1126 



SURGICAL AXD TOPOGRAPHICAL AX ATOMY 



The prostate (figs. 692 and 694). — The ivlations of this important organ 

 should be studied, whenever possible, with the finger and sound. Koughly eonii»ar- 

 able to a chestnut in form, size, and dimensions, its base, situated below the neck 

 of the l)ladder, blends by its muscular tissue with this organ. As the long axis of 

 the })rostate is very obli(iue, the base will be directed upwards and backwards (fig. 

 694). The apex, resting against the upper or deeper layer of the triangular liga- 

 ment, lies about half an inch behind the sul)pubic angle. This part of the organ 

 can be detected by the finger about one and a half inches above the anal orifice, 

 through the anterior wall of the rectum. Continuous Avith tliis. and a little higher 

 up, the posterior surface can also be made out througli the second part of the 

 bowel. The anterior surface receives the pul>o-prostatic ligaments, and on this 

 surface lies the greater part of the prostatic plexus (fig. 696). The lateral margins 

 of the gland are embraced b}' the anterior borders of the levatores ani. The urethra, 

 in its course through the organ from base to apex in the middle line, lies rather 

 nearer to the anterior than the posterior surface. The ejaculatory ducts, as they 

 pass obliquely through the prostate to open at the margins of the sinus i^ocularis, 

 mark off a portion of the gland which lies between each duct lielow and the neck 

 of the bladder above (fig. 694). It is obvious tliat, if this portion be enlarged, 



Fig. 690. — Scheme of the Pidic Artery axp its Branches. 



Subpubic ligament with aperture for 

 dorsal vein of the penis 



Apertures for dorsal nrlery and ( 

 nerve of the penis \ 



Crus penis 

 Aperture for artery of cur pas 

 carernosum 

 Superficial triangular ligament 

 lachio-eavernosuB, or erector penis 

 Aperture for artery 

 to bulb 

 Urethral aperture 

 Aperture for Cow- 

 per's duet 

 Position of bulb 



Apertures for super- 

 ficial perinceal 

 vessels and nerve 



Fascia of Colles, 

 turned backwards 



DORSAL NERVE 



.r^—. Anterior layer of triangular 

 "% ligament 



-S- Dursal artery of penis 



Vi Deep triangu- 

 lar ligament 

 Artery of curjius 

 cavernosuin 



A riery to bulb 



iidic veins 

 DORSAL NERVE 



POSITION OF COWPER'S 

 GLAND 



Internal pudic artery 



Posterior border of 

 perinaeal ledge 

 'junction of trian- 

 gular ligaments 

 with fascia of 

 Collesj 



obstruction to the escape of urine from the bladder nuist follow. Up to puberty, 

 the prostate is imperceptible per rectum. In adolescence the organ, while to be 

 felt, is softer and more rounded, and lacks the character and shape which distinguish 

 the organ in adult life. The capsule (fig. 696) of the organ must be rememl)cred. 

 It is formed l)y a layer from the recto-vesical fascia, and under it, es]iecially on its 

 anterior and lateral asi)ects (fig. 696), lies the jn-ostatic plexus, formed chiefly by 

 the breaking up of the dorsal vein of the penis. 



The continuity of the above sheath of the i)rostate with the recto-vesical fascia 

 on the upper surface of the levator ani and the sides of the bladder forms the roof 

 of the perinaeum and part of the floor of the pelvis. If by mistake an incision, as 

 in lithotomy, is carried through this prostatic sheath, the cavities of the pelvis Avill 

 l)e opened and extravasation of fluids into the connective tissue, which everywhere 

 follinvs the layers of ])elvic fascia, will follt)w. Before leaving the relations of the 

 prostate, the render should consider the layers which will be met with in 

 cutting down to this organ from the surface. The f(»llo\\ing fascia' and mus- 

 cular layers will be met with alternately (Cunningham): (1) Skin and superiicial 

 fascia; (2) fascia of Colles; (3) superficial perina-al muscles; (4) superficial layer 

 of triangular ligament; (5) compressor uretln-a'; (6) deep layer of triangular liga- 



