442 The Perineum 



ischii. Then, passing along the ischial ramus, it enters between the 

 two layers at the base of the triangular ligament, and, ascending 

 almost to the symphysis, runs through the anterior layer of the liga- 

 ment, much diminished in size, as the dorsal artery of the penis. 



Branches. Inferior haemorrhoidal, which are given off as the 

 vessel lies under the obturator fascia : they pass inwards across the 

 ischio-rectal fossa to supply the tissues about the anus, and to ana- 

 stomose with their fellows of the opposite side and with the middle 

 haemorrhoidals (p. 388). They are wounded in lateral lithotomy and 

 also in the division of an anal fistula. The superficial perineal runs 

 in the muscular triangle, and under the deep layer of the superficial 

 fascia, to supply the various tissues of the perineum and scrotum; it 

 may anastomose with a pudic branch of the common femoral. The 

 transverse perineal passes inwards upon the muscle of the same 

 name, and anastomoses with its fellow ; it is apt to be wounded in 

 lateral lithotomy. The artery of the bulb is given off from the 

 main trunk as it ascends between the layers of the triangular 

 ligament ; it is a short thick vessel, and passes inwards to supply the 

 erectile tissue of the bulb and of the corpus spongiosum, giving, in 

 its course, a branch to Cowper's gland, and twigs to the membranous 

 urethra. The artery to the bulb should be well in front of the knife 

 in lateral lithotomy, but if, as sometimes happens, it be given off 

 earlier in the course of the internal pudic it would most likely be 

 severed. Should this accident occur, the bleeding might be controlled 

 by the self-holding forceps, by enlarging the wound and tying, by the 

 petticoated tube, or by compressing the pudic with the finger through 

 the wound against the ischial ramus. 



The artery to the corpus cavernosum comes off, as one of the 

 terminals of the internal pudic, between the layers of the triangular 

 ligament. It is for the crus penis just what the artery to the bulb is 

 for the corpus spongiosum, namely, for the supply of its erectile 

 tissue. It courses in the cavernous body along the side 'of the 

 pectiniform septum. 



The dorsal artery of the penis is the other terminal branch, 

 and, passing through the anterior layer of the triangular ligament, 

 and through the suspensory ligament of the penis, it courses by the 

 side of the vein, giving off branches to the corpus cavernosum, and 

 ending in the glans, where it anastomoses with its fellow. It supplies 

 the skin of the penis, even to the prepuce. Though there are two dorsal 

 arteries of the penis, there is but one dorsal vein. 



Sometimes the pudic is not large enough to give off all these 

 branches ; ending as the artery to the bulb, its terminal branches are 

 then derived from an accessory internal pudic, which is either given 

 off from the internal pudic itself, before it passes out of the great 

 sacro-sciatic foramen, or else from the anterior division of the internal 

 iliac. This irregular vessel hurries along the floor of the pelvis 



