis 

 and end in the erectile tissue. The large (single) runs forward 

 on the dorsum, and supplies the corpora spongiosa and corpora 

 cavernosa. 



The vaginal plexus runs in the vaginal walls and mucous 

 membrane. 



The uterine plexus sends some branches along the uterine 

 artery, and others which directly pierce the cervix and lower 

 part of the body. Branches pass also to the ovarian plexus and 

 fundus uteri. 



THE ORGANS OF SPECIAL SENSE 



THE EYE 



The eyeball lies in the fat of the orbit, surrounded by a 

 tunic of fascia, the capsule of Tenon. It is composed of seg- 

 ments of two spheres, an anterior smaller and a posterior 

 larger, the junction of the sclerotic and cornea indicating their 

 limits. It measures one inch transversely and vertically, and 

 somewhat less from before backward. Behind it receives 

 the optic nerve, and in front are the eyelids, eyebrows, etc., 

 which comprise the so-called appendages of the eye. 



