420 A MANUAL OF ANA TOMY. 



It receives the two veins of divisions of the dorsal vein of 

 the penis, the veins of the prostate and bladder, communi- 

 cates with the hemorrhoidal plexus, and empties by a right 

 and left branch into the corresponding internal iliac vein. 



The Vesical Plexus 



Is formed by the veins which surround the bladder and at 



its base empty into the prostatic plexus. 



In the female, the vaginal plexus surrounds the vagina 

 and opens into the hemorrhoidal and vesical plexuses. 

 The uterine plexus terminates in the ovarian veins. 



Base of the Bladder. See page 537. 



The external trigxme (Fig. 84) is the surface of the bladder 

 included between the diverging vasa deferentia and the peri- 

 toneal reflection from the bladder to the rectum, which is from 

 one to one and one-half inches from the base of the prostate. 



The Seminal Vesicles. Fig. 84. 



These are two in number, two inches long, one-half inch 

 wide, one-quarter inch thick, situated outside the vas 

 deferens, one and one-quarter inches above, and, like the 

 vas, inclining downward and inward to the prostatic notch 

 to empty into the common duct. Their function is the 

 storage of the seminal fluid. 



Relations. Behind is the rectum ; in front, the bladder 

 and termination of the ureters ; internally, the vas deferens ; 

 below, the prostate. They are enclosed in a capsule from 

 the rectovesical fascia. When unraveled each vesicle is 

 found to consist of a single tube about four inches long, 

 with numerous blind outgrowths. 



Vas Deferens. See page 542. 



The Prostate. Fig. 84. Diags. 27, 28. 



This is a fibromuscular gland surrounding the neck of 

 the bladder and the beginning of the urethra. It is heart- 



