THE MALE URETHRA 



13G9 



Crest of the. 

 urethra. 

 Verumon- 

 t an um. 



Prostate. 



internal orifice of the urethra and the deep layer of the triangular ligament and 

 lies within the pelvic cavity. It passes almost vertically through the prostate 

 gland from its base to its apex, lying nearer its anterior than its posterior surface. 

 The gland seems to completely surround this portion of the urethra (Fig. 1149), 

 but the glandular substance proper does not (Fig. 1152). The gland is like a 

 clasp open in front, and the open part of the clasp is closed by the prostatic muscle. 

 The form of the canal is spindle-shaped, being wider in the middle than at either 

 extremity, and narrowest below, where it joins the membranous portion. Except 

 during the passage of fluid, the canal is in a collapsed state and is horseshoe-shaped 

 on trans-section, the anterior wall resting 

 upon the posterior wall (Fig. 1120), and 

 the mucous membrane exhibiting longi- 

 tudinal folds. When distended, the largest 

 portion of the prostatic urethra in the cad- 

 aver has a diameter of about one-half inch 

 (12 mm.). 



Upon the posterior wall or floor of the 

 canal is a narrow longitudinal ridge, the 

 verumontanum or caput gallinaginis (Figs. 

 1119 and 1154) (crista urethralis], formed 

 by an elevation of the mucous membrane 

 and its subjacent tissue (Fig. 1153). It is 

 about 16 mm. in length and about 3 mm. 

 in height, and contains, according to Kobelt, 

 muscle and erectile tissues. On either 

 side of the verumontanum is a slightly 

 depressed fossa, the prostatic sinus, the floor 

 of which is perforated by numerous aper- 

 tures, the orifices of the prostatic ducts 

 (Figs. 1119 and 1154), from the lateral lobes 

 of the glands; the ducts of the middle lobe 

 open behind the verumontanum. At the 

 fore part of the verumontanum, in the 

 middle line, is a depression, the sinus 

 pocularis (utriculus prostaticus] (Figs. 339 

 and 1154), upon the margins of which are 

 the slit-like openings of the ejaculatory ducts 

 (Fig. 1154). The sinus pocularis forms a 

 cul-de-sac about a quarter of an inch in 

 length, which runs upward and backward 

 in the substance of the prostate into the 

 so-called middle lobe; its prominent ante- 

 rior wall partly forms the verumontanum. 

 Its walls are composed of fibrous tissue, 

 muscle fibres, and mucous membrane, and numerous small glands open on its 

 inner surface. It has been called the uterus masculinus, because it is developed 

 from the united lower ends of the atrophied Miillerian ducts, and therefore is 

 homologous with the uterus and vagina in the female. 



The membranous portion (pars membranacea) (Figs. 1111 and 1119) lies 

 between the two layers of the triangular ligament, and extends downward and for- 

 ward between the apex of the prostate and the bulb of the corpus spongiosum. 

 It is the narrowest part of the canal (excepting the meati), has a calibre of about 

 one-third of an inch (8 mm.), and measures about half an inch (10 to 12 mm.) 

 in length. Its anterior concave surface is placed about an inch below and behind 



Glans. 



Meatus. 



FIG. 1119. The male urethra, laid open on its 

 anterior (upper surface.) (Testut.) 



