ANATOMY IN A NUTSHELL. 427 



from the aortic plexus. It distributes branches to half of the transverse colon 

 and the descending colon, to the sigmoid plexus, to the superior hemorrhoidal 



plexus, and to the pelvic plexus. 



LESSON CX XV. 

 Hypogastric Plexus. 



This plexus is situated in front of the promontory of the sacrum between 

 the common iliac arteries. It contains no ganglia. It receives branches from 

 the aortic plexus, the lumbar ganglia. It bifurcates below into two lateral 

 halves which form the pelvic plexuses. This plexus is made up exclusively of 

 sympathetic nerves. 



Pelvic Plexus. 



This is situated at the side of the rectum and bladder in the male, and in 

 the female it is at the side of the rectum, bladder and vagina. It accompanies 

 the branches of the internal iliac artery and supplies the pelvic viscera. This 

 plexus contains small ganglia. It is formed by the two lateral continuations of 

 hypogastric plexus, branches of the sacral part of the gangliated cord, branches 

 of the second, third and fourth sacral nerves. It sends branches of distribution 

 to the middle hsemorrhoidal plexus, the inferior hemorrhoidal plexus, the vesical 

 plexus, the prostatic plexus, the vaginal plexus, and the uterine plexus. 



The middle hsemorrhoidal plexus is situated on the sides of the rectum, and 

 is formed by branches from the pelvic plexus. It communicantes above with 

 the superior hsemorrhoidal plexus and below with the inferior hsemorrhoidal 

 plexus. It is distributed to the rectum. 



The inferior hsemorrhoidal plexus arises from the back part of the pelvic 

 plexus and joins with branches from the superior and middle hsemorrhoidal 

 plexuses. It is distributed to the rectum. 



The vesical plexus arises from the fore part of the pelvic plexus, and is 

 formed chiefly by fibers from the third and fourth sacral nerves. Tin nerves 

 sent off pass on each side of the bladder. This plexus is divided into two 

 groups, (1) superior group, (2) inferior group. It distributes branches to the 

 bladder, the vesiculse seminales, the vas deferens, the spermatic plexus. 



The prostatic plexus is a continuation downward of the pelvic plexus and 

 is situated around the prostate gland. Its nerves are of large size. On the 

 sides of the gland are several ganglionic masses from one-fourth to one-half an 

 inch in length (ganglia prostatica of Muller). It is joined by branches of the 

 internal pudic nerve. It distributes branches to the prostate gland, the ves- 

 iculse seminales, small cavernous nerves to the erectile structure of the penis, 

 corpora caveronsa and corpus spongiosum, barge cavernous nerve joins the 

 dorsal branch of the pudic nerve and supplies the corpora cavernosa and corpus 

 spongiosum. 



The vaginal plexus arises from the lower part of the pelvic plexus and is 

 composed hugely of sacral nerves. It is situated on the sides of the vagina. 

 It gives off branches to the erectile tissue of the vagina, the mucous membrane 

 of the vagina, and a few twigs to the clitoris. 



The uterine plexus arises from the upper pari of the pelvic plexus and ac- 



