778 



SURGICAL ANATOMY OF THE PERINEUM. 



which separates the back part of the subjacent space into two, being incomplete 

 in front. 



In rupture of the anterior portion of the urethra, accompanied by extravasation 

 of urine, the fluid makes its way forwards, beneath this fascia, into the areolar 



Fig. 390. The Perineum : the Integument and Superficial Layer of 

 Superficial Fascia being reflected. 



tissue of the scrotum, penis, and anterior and lateral portions of the abdomen ; it 

 rarely extends into the areolar tissue on the inner side of the thighs, or backwards 

 around the anus. This limitation of the extravasated fluid to the parts above- 

 named is easy of explanation, when the attachments of the deep layer of the 

 superficial fascia are considered. When this fascia is removed, the muscles con- 

 nected with the penis and urethra will be exposed ; these are, in the middle line, 

 the Accelerator urina3 ; on each side, the Erector penis ; and behind, the Trans- 

 versus perinei. 



The Accelerator urinse is placed in the middle line of the perineum, immediately 

 in front of the anus. It consists of two symmetrical halves, united along the median 

 line by a tendinous raphe. It arises from the central tendon of the perineum, 

 and from the median raphe in front. From this point, its fibres diverge like the 

 plumes of a pen ; the most posterior form a thin layer, which are lost on the 

 anterior surface of the triangular ligament ; the middle fibres encircle the bulb and 

 adjacent part of the corpus spongiosum, and join with the muscle of the opposite 

 side, on the upper part of this body, in a strong aponeurosis ; the anterior fibres, 

 the longest and most distinct, spread out over the sides of the corpus cavernosum, 

 to be inserted partly into this body, anterior to the Erector penis ; partly termi- 

 nating in a tendinous expansion, which covers the dorsal vessels of the penis. 

 The latter fibres are best seen by dividing the muscle longitudinally, and dissecting 

 ?t outwards from the surface of the urethra. % 



Action. This muscle may serve to accelerate the flow of urine or semen 



