I930 HUMAN ANATOMY. 



prediaphragmatic portion) and membranous urethrae ; the /r£».f/a/zV urethra, of course, 

 extends thence to the bladder. All of these terms are in constant use, and a consid- 

 eration of the urethra from the stand-points suggested by its subdivisions as above 

 described cannot fail to be useful in relation to its injuries and diseases. 



Subcutaneous rtipture of the urethra is rarely seen in its penile portion. In the 

 great majority of cases (92 per cent.) it affects the perineal portion (80 per cent, from 

 falls astride, 12 per cent, from perineal blows), and in the majority of these the bul- 

 bous urethra suffers most severely. The mechanism of rupture varies with the size 

 and shape of the vulnerating body, but the urethra is usually crushed against either 

 the transverse ligament or subpubic arch, the anterior face of the pubis (which is 

 placed at an angle of only 30 degrees with the horizon), or the ischiatic or pubic 

 rami. In cases of fracture of the pelvis or temporary or permanent disjunction of the 

 pubic symphysis, the membranous urethra may be lacerated by the fragments or may 

 be torn partly or completely across by the drag upon it of the triangular ligament. 



The rupture may be complete or incomplete, the former being more common in 

 the membranous urethra on account of {a) its fixity ; (<^) the density of the triangular 

 ligament ; (r) its proximity to the pubes and ischium ; (^) the relative thinness of its 

 walls ; and (^) the absence of the protection afforded by erectile tissue, which is 

 present in only a scanty layer. The symptoms are hemorrhage from the meatus or 

 into the bladder, or both ; difficult or painful urination, or retention of urine ; swelling 

 usually in the perineum or at the perineo-scrotal junction ; and later extravasation of 

 urine, which will be guided in certain definite directions in accordance with the locality 

 of the rupture {vide infra). 



Urethritis, almost always due to gonococcus infection, but sometimes caused by 

 the ordinary pyogenic organisms aided by congestion from trauma (catheter urethritis), 

 may from the anatomical stand-point best be divided into anterior and posterior. 



Anterior 2irethritis affects that portion of the urethra in front of the compressor 

 urethrae muscle ; the following characteristic symptoms and complications are due to 

 its situation : (^) free discharge from the meatus ; (<^) ardor urince, due partly to 

 the mechanical disturbance of the flow of the stream of urine (converting the urethral 

 slit into a suitable channel and separating the apposed walls), but chiefly to the con- 

 tact of the acid and saline urine with the inflamed mucosa ; {c) freque7it and painful 

 erection, due (i) to irritation of the lumbar centre, causing increased blood-supply 

 through the dorsal arteries and the arteries to the bulb and corpora cavernosa ; (2) 

 to the compression of the dorsal vem of the penis by clonic contraction of the com- 

 pressor urethrae and bulbo-cavernosus muscles, and to the compression of the penis 

 itself against the pubic arch by similar contraction of the ischio-cavernosus also 

 obstructing the return current ; (3) to the loss of elasticity by the congested, infil- 

 trated mucous membrane and submucous connective tissue, which are not able to 

 stretch as they normally do when the cavernous bodies become engorged with blood ; 

 (flf) chordee, a curvation of the penis due to the fact that the inflammation extends to the 

 submucous connective tissue, and thence to the trabeculae of the erectile tissue of the 

 spongy body. The exudation of lymph consequent upon this fills up the intertra- 

 becular spaces, which by engorgement furnish the ordinary mechanical element 

 of normal erection. When the organ becomes erect the corpora cavernosa are fully 

 engorged with venous blood. The infiltrated portion of the corpus spongiosum, how- 

 ever, remains rigid and undilatable, the blood being unable to find its way into the 

 partially obliterated spaces. If the inflammation extends to the corpora cavernosa, 

 erections will be equally painful ; but in this case the curve will be upward. If only 

 one cavernous body is involved, the curve, of course, will be towards the affected 

 side ; {e) follicular ox peri-tirethral abscess, due to involvement of the urethral folli- 

 cles and to occlusion of their mouths by swelling of the mucosa, preventing drainage 

 into the urethra ; (/") lyniphajigitis and bubo, usually associated with retention of 

 discharge and inflammation between the prepuce and glans, the infection extending 

 by the superficial lymphatics and reaching one of the superficial nodes lying just below 

 Poupart's ligament, embedded in the subcutaneous cellular tissue and above the fascia 

 lata. The lymphatics more directly connected with the urethra itself belong to the 

 deeper set, and run beneath the pubic arch to join the deep pelvic lymphatics and to 

 terminate in the lumbar nodes. 



