308 



ISCIIIATIC ARTERY. 



The ISCHIATIC ARTERY is the larger of the two terminal branches 

 of the anterior division of the internal iliac. It passes downwards 

 between the posterior border of the levator ani, and the pyriformis, 

 resting upon the sacral plexus of nerves and lying behind the internal 

 pudic artery, to the lower border of the great ischiatic notch, where 

 it escapes from the pelvis below the pyriformis muscle. It then 

 descends in the space between the trochanter major and the tube- 

 rosity of the ischium in company with the ischiatic nerves, and 

 divides into branches. 



Fig. 113* 



Its branches within the pelvis are the inferior hasmorrhoidal which 

 supplies the rectum conjointly with the middle hsemorrhoidal and 

 sometimes takes the place of that artery, and the inferior vesical 

 which is distributed to the base and neck of the bladder, the vesicular 

 seminales, and prostate gland. The branches external to the pelvis, 

 are four in number coccygeal, inferior gluteal, comes nervi ischia- 

 tici, and muscular branches. 



The Coccygeal branch pierces the great sacro-ischiatic ligament, 

 and is distributed to the coccygeus and levator ani muscles, and to 

 the integument around the anus and coccyx. 



* The arteries of the perineum ; on the right side the superficial arteries are seen, 

 and on the left the deep. 1. The penis, consisting of corpus spongiosum and corpus 

 cavernosum. The crus penis on the left side is cut through. 2. The acceleratores 

 urinee muscles, enclosing the bulbous portion of the corpus spongiosum. 3. The erector 

 penis, spread out upon the crus penis of the right side. ' 4. The anus, surrounded by 

 the sphincter ani muscle. 5. The ramus of the ischium and os pubis. 6. The tube- 

 rosity of the iscliium. 7. The lesser sacro-ischiatic ligament, attached by its small 

 extremity to the spine of the ischium. 8. The coccyx. 9. The internal pudic artery, 

 crossing the spine of the ischium, and entering the perineum. 10. Inferior hcemor- 

 rhoidal branch. 11. The superncialis perinei artery, giving off a small branch, 

 transvcrsalis perinei, upon the transversus perinei muscle. 12. The same artery on 

 the left side cut off. 13. The artery of the bulb. 14. The two terminal branches of 

 the internal pudic artery; one is seen entering the divided extremity of the crus penis, 

 the artery of the corpus cavernosum ; the other, the dorsalis penis, ascends upon the 

 dorsum of the organ. 



