434 ABDOMEN 



The orifice is a vertical slit, and its lower end is connected 

 with the prepuce by a fold of skin, termed the fremdum 

 pr&putii. 



In the bulb and in the glans penis the erectile tissue of 

 the corpus cavernosum urethrae is disposed very unequally 

 around the urethra. In the bulb it is massed chiefly below 

 or behind the tube, whilst in the glans it is placed chiefly in 

 front and on each side, a very thin layer lying posteriorly. 



The ducts of the bulbo-urethral glands (O.T. Cowper's) 

 pierce the floor and open into the cavernous part of the urethra 

 about 25 mm. (one inch) in front of the inferior fascia of the 

 urogenital diaphragm (Figs. 202, 203). The orifices are 

 minute and difficult to find, but by making a small hole in the 

 wall of the duct, as it emerges from the gland, and passing a 

 fine bristle along it, the dissector may be able to find the 

 opening in the urethral floor. After piercing the inferior 

 fascia of the urogenital diaphragm the ducts proceed forwards, 

 first in the erectile tissue, and then in the submucous layer, 

 towards their terminations. 



The walls of the urethra are always in apposition except 

 when urine is flowing through it, and a transverse section 

 through the spongy portion, except at its anterior part, has the 

 appearance of a transverse slit. In the fossa navicularis, how- 

 ever, the slit becomes vertical, showing that there the side 

 walls are in contact. 



Mucous Membrane of the Urethra. The mucous lining 

 of the urethra is continuous posteriorly with that of the 

 bladder, and anteriorly with the integument of the glans 

 penis. It is continuous also with the mucous membrane of the 

 various ducts which open into the urethra. Scattered over 

 its whole surface are the mouths of numerous minute recesses, 

 called lacuna, urethraks. As a general rule, their openings 

 are directed forwards, and they are largest on the dorsal wall, 

 where some are large enough to catch the point of a small 

 catheter or bougie, especially the lacuna magna, which is 

 situated in the posterior part of the glans penis. 



Direction of the Urethral Canal. The prostatic portion 

 is directed downwards and very slightly forwards. The 

 membranous part describes a gentle curve behind the sym- 

 physis. The concavity of the curve looks forwards and 

 upwards. The cavernous part first ascends, and then curves 

 downwards, The urethra, therefore, in the flaccid condition 



