384 THE ABDOMEN AND PELVIS 



two fascial layers of the urogenital diaphragm, surrounded by 

 its sphincter muscle (p. 378). 



The bulbo-urethral glands (of Cowper) lie infero-lateral to the 

 membranous urethra, and their ducts pierce the inferior fascia 

 of the diaphragm (p. 378) to open into the cavernous urethra. 

 These glands are sometimes involved in gonorrhceal inflammation 

 of the anterior urethra, and they may give rise to abscesses, 

 which can be recognised on rectal examination. The pus 

 should be evacuated through the perineum. 



The Cavernous (Spongy) Part of the Urethra is about 

 six or seven inches long and is enclosed in the bulb, the corpus 

 cavernosum (spongiosum) urethras and the glans penis. The 

 external orifice on the glans is the narrowest part of the canal, 

 and it may require to be incised to permit the passage of bougies, 

 which will then readily pass along the remainder of the urethra. 

 Enlargement of the external urethral orifice should be carried 

 out by cutting from within outwards towards the fraenulum. 



Immediately within the external orifice, the urethra widens 

 out to form the fossa navicularis, which involves the roof rather 

 than the floor of the canal. Near the posterior end of the fossa 

 a fold of mucous membrane projects downwards from the roof 

 and may temporarily hinder the passage of an instrument, but, 

 by directing the point of the instrument towards the floor of 

 the urethra, this slight obstruction is easily avoided. 



Behind the fossa navicularis, the urethra becomes narrower, 

 but it again enlarges when it reaches the bulb. This is the 

 most dependent part of the fixed urethra, and, on this account, 

 is the commonest site of chronic gonorrhceal inflammation, and, 

 consequently, of organic stricture. 



Stricture may occur at any point in the cavernous urethra. 

 When more than one is present, the first should be dilated to 

 full size before the next is dealt with. If this is not done, it 

 may be impossible to determine whether a bougie is obstructed 

 by a deep stricture or whether its shoulders are caught in the 

 one first encountered. 



In negotiating a difficult stricture in the bulb, great care 

 and gentleness must be exercised lest a false passage be made. 

 The surgeon stands on the left side of the patient and manipulates 

 the handle of the instrument with his right hand. This leaves 

 his left hand free, and the left forefinger, if inserted into the 

 rectum, may be of great assistance in guiding the point of the 

 instrument, thus preventing the formation of a false passage. 



