220 SURGICAL ANATOMY OP 



minating at the root of the penis and descending at the 

 bulb; and a descending, comprising the membranous and 

 prostatic. Thus the points where the urethra changes di- 

 rection are at the root of the penis and bulb, and it is in 

 this portion of the canal that false passages are most fre- 

 quently made. These curves disappear on catheterism ; 

 the first by merely raising the penis, and the second on the 

 depression of the handle of the instrument between the 

 thighs. So resilient are the urethral walls that a perfectly 

 straight instrument can be readily introduced into the 

 bladder. The urethral canal is distant from the under 

 border of the symphysis about half an inch or a little 

 more, and is consequently about half an inch or a little 

 more below the vesical aperture, which corresponds with 

 the lower border of the symphysis, and is about an inch 

 and a quarter behind it. When not in use the walls of 

 the urethra touch each other, excepting at the orifice of 

 the meatus urinarius and in the bulb, where they are 

 separated by a narrow interspace. 



Catheterism of the Male Urethra. If the urethra be 

 healthy, the sound or catheter will pass by its own 

 weight, and require scarcely any urging. The instrument 

 is to be introduced into the orifice of the urethra, and 

 pressed gently onwards until it has traversed the canal 

 for four or five inches, when the handle is to be brought 

 to the middle line close to the abdomen, in order that 

 the point may traverse the curve below the symphysis ; 

 the handle is then to be brought gently down towards 

 the surgeon, when it should glide into the bladder. 

 The great point is to keep the extremity of the instru- 

 ment traversing the upper wall of the urethra. Besides, 

 being less movable, experience shows that in cases of 

 stricture, the upper wall is less liable to be affected than 



