PRACTICAL CONSIDERATIONS : PROSTATE GLAND. '979 



Development. At about the third month of foetal life the wall of the primitive 

 urethra undergoes thickening-, leading to the production of an annular mass of meso- 

 blastic tissue that surrounds the lower ends of the Wolffian and Miillerian ducts 

 (later the ejaculatory ducts and the prostatic utricle respectively) and subsequently 

 becomes differentiated largely into unstriped muscle. Into this penetrate solid epi- 

 thelial outgrowths, from the lining of the urethra, which expand into branched cylinders 

 that give rise to the prostatic glandular tissue. These outgrowths are arranged in 

 three groups (Pallin), a ventral, an upper and a lower dorsal. The ventral group 

 gives rise to the glandular tissue in front of the urethra, which at first is relatively 

 abundant, but soon suffers reduction, and in the adult organ is often almost wanting. 

 The dorsal groups produce the important glands of the median and lateral lobes. 

 For a time the latter are arranged as two separate lobes, but afterward become 

 consolidated by the capsule and broken up by the invasion of the fibre-muscular 

 septa. 



At birth the prostate measures about 1 2 mm. in its transverse dimension and 

 remains small until puberty, when it begins to rapidly enlarge, acquiring its full pro- 

 portions with the establishment of sexual activity. With the approach of old age, 

 the prostate usually undergoes increase in size, an augmentation often resulting in 

 pathological conditions. 



Variations. Apart from abnormalities in size, the prostate is subject to few variations. 

 Among the latter have been persistence of the original independence of the lateral lobes, ab- 

 sence of the middle and the presence of a fourth lobe. Variations in the relations and mode 

 of ending of the ejaculat< >ry ducts (fusion into a single canal or termination in the prostatic utricle 

 or by a special canal below the crest) or in the prostatic utricle (absence, enlarged size, or un- 

 usual opening) are properly referred to deviations in the development of the generative tract. 



PRACTICAL CONSIDERATIONS : THE PROSTATE GLAND. 



The prostate gland is a portion of the male generative system. The prostatic 

 utricle, or sinus pocularis, is the homologue of the sinus genitalis in the female, the 

 uterine and vaginal cavities, since it represents the persistent part of the fused Miil- 

 lerian ducts (page 2039). Alhough the prostate and the uterus cannot be regarded 

 as homologous organs, they are similar in structure, and would be strikingly alike 

 if the tubular glands found in the inner walls of the uterus were prolonged into its 

 muscular substance. 



During infancy and childhood the prostate is still immature ; at puberty it enlarges 

 coincidently with the enlargement of the testicles. In eunuchs and after castration in 

 man and other animals it is atrophied. The seminal vesicles are in close relation to 

 it and the ejaculatory ducts penetrate it (page 1955). Its size and perfection of struc- 

 ture in animals rise and fall with the breeding season (Hunter, Owen, Griffiths). 

 These facts sufficiently demonstrate the essential relation of the prostate to the gen- 

 erative system. It, however, affords passage to the prostatic urethra, its unstriped 

 muscle-fibres are continuous with the vesical muscle at the trigonum and with the 

 circular fibres of the bladder, and both the anatomical and subjective effects of the 

 more common pathological changes in the prostate are observed in relation to the 

 urinary system, with which, therefore, it is most intimately associated. 



Injuries of the prostate are rare on account of its protected position, and usually 

 involve also the rectum or the bladder. Hemorrhage from the prostato-vesical 

 plexus may be dangerous in amount ; and if a wound extend upward into the neck 

 of the bladder, that organ may become distended with blood and form a tense, globu- 

 lar hypogastric tumor. Infiltration of urine following a prostatic' wound may, in 

 accordance with the situation of the latter, reach the hypogastrium from the pre- 

 vesical space, the ischio-rectal region or the perineum from coincident division of 

 the fascia of Colles, or the recto- vesical space and the pelvis from similar division of 

 the recto-vesical fascia. 



Disease of the prostate, if infectious, is usually gonorrhceal in origin. It is often 

 due to the use of unclean urethral or vesical instruments. It tends to suppuration 

 on account of the very imperfect drainage of the products of inflammation from the 

 numerous follicles. 



