Relations of Prostate 



413 



), surrounding its neck. It is shaped like the ace of hearts, the 

 apex pointing against the triangular ligament. It is about the size of 

 a horse-chestnut, and consists of two lateral lobes and an intermediate 

 portion. The urethra runs through it, but nearer to the upper sur- 

 face. Additional relations are these : The pubic symphysis lies above 

 and in front. Behind, in addition to the bladder, are the vesiculae 

 seminales and the vasa deferentia. Close below and behind is the 

 rectum, through which the index finger can define much of its outline. 

 Below it is the thick mass of the perineum. (See fig. on p. 385.) 



9 8 44 



1120 



i, pubes ; 5, pubo-prostatic ligament ; 9, middle lobe of, 10, prostate ; 12, left vas ; 13, left 

 vesicula ; 14, com. ejaculatory duct ; 16, prostatic plexus receiving 17, dorsal vein of 

 penis ; 19, bulb ; 20, Cowper's gland. 



Investments. A fibrous capsule immediately surrounds the pro- 

 static tissue, and sends processes into its substance, being, indeed, 

 part of the gland. On the outside of this is a plexus of veins, which 

 is in communication with the veins of the bladder and rectum (vesico- 

 prostatic plexus) ; and at the front the plexus receives the dorsal vein 

 of the penis. This large venous plexus separates the fascial invest- 

 ment of the prostate from the fibrous coat of the gland. The veins 

 are often dilated, and occasionally contain calcareous matter ; they are 

 divided in lateral lithotomy, and then, in the adult, may be the source 

 of serious bleeding. 



