i 9 8o HUMAN ANATOMY. 



Prostatitis is attended by (a) much swelling, owing to the vascularity and 

 spongy structure of the gland. As the forward enlargement of the prostate is pre- 

 vented by the resistance of the dense pubo-prostatic ligaments, the subpubic liga- 

 ment, and the firm superior layer of the triangular ligament, the swelling is greatest 

 in the posterior two-thirds of the gland. Its downward extension is evidenced by 

 (6) a sense of weight and uneasiness in the perineum and (c) rectal irritation and 

 tenesmus. Its upward and backward spread is shown by (d ) interference with mic- 

 turition, due to compression of the prostatic urethra and elevation of the vesical out- 

 let. The symptoms of (e) painful and frequent micturition and (/) vesical tenesmus 

 are due in part to the mechanical obstruction, but chiefly to the extension of the 

 inflammation to the trigonal region and to the obstruction by pressure of the pros- 

 tatic venous plexus into which the vesical plexus empties, causing intense conges- 

 tion of the vesical mucosa. The unyielding character of the prostatic sheath produces 

 (g) the heavy, throbbing pain felt in the infrapubic, perineal, and rectal regions, and 

 results in such tension that (h) referred pains are very common, and, on account of 

 the derivation of the nerve-supply of the prostate from the lower three dorsal and 

 upper three sacral segments, are apt to be widely distributed, as, e.g. , pain over the 

 tip of the last rib (tenth dorsal nerve), over the posterior iliac spine (eleventh dorsal 

 nerve), or even in the soles of the feet (third sacral nerve) (Treves); reflex irrita- 

 tion of the inferior hcmorrhoidal nerve may cause intense pruritus ani, sometimes 

 a very annoying symptom. 



Prostatic abscess usually takes the direction of least resistance and opens into 

 the urethra. Its progress towards the pelvis is resisted by the dense investment 

 contributed by the pelvic fascia; towards the perineum, by the superior layer of the 

 triangular ligament. It sometimes points towards the rectum, from which it is sepa- 

 rated by a thinner and less resistant layer of the pelvic fascia, and may then open 

 directly into the rectum, or be guided by it to the perineum. 



Hypertrophy of the prostate to some degree occurs in about one-third of all 

 males who have passed middle life, and in about one-tenth of all males over fifty-five 

 the enlargement becomes of pathological importance. Its cause is unknown. 

 Various theories having a more or less direct bearing upon its anatomical and physio- 

 logical characteristics have been advanced to explain its occurrence, but none has 

 been demonstrated. It has been attributed to (a) the general arterio-sclerosis of old 

 age (Guyon); (b) a primary change in the bladder necessitating a compensatory 

 hypertrophy of the prostate (Harrison); (<:) a growth analogous to uterine fibro- 

 myoma (Thompson); (d) the persistence, in an adjunct sexual organ, of physiological 

 activity intended for the control and determination of the masculine characteristics 

 after the need for such activity had disappeared (White); (e) an attempt to com- 

 pensate quantitatively for a qualitative deterioration in the prostatic secretion, whose 

 function (Fiirbringer) is to facilitate the mobility and vitality of the spermatozoa 

 (Rovsing); and, recently, (/") infection (most often by the gonococcus), aggravating 

 a senile degenerative process (Crandon). 



The enlargement may affect chiefly any of the separate components of the pros- 

 tate, and may thus be adenomatous, myomatous, or fibrous in its character, although 

 usually the glandular element predominates. It may involve particularly the lateral 

 lobes, or may affect almost exclusively the so-called median portion placed at the 

 lower posterior part of the gland, between the ejaculatory ducts. This portion is 

 directly beneath the vesical neck. 



The degree of hypertrophy is extremely variable, the prostate being increased 

 from its normal weight of between four and six drachms to a weight of many ounces, 

 and, of course, correspondingly increased in size. 



It is not possible here to do more than call attention to these varieties of hyper- 

 trophy. Inn its usual and general effects may be considered with reference to their 

 anatomical causation. 



i. The direction of greatest resistance to enlargement is forward (ride supra} 

 and next downward (towards the rectum i. Hence the growth usually takes place 

 in an up\\ard and backward direction, although the resistance offered by the recto- 

 \ epical layer of fascia does n, ,t prevent marked extension in that direction in many 

 cases. As a direct result of this enlargement there follow : (a) compression, flatten- 



