Male Organs of Generation. 



PROSTATE GLAND. 



THE Prostate Gland (rtpoiur^/u, to .stand before) is a pale, firm, glandular body, 

 which surrounds the neck of the bladder and commencement of the urethra. 

 It is placed in the pelvic cavity, behind and below the symphysis pubis, poste- 

 rior to the deep perineal fascia, and upon the rectum, through which it may 

 be distinctly felt, especially when enlarged. In shape and size it resembles a 

 horse-chestnut. 



Its base is directed backwards towards the neck of the bladder. 



The apex is directed forwards to the deep perineal fascia, which it touches. 



Its under surface is smooth, and rests on the rectum, to which it is connected 

 by dense areolar fibrous tissue. 



Its upper surface is flattened, marked by a slight longitudinal furrow, and 

 placed about three-quarters of an inch below the pubic symphysis. 



It measures about an inch and a half in its transverse diameter at the base, 

 an inch in its antero-posterior diameter, and three-quarters of an inch in depth. 

 Its weight is about six drachms. It is held in its position by the anterior liga- 

 ments of the bladder (pubo-prostatic)] by the posterior layer of the deep perineal 

 fascia, which invests the commencement of the membranous portions of the 

 urethra and prostate gland; and by the anterior portion of the Levator Ani 

 muscle (Levator Prostatce), which passes down on each side from the symphysis 

 pubis and anterior ligament of the bladder to the sides of the prostate. 



The prostate consists of three lobes: two lateral and a middle lobe. 



The two lateral lobes are of equal size, separated behind by a deep notch, and 

 marked by a slight furrow upon their upper and lower surface, which indicates 

 the bi-lobed condition of the organ in some animals. 



The third, or middle lobe, is a small transverse band, occasionally a rounded 

 or triangular prominence, placed between the two lateral lobes, at the under 

 and posterior part of the organ. It lies immediately beneath the neck of the 

 bladder, behind the commencement of the urethra, and above the ejaculatory 

 ducts. Its existence is not constant; but it is -occasionally found at an early 

 period of life, as well as in adults and in old age. In advanced life it often 

 becomes considerably enlarged, and projects into the bladder, so as to impede 

 the passage of the urine. According to Dr. Messer's researches, conducted at 

 Greenwich Hospital, 1 it would seem that this obstruction exists in 20 per cent. 

 of all prostates over sixty years of age. 



The prostate gland is perforated by the urethra and common seminal ducts. 

 The urethra usually lies about one-third nearer its upper than its lower sur- 

 face; occasionally the prostate surrounds only the lower three-fourths of this 

 tube, and more rarely the urethra runs through the lower instead of the upper 

 part of the gland. The ejaculatory ducts pass forwards obliquely through a 

 conical canal, situated in the lower part of the prostate, and open into the pros- 

 tatic portion of the urethra. 



Structure. The prostate is inclosed in a thin but firm fibrous capsule, dis- 

 tinct from thatxlerived from the posterior layer of the deep perineal fascia, and 

 s<>|>;ir:itr<l from it by a plexus of veins. Its .substance is of a pale reddish-gray 

 color, very friable, 'but of great 'density. It consists of glandular substance and 

 muscular tissue. 



1 Mcd.-Chir. Trans., vol. xliii. p. 152. 

 800 



