INTERNAL PUDIC. 513 



rosity ; it then ascends forwards and upwards along the ramus of the ischium, 

 pierces the posterior layer of the deep perineal fascia, and runs forwards along 

 the inner margin of the ramus of the pubes ; finally, it perforates the ajiterior 

 layer of the deep perineal fascia, and divides into its two terminal branches, 

 the dorsal artery of the penis, and the artery of the corpus cavernosum. 



Relations. In the first part of its course, within the pelvis, it lies in front of 

 the Pyriformis muscle and sacral plexus of nerves, and on the outer side of the 

 rectum (on the left side). As it crosses the spine of the ischium, it is covered 

 by the Grluteus Maximus, and great sacro-sciatic ligament. In the pelvis, it lies 

 on the outer side of the ischio-rectal fossa, upon the surface of the Obturator 

 Internus muscle, contained in a fibrous canal formed by the obturator fascia 

 and the falciform process of the great sacro-sciatic ligament. It is accompanied 

 by the pudic veins, and the internal pudic nerve. 



Peculiarities. The internal pudic is sometimes smaller than usual, or fails to give off one or 

 two of its usual branches ; in such cases, the deficiency is supplied by branches derived from an 

 additional vessel, the accessory pudic, which generally arises from the pudic artery before its 

 exit from the great sacro-sciatic foramen, and passes forwards near the base of the bladder, on 

 the upper part of the prostate gland, to the perineum, where it gives off the branches, usually 

 derived from the pudic artery. The deficiency most frequently met with, is that in which the 

 internal pudic ends as the artery of the bulb ; the artery of the corpus cavernosum and arteria 

 dorsalis penis being derived from the accessory pudic. Or the pudic may terminate as the 

 superficial perineal, the artery of the bulb being derived, with the other two branches, from the 

 accessory vessel. 



The relation of the accessory pudic to the prostate gland and urethra is of the greatest 

 interest in a surgical point of view, as this vessel is in danger of being wounded in the lateral 

 operation of lithotomy. 



Branches. Within the pelvis, the internal pudic gives off several small branches, 

 which supply the muscles, sacral nerves, and pelvic viscera. In the perineum 

 the following branches are given off: 



Inferior or external hasmorrhoidal. Artery of the bulb. 



Superficial perineal. Artery of the corpus cavernosum. 



Transverse perineal. Dorsal artery of the penis. 



The external hsemorrhoidal are two or three small arteries, which arise from 

 the internal pudic as it passes above the tuberosity of the ischium. Crossing 

 the ischio-rectal fossa, they are distributed to the muscles and integument of 

 the anal region. 



The superficial perineal artery supplies the scrotum, and muscles and integu- 

 ment of the perineum. It arises from the internal pudic, in front of the pre- 

 ceding branches, and piercing the lower border of the deep perineal fascia, runs 

 across the Transversus Perinaei, and through the triangular space between the 

 Accelerator Urinae and Erector Penis, both of which it supplies, and is finally 

 distributed to the skin of the scrotum and dartos. In its passage through the 

 perineum it lies beneath the superficial perineal fascia. 



The transverse perineal is a small branch which arises either from the inter- 

 nal pudic, or from the superficial perineal artery as it crosses the Transversus 

 Perinasi muscle. Piercing the lower border of the deep perineal fascia, it runs 

 transversely inwards along the cutaneous surface of the Transversus Perinaai 

 muscle, which it supplies, as well as the structures between the anus and bulb 

 of the urethra. 



The artery of the hull) is a large but very short vessel, which arises from the 

 internal pudic between the two layers of the deep perineal fascia, and passing 

 nearly transversely inwards, pierces the bulb of the urethra, in which it rami- 

 fies. It gives off a small branch, which descends to supply Cowper's gland. 

 This artery is of considerable importance in a surgical point of view, as it is 

 in danger of being wounded in the lateral operation of lithotomy, an accident 

 usually attended in the adult with alarming hemorrhage. The vessel is some- 

 times very small, occasionally wanting, or even double. It sometimes arises 

 from the internal pudic earlier than usual, and crosses the perineum to reach 

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