THE MALE URETHRA 



1263 



In its course (fig. 1024) it traverses first the prostate gland, then the urogenital 

 diaphgram and then the entire length of the corpus cavernosum urethrge, and may 

 thus be regarded as being composed of three portions. 



The prostatic portion [pars prostatica] (fig. 1024) extends almost vertically 

 downward from the neck of the bladder, traversing the substance of the prostate 

 gland. In its proximal part there is on its posterior wall a median longitudinal 

 ridge, the crista urethralis, which below dilates into an oval enlargement, the 

 colliculus seminalis (figs. 1015, 1025), to accommodate which there is a marked 



Fig. 1025. — The Male Urethra, cleft anterioim y to ^ho\v the Mucous Coat. 



Section of bladder 



Section of prostate 

 Colliculus seminalis 

 Ejaculatory duct 

 Openings of prostatic glands 



Follicular glands of dorsal wall 



Membranous uerthra 



Section of corpus cavernosum penis 



Thin layer of corpus 

 cavernosum urethras 



Orifice of bulbo-urethral gland 



Section of corpus cavernosum penis 



Bulbous portion of urethra 



Mucous membrane 



( 



Fossa navicularis 



' External urethral orifice 



widening of the lumen of the urethra in this part of its course. At the centre of 

 the colliculus there is an elongated opening of a pouch of varying depth,termed the 

 utriculus prostaticus (''uterus mascuKnus"), which corresponds to the lower part 

 of the vagina in the female (see p. 1279). Situated one on either side of this are 

 the much smaller openings of the ejaculatory ducts. Owing to the prominence 

 formed by the colliculus a section of the urethra in this region is somewhat 

 n-shaped, and at the bottom of the furrows on either side of the median eleva- 



