942 THE VASCULAR SYSTEM. 



urethrse, and then, turning forwards a short distance from the side of the urethra, i1 

 pierces the inferior fascia of the urogenital diaphragm and enters the substance of the 

 bulb. It passes onwards in the corpus cavernosuin urethrse to the glans, where il 

 anastomoses with its fellow and with the dorsal arteries of the penis. 



It supplies the sphincter of the membranous urethrse, bulbo-urethral gland (Cowper) 

 the corpus cavernosum urethrse, and the penile part of the urethra. In the female thi; 

 artery supplies the bulb of the vestibule. 



(g) The profunda artery of the penis (O.T. artery of the corpus cavernosum) in thq 

 male, and of the clitoris in the female, is usually the larger of . the two termina 

 branches. Immediately after its origin it enters the crus penis, and runs forwards li- 

 the corpus cavernosum penis, which it supplies. 



(h) The dorsal artery of the penis in the male, and of the clitoris in the female ; 

 passes forwards between the layers of the suspensory ligament, and runs along th< 

 dorsal surface of the penis, with the dorsal nerve immediately to its lateral side, whilst i ; 

 is separated from its fellow of the opposite side by the deep dorsal vein, which lie 

 in the median plane. It supplies the superficial tissues on the dorsal aspect of th 

 penis, sends branches into the corpus cavernosum penis to anastomose with the profund; 

 artery of the penis, and its terminal branches enter the glans penis, where they anastc 

 mose with the arteries to the bulb. It anastomoses also with the external pudenda, 

 branches of the femoral. 



3. Arteria Glutaeal Inferior. The inferior gluteal artery (O.T. sciatic), (Figs. 77' i 

 and 776) arises from the hypogastric artery, either separately or by a commo] 

 trunk with the internal pudendal artery. It descends a little postero-latera 

 to the internal pudendal vessels, pierces the pelvic fascia, runs backwards betwee: ' 

 the first and second, or second and third sacral nerves, and, passing between th ; 

 piriformis and coccygeus muscles, leaves the pelvis through the lower part of th 

 greater sciatic foramen, and enters the buttock just below the piriformis. In th 

 buttock it descends posterior and to the medial side of the sciatic nerve deep t| 

 the glutseus maximus, and posterior to the obturator internus, the two gemell 

 the quadratus femoris, and upper part of the adductor magnus muscles, to th.; 

 proximal part of the thigh. 



Below the lower border of the glutseus maximus the artery is comparative! 

 superficial, and having given off its largest branches, it runs distally, as a lonj 

 slender vessel, with the posterior femoral cutaneous nerve. 



Branches In the pelvis. Small and irregular branches supply the adjacent visce; 

 and muscles and the sacral nerves ; they anastomose with branches of the intern 

 pudendal and lateral sacral arteries. 



In the buttock. (a) Muscular branches are given off to the muscles of the buttoc 

 and to the proximal parts of the hamstring muscles. They anastomose with the intern 

 pudendal, medial circumflex, and obturator arteries. (&) The coccygeal branch aris 

 immediately after the artery leaves the pelvis. It runs medially, pierces the sacro-tuberoi 

 ligament and the glutseus maximus, and ends in the soft tissues over the posterior aspe 

 of the lower part of the sacrum and of the coccyx. It gives several branches to tl ; 

 glutaeus maximus, and anastomoses with branches of the glutseal and lateral sacr; 

 arteries, (c) An anastomotic branch passes laterally, superficial or deep to the sciat 

 nerve, towards the greater trochanter of the femur. It anastomoses with branches 

 the gluteal, internal pudendal, medial and lateral circumflex, and the first perforatii 

 arteries, taking part in the formation of the so-called "crucial anastomosis." (d) Cutaneo 

 branches, accompanying twigs of the posterior cutaneous nerve of the thigh, pass roui 

 the lower border of the gluteeus maximus muscle to the integument, (e) The a. comita 

 n. ischiadici is a long slender branch which runs distally on the surface, or in the substan 

 of the sciatic nerve. It supplies the nerve, and anastomoses with the perforating arteri 

 and with the termination of the profunda femoris artery. 



AETEEIES OF THE INFEEIOK EXTKEMITY. 



The main artery of each lower limb is continued from the corresponding coi 

 mon iliac artery. It descends as a single trunk as far as the lower border of t 

 popliteus, and ends there by dividing into the anterior and posterior tibial arteri 

 Distinctive names are, however, applied to different parts of the artery, correspon 

 ing to the several regions through which it passes. Thus in the abdomen it 



