internal external iliac artery

3 min read 14-03-2025

The iliac arteries are major blood vessels that supply blood to the lower limbs and pelvic organs. Understanding their anatomy and function is crucial for medical professionals and anyone interested in human anatomy. This article will delve into the internal and external iliac arteries, exploring their origins, branches, and clinical significance.

Origin and Anatomy

Both the internal and external iliac arteries arise from the common iliac artery, a major vessel formed by the bifurcation of the abdominal aorta at the level of the fourth lumbar vertebra. This bifurcation typically occurs around the level of the sacroiliac joint.

External Iliac Artery

The external iliac artery is the larger of the two and primarily supplies blood to the lower limb. It runs along the medial border of the psoas major muscle, passing deep to the inguinal ligament. Once it crosses the inguinal ligament, it changes its name to the femoral artery, continuing its journey down the leg.

Key Branches:

Inferior epigastric artery: Supplies blood to the lower abdominal wall.
Deep circumflex iliac artery: Supplies blood to the abdominal wall and gluteal region.

Internal Iliac Artery (Hypogastric Artery)

The internal iliac artery, also known as the hypogastric artery, primarily supplies blood to the pelvic organs and gluteal region. It is shorter and smaller than the external iliac artery. It branches extensively within the pelvis.

Key Branches: (Note: Numerous variations exist; these are some of the major ones)

Anterior Division: Supplies the bladder, rectum, uterus (in females), and other pelvic viscera. Key branches include:
- Umbilical artery: In adults, the majority of this artery is obliterated, remaining as the medial umbilical ligament.
- Superior vesical artery: Supplies the superior portion of the urinary bladder.
- Inferior vesical artery (in males): Supplies the inferior portion of the urinary bladder and prostate. In females, this is often replaced by the vaginal artery.
- Middle rectal artery: Supplies the rectum.
- Uterine artery (in females): Supplies the uterus and vagina.
- Vaginal artery (in females): Supplies the vagina.
- Obturator artery: Supplies the medial thigh muscles.
- Internal pudendal artery: Supplies the external genitalia and perineum.
Posterior Division: Primarily supplies the gluteal muscles and other structures in the buttock. Key branches include:
- Iliolumbar artery: Supplies the iliacus and quadratus lumborum muscles.
- Lateral sacral arteries: Supplies the sacrum and surrounding structures.
- Superior gluteal artery: Supplies the gluteal muscles.
- Inferior gluteal artery: Supplies the gluteal muscles.

Clinical Significance

Understanding the iliac arteries is crucial in several clinical scenarios:

Atherosclerosis: The iliac arteries are susceptible to atherosclerosis, leading to stenosis (narrowing) or occlusion (blockage). This can cause claudication (pain in the legs during exercise) or even limb ischemia (reduced blood supply). Angiography and interventions like angioplasty or stenting may be necessary.
Trauma: Injuries to the iliac arteries can result from penetrating or blunt trauma, leading to significant hemorrhage. Rapid intervention is critical in such cases.
Pelvic Surgery: Surgeons must be meticulous during pelvic surgeries to avoid damaging the internal iliac artery and its branches.
Embolization: In cases of uncontrolled bleeding, embolization (blocking of the artery) might be used to stop hemorrhage.
Aneurysms: While less common, aneurysms (bulges in the artery wall) can occur in the iliac arteries and require careful monitoring and treatment.

How are Internal and External Iliac Arteries Distinguished?

Distinguishing between the internal and external iliac arteries involves anatomical location and branching patterns. The external iliac artery continues as the femoral artery, passing under the inguinal ligament. The internal iliac artery, much shorter, branches extensively within the pelvis to supply pelvic organs and the gluteal region.

Conclusion

The internal and external iliac arteries are vital vessels supplying blood to the lower extremities and pelvic viscera. Their intricate anatomy and potential for clinical complications necessitate a thorough understanding for healthcare professionals. This knowledge is critical for diagnosis, treatment, and the prevention of vascular diseases affecting these essential arteries. Further study of specific branch arteries and their individual clinical implications is highly recommended for a more in-depth understanding.