154 ABDOMEN 



ment of both to the sides of the pubic arch. It is closed 

 posteriorly by the fusion of the fascia of Colles with the base 

 of the fasciae of the urogenital diaphragm, but it is open above 

 and in. front, across the front of the symphysis pubis, where 

 its cavity is continuous with the areolar tissue-filled interval 

 between the superficial and the deep fascia of the anterior 

 wall of the abdomen. Within the pouch certain important 

 parts are placed viz., the superficial perineal muscles, the 

 perineal vessels and the scrotal nerves, the long perineal 

 branch of the posterior cutaneous nerve of the thigh, the 

 bulb of the urethra, the crura of the penis, and the termination 

 of the internal pudendal artery. The pouch is partially 

 divided into right and left halves by a median septum, which 

 dips from the fascia of Colles to the inferior surface of the 

 bulb of the urethra. The septum is very perfect posteriorly, 

 but it becomes incomplete towards the scrotum. Anteriorly, 

 the fascia of Colles passes over the scrotum, penis, and 

 spermatic cords, to the anterior aspect of the abdomen, 

 where it becomes continuous with the fascia of Scarpa. 



It follows, from what has already been stated, that if the 

 posterior part of the penile portion of the urethra is in- 

 jured and urine escapes from it, to one or other side of the 

 median plane, it will first distend the corresponding half of 

 the posterior part of the superficial pouch, next, having 

 reached the limit of the septum, it will distend the opposite 

 half. Then because it cannot escape either posteriorly or 

 laterally on account of the attachments of the fasciae, it will 

 push its way forwards and upwards into the areolar tissue 

 between the superficial and deep fascia of the abdominal 

 wall, and it may ascend as far as the thorax unless exit is 

 made for it by free incisions, through the skin and superficial 

 fascia, into the pouch. The extravasated urine which has 

 reached the wall of the abdomen cannot descend into the 

 thighs because of the attachment of Scarpa's fascia to the 

 fascia lata near the inguinal ligaments. 



Dissection. The student can verify the above-mentioned 

 facts in two ways, viz. (i) by inflating the pouch with air, and 

 (2) by dissection. Make a longitudinal incision, large enough to 

 admit the nozzle of the bellows (or, better still, an injection pipe 

 fitted to a bicycle-pump), into the superficial fascia, towards the 

 posterior part of the pouch and a little to one side of the middle 

 line. The cut must be carried through the fascia until the fibres 

 of the superficial perineal muscles are exposed. Introduce the 



