1306 



THE UEO-GENITAL SYSTEM. 



of about one-third of an inch. The posterior wall, often termed the " floor " of 

 the prostatic urethra, presents a distinct median ridge or elevation called the 

 crista urethralis (Fig. 1026). This projects forwards into the urethra to such 

 an extent that the canal in transverse section presents a somewhat crescentic 

 outline. In the depressions, or grooves, on each side of the crista urethralis 



Ductus deferens 



Inferior 

 epigastric artery 



Superior peritoneal lig. 



of bladder .-.- 

 Urinary bladder E- 

 Sacro-genital fold 

 Recto-vesical pouch 

 Ductus deferens 

 Retro-pubic pad of fat 

 Prostatic urethra 



Dorsal vein of penis 



Corpus cavernosum penis 



Corpus cavernosum 



urethra 



Anal canal 

 Membranous urethra 

 Cavernous portion of urethra Bulb of urethra 



FIG. 1025. ADULT MALE PELVIS IN MEDIAN SECTION. 

 The urinary bladder is empty and firmly contracted. The urethra is opened up in its entire length. 



the numerous ducts of the prostatic glands open by minute apertures. Some 

 few ducts from the middle part of the gland open nearer the median plane, on 

 the sides of the urethral crest. On the summit of the crista urethralis is 

 a slit -like opening which leads backwards and upwards for a distance of 

 about a quarter of an inch, as a blind pouch, in the substance of the prostate. 

 This little cavity is known as the utriculus prostaticus, and represents the 

 fused posterior ends of the Miillerian ducts, from which the uterus and vagina 

 of the female are developed. The term uterus masculinus is therefore some- 

 times applied to this little pouch. On each side of the mouth of the utricle 

 is the much more minute opening of the ejaculatory duct. When traced upwards 

 towards the bladder, the urethral crest, diminishing in height, becomes indistinct. 



