412 



DISSECTION OF THE PELVIS. 



divided, as already stated (pp. 389 and 390) into prostatic 

 membranous and spongy parts. 



How to open Dissection. To open the urethra, let the incision through the 

 prostate be continued onwards to the extremity of the penis along 

 the dorsal surface, passing as accurately as possible in the septum 

 between the two corpus cavernosum. 



The prostatic part (figs. 153 and 154) is nearer the anterior 

 than the posterior surface of the mass surrounding it. It is one 

 inch and a quarter in length, and is the widest portion of the 

 urethral canal. Its form is spindle-shaped, for it is larger in the 

 middle than at either end. Its transverse measurement at the neck 

 of the bladder is nearly a third of an inch ; at its centre a line or 

 two more ; and at the lower end rather less than at the beginning. 



the urethra. 



Prostatic 

 part: 



dimensions 

 and 



shape ; 

 diameter. 



FIG. 153. SECTION THROUGH THE BLADDER, PROSTATE, AND URETHRA, TO 

 SHOW THE VESICULA PROSTATICA AND THE COMMON SEMINAL DUCT. 



a. Bladder. 



b. Prostate. 



c. Prostatic part of urethra. 



d. Vesicula seminalis. 



e. Vas deferens. 

 /. Common ejaculatory duct. 

 g. Uterus masculinus ; above this 

 is the middle lobe of the prostate. 



On the floor 

 is a crest : 



Separating the prostatic portion of the urethra from the bladder 

 ^e eminence known as the uvula vesicse. Beginning half an 

 inch below this is a central longitudinal eminence of the mucous 

 lining of the prostatic urethra (fig. 154, d), about three-quarters of 

 an inch in length, and larger above than below, which is prolonged 

 towards the membranous part of the canal, and is named crest of the 

 urethra (verumontanum, caput gallinaginis) : it is formed of erectile 

 substance, with a framework of elastic and muscular tissues. In 

 the crest of the mucous membrane, near its posterior extremity, is 

 in the crest the opening of the uterus masculinus or utriculus (sinus pocularis 

 or vesicula prostatica). 



The uterus masculinus (fig. 153, </) is a blind passage directed 

 the J prostate backwards in the prostate, from a quarter to half an inch, passing 

 beneath the middle and between the lateral lobes. The student 



is a pouch. 

 Vesicula 



