Common, internal and external iliac arteries

The common iliac artery (a. iliaca communis) is paired and is formed by the division (bifurcation) of the abdominal part of the aorta; its length is 5-7 cm, diameter - 11.0-12.5 mm. The arteries diverge to the sides, go downwards and outwards at an angle, which is greater in women than in men. At the level of the sacroiliac joint, the common iliac artery divides into two large branches - the internal and external iliac arteries.

The internal iliac artery (a.iliaca interna) descends along the medial edge of the large psoas muscle down into the cavity of the small pelvis, and at the upper edge of the large sciatic opening it divides into posterior and anterior branches (trunks), which supply the walls and organs of the small pelvis. The branches of the internal iliac artery are the iliac-lumbar, middle rectal, superior and inferior gluteal, umbilical, inferior vesical, uterine, internal genital and obturator arteries.

The iliac-lumbar, lateral sacral, superior and inferior gluteal and obturator arteries are directed to the walls of the pelvis.

The umbilical, inferior vesical, uterine, middle rectal and internal genital arteries lead to the internal organs located in the pelvic cavity.

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Parietal branches of the internal iliac artery

1. The iliolumbar artery (a. iliolumbalis) runs behind the psoas major muscle, backwards and laterally, and gives off two branches:
   • the lumbar branch (r. lumbalis) goes to the large lumbar muscle and the quadratus lumborum muscle. From it, a thin spinal branch (r. spinalis) goes to the sacral canal;
   • The iliac branch (r. illiacus) supplies blood to the ilium and the muscle of the same name, anastomoses with the deep artery that encircles the ilium (from the external iliac artery).
2. The lateral sacral arteries (aa. sacrales laterales), superior and inferior, are directed to the bones and muscles of the sacral region. Their spinal branches (rr. spinales) pass through the anterior sacral openings to the membranes of the spinal cord.
3. The superior gluteal artery (a. glutealis superior) exits the pelvis through the suprapiriform foramen, where it divides into two branches:
   • the superficial branch (r. superficialis) goes to the gluteal muscles and to the skin of the gluteal region;
   • The deep branch (r. profundus) divides into the upper and lower branches (rr. superior et inferior), which supply the gluteal muscles, mainly the middle and small, and the adjacent pelvic muscles. The lower branch also participates in the blood supply of the hip joint.

The superior gluteal artery anastomoses with branches of the lateral circumflex femoral artery (from the deep femoral artery).

4. The inferior gluteal artery (a. glutealis inferior) is directed together with the internal pudendal artery and the sciatic nerve through the infrapiriform opening to the gluteus maximus muscle, and gives off a thin long artery that accompanies the sciatic nerve (a. comitans nervi ischiadici).
5. The obturator artery (a. obturatoria) together with the nerve of the same name along the lateral wall of the lesser pelvis is directed through the obturator canal to the thigh, where it divides into anterior and posterior branches. The anterior branch (r. anterior) supplies blood to the external obturator and adductor muscles of the thigh, as well as the skin of the external genitalia. The posterior branch (r. posterior) also supplies blood to the external obturator muscle and gives off the acetabular branch (r. acetabularis) to the hip joint. The acetabulum branch not only supplies the walls of the acetabulum, but as part of the ligament of the head of the femur reaches the head of the femur. In the pelvic cavity, the obturator artery gives off a pubic branch (r. pubicus), which at the medial semicircle of the deep ring of the femoral canal anastomoses with the obturator branch from the inferior epigastric artery. If the anastomosis is developed (in 30% of cases), it can be damaged during herniotomy (the so-called corona mortis).

Visceral (visceral) branches of the internal iliac artery

1. The umbilical artery (a. umbilicalis) functions throughout its entire length only in the embryo; it is directed forward and upward, ascending along the back of the anterior abdominal wall (under the peritoneum) to the navel. In an adult, it is preserved as the medial umbilical ligament. From the initial part of the umbilical artery, the following branches off:
   • the superior vesical arteries (aa. vesicales superiores) give off ureteric branches (rr. ureterici) to the lower part of the ureter;
   • artery of the vas deferens (a. ductus deferentis).
2. The inferior vesical artery (a. vesicalis inferior) in men gives off branches to the seminal vesicles and prostate gland, and in women - to the vagina.
3. The uterine artery (a. uterina) descends into the pelvic cavity, crosses the ureter and between the layers of the broad ligament of the uterus reaches the cervix. It gives off vaginal branches (rr. vaginales), a tubal branch (r. tubarius) and an ovarian branch (r. ovaricus), which anastomoses with the branches of the ovarian artery (from the abdominal part of the aorta) in the mesentery of the ovary.
4. The middle rectal artery (a. rectalis media) goes to the lateral wall of the ampulla of the rectum, to the muscle that lifts the anus; gives off branches to the seminal vesicles and prostate gland in men and to the vagina in women. It anatomizes with the branches of the superior and inferior rectal arteries.
5. The internal pudendal artery (a. pudenda interna) leaves the pelvic cavity through the infrapiriform opening, and then through the lesser sciatic opening follows into the ischiorectal fossa, where it is adjacent to the inner surface of the internal obturator muscle. In the ischiorectal fossa it gives off the inferior rectal artery (a. rectalis inferior), and then divides into the perineal artery (a. perinealis) and a number of other vessels. In men, these are the urethral artery (a. urethralis), the artery of the bulb of the penis (a. bulbi penis), the deep and dorsal arteries of the penis (aa. profunda et dorsalis penis). In women - the urethral artery (a. urethralis), the artery of the bulb of the vestibule [of the vagina] (bulbi vestibuli [vaginae]), the deep and dorsal arteries of the clitoris (aa. profunda et dorsalis clitoridis).

The external iliac artery (a. iliaca externa) is a continuation of the common iliac artery. Through the vascular lacuna, it goes to the thigh, where it is called the femoral artery. The following branches depart from the external iliac artery.

1. The inferior epigastric artery (a. epigastrica inferior) ascends along the back of the anterior abdominal wall retroperitoneally to the rectus abdominis muscle. From the initial section of this artery, the pubic branch (r. pubicus) branches off to the pubic bone and its periosteum. From the pubic branch, a thin obturator branch (r. obturatorius) separates, anastomosing with the pubic branch from the obturator artery, and the cremasteric artery (a. cremasterica - in men). The cremasteric artery branches off from the inferior epigastric artery at the deep inguinal ring, supplies blood to the membranes of the spermatic cord and testicle, as well as the muscle that lifts the testicle. In women, this artery is similar to the artery of the round ligament of the uterus (a. lig. teretis uteri), which, as part of this ligament, reaches the skin of the external genitalia.
2. The deep circumflex iliac artery (a. circumflexa iliaca profunda) runs along the iliac crest posteriorly, gives off branches to the abdominal muscles and nearby pelvic muscles; anastomoses with the branches of the iliolumbar artery.