The iliac artery is a major blood vessel in the human circulatory system, delivering oxygenated blood throughout the body. Understanding its location and network is fundamental to comprehending its function. These arteries are essential components of the vascular system that ensures all tissues receive the necessary supply for their proper operation.
Anatomical Position
The iliac arteries originate from the abdominal aorta, the body’s largest artery. The abdominal aorta branches into two common iliac arteries at the fourth lumbar vertebra. There is one common iliac artery on the right side of the body and one on the left.
Each common iliac artery extends downwards and slightly outwards, traveling along the inner border of the psoas major muscle. The right common iliac artery is about 1 centimeter longer than its left counterpart. These arteries are 4 centimeters long in adults and measure more than a centimeter in diameter.
They continue this path until they reach the front of the sacroiliac joint, where the spine connects to the pelvis. Their terminal bifurcation is crossed anteriorly by the ureters. The common iliac arteries are accompanied by the common iliac veins, which lie directly behind them.
Primary Divisions
Each common iliac artery divides into two main branches: the external iliac artery and the internal iliac artery. These divisions occur at the pelvic brim. The external iliac artery is the larger of these two branches and serves as the primary conduit for blood flow to the lower extremities.
The external iliac artery continues its course downward, extending along the medial border of the psoas major muscle. It then passes beneath the inguinal ligament. Once it crosses this ligament, its name changes, and it becomes the femoral artery. This artery then extends into the leg, providing blood flow to the legs and feet. The external iliac artery also gives rise to smaller branches that supply parts of the lower abdominal wall.
In contrast, the internal iliac artery descends into the pelvis. This artery is shorter and smaller than the external iliac artery, measuring about 3 to 4 centimeters in length. It supplies blood to the organs and structures within the pelvic region. This includes the walls and viscera of the pelvis, the gluteal region, and reproductive organs.
Circulatory Function
The iliac arteries are integral components of the body’s circulatory system, with their primary function being the consistent delivery of oxygenated blood and nutrients. They transport this enriched blood from the aorta to the extensive network of vessels supplying the lower limbs, various pelvic organs, and reproductive organs. This continuous and robust blood supply is necessary for the proper functioning, metabolic activity, and overall health of these body parts.
For the lower extremities, the external iliac artery and its continuation as the femoral artery ensure that muscles, bones, and other tissues receive the oxygen and glucose required for movement, growth, and cellular viability. Without adequate blood flow, these areas can experience discomfort, pain, and impaired function. Similarly, the internal iliac artery provides essential nourishment to organs like the bladder, parts of the intestines, and the reproductive organs, supporting their specialized activities and maintaining their structural integrity. This consistent delivery of blood is fundamental for maintaining cellular health and efficiently removing metabolic waste products, which are then carried away by the venous system. The efficient operation of these arteries underscores their importance in sustaining the vitality of the lower body.
Common Medical Concerns
The iliac arteries can be affected by several medical conditions that significantly impair blood flow, leading to various health issues. One prevalent condition is atherosclerosis, where fatty and cholesterol deposits, known as plaque, gradually accumulate inside the artery walls. This progressive buildup narrows the arteries, impeding the smooth flow of blood and potentially leading to partial or complete blockages.
Atherosclerosis in the iliac arteries is a common form of peripheral artery disease (PAD), which often manifests as discomfort, cramping, or pain in the buttocks, hips, or thighs during physical activity. This symptom, medically termed claudication, arises because the affected muscles do not receive sufficient oxygen-rich blood to meet their increased demand. If the condition progresses without intervention, it can lead to pain even at rest, the development of non-healing ulcers, and in severe instances, critical limb ischemia and tissue loss.
Another concern is an iliac artery aneurysm, which involves a localized bulging and weakening in a segment of the artery wall. These aneurysms can develop due to underlying factors such as advanced atherosclerosis, certain infections, or trauma. While often remaining asymptomatic for extended periods, a large iliac aneurysm carries a substantial risk of rupture, which is a medical emergency that can cause life-threatening internal bleeding. Conditions affecting the iliac arteries can profoundly impair blood flow to both the legs and the sensitive pelvic organs, necessitating medical attention.