1022 



THE MALE REPRODUCTIVE ORGANS 



(fig 620) appearing as the posterior and inferior Itonndarv of a portion of tlie sub- 

 stance of tlie organ, the so-called ' middle lobe.' 



An irregular artery, usually derived from the internal iliac trunk, is sonietiines 

 found running b)' the side of the prostate to reach the dorsum of the penis, and 

 may be the source of dangerous haemorrhage in lateral lithotomy. It rej)laces one 

 or more of the terminal branches of the internal pudic. 



Structure and function. — The ])rostate is invested by a fibro-muscular capsule, 

 derived from the recto-vesieal segment of the pelvic fascia, unstriped muscle exist- 

 ing in largest proportion over its rectal aspect, bet^A'een the ojtposed borders of the 

 levatores ani. The organ itself is composed of muscular and glandular tissue. 

 The muscular element, comprising both striped and unstriped fil)res, represents about 

 one-half of the entire mass. The unstri]ied fil^res embrace the vesical sphincter 

 above, forming with this a ring of great firmness and strength above the urethral 

 orifices of the ejaculatory ducts, and discharging in all probability the function of 

 intercepting the backward flow of the semen and prostatic fluid into the bladder 

 during sexual congress; below this point, the muscle is intermingled with gland 

 tissue and striated fibres. The striped fibres lie chiefly in the anterior wall of the 



Fig. 620. — Semi-diageammatic Sectiox of the Male Pelvis. 



■MIDDLE LOBE' OF PROSTATE ABOVE THE PROSTATIC FISSURE 



SINUS POCULARIS IN PROSTATIC FISSURE 



MUCOUS MEMBRANE OF BLADDER 



INTERNAL URINARY 

 MEATUS 



VASA DEFERENTIA AND VESICUL/€ SEMINALES 

 ANTERIOR WALL OF RECTUM 



CAVITY OF RECTUM WITH FOLD OF 

 KOHLRAUSCH 



Fascia trans- 

 versalis 



Kecto-vesieal 

 fascia 

 Fat in space 

 of Ketzius 



SYMPHYSIS 



Vesico-pubic 

 muscle 



ANTERIOR WALL OF 

 PROSTATE WITH 

 CAPSULE 



Dorsal vein 

 of jii'nis 



SEPTUM PECTINIFORME 



CORPUS SPONGIOSUM 

 URETHR/E 



STERIOR WALL 

 OF PROSTATE 

 WITH CAPSULE 



Seetal por- 

 tion of recto- 

 vesical fascia 



Sphincter ani 



LOWER END OF 



RECTUM 

 Sphincter ani 



Fascia of Colles 

 Deep transversus perinaei between superficial 

 and deep triangular ligaments 



Junction of deep and superficial triangular 

 ligaments with fascia of Colles 



COWPER'S GLAND 



prostate, but completely encircle the apex of the organ, and are there pr(i])ably 

 (•oiinected with the deep transversus perinaei. The mus(;ular fibres of both kinds 

 Ijelow the ejaculatory ducts undoubtedly initiate the forward projuilsion of the 

 mingled prostatic and seminal secretions; the ejaculation being further aided by 

 the contraction of the deep transversus perinsei, and Intlbo-cavernosi. 



The glands are of the branched tul)ular type, and lie chiefly in the jiosterior and 

 lateral i^arts of the organ, their ducts opening into the urethral recesses (prostatic 

 sinuses ) l)y the sides of the verumontanum. They secrete a mucus, the princij^al 

 use of which is to dilute and give bulk to the semen, and they are sometimes the 

 seat of pathological concretions. In addition to the true glands are seen a number 

 of simple follicles in the anterior wall of the prostatic urethra, probably of the 

 same nature as the rest of the urethral follicles. The prostatic urethra will be 

 described hereafter (page 1087). 



The organ is essentially generative, but serves also to reinforce the vesical 

 sphincter, although its absence in the female and its imi)erfect development in chil- 

 dren and eunuchs ap)>ear to entail no defect in th(> control of the bladder. The 

 muscular fibres are, however, to some extent rei)resented in the female (page 1042). 



