The internal pudendal artery is a blood vessel of the lower pelvic region which supplies the human genitalia. It arises from the anterior trunk of the internal iliac artery. Then it extends downwards and laterally, leaving the true pelvis through the greater sacrosciatic foramen. Next it arches over the ischial spine and runs medially and forwards.
Following a tortuous course, the internal pudendal artery enters the true pelvis again but through the lesser sciatic foramen, below the pelvic diaphragm. It enters the ischiorectal fossa, running laterally on its wall, reaching the posterior border of the urogenital diaphragm. There, on the inferior pubic ramus, it pierces the urogenital diaphragm from the depth to the surface dividing into six terminal branches:
1) the artery of the bulb of the penis, or the artery of the vestibule in females;
2) the urethral artery, which supplies the membranous urethra;
3) the deep artery of penis, or clitoris (in females);
4) the inferior rectal artery, which supplies the skin and the fatty tissue in the anus and fatty tissue.
5) transverse perineal artery, which supplies the scrotum;
6) scrotal/labial branches.
Below, image and diagram of arteries in the pelvic region. You can see the right common, internal iliac, with its anterior and posterior trunk, and the internal pudendal artery. (Side view)
