Femoral Arteries

1. Overview

The femoral arteries are the primary arteries responsible for supplying oxygenated blood to the lower limbs. They are major blood vessels that begin at the level of the inguinal ligament and extend down the thigh, providing vital circulation to the muscles, skin, and bones of the lower extremities. The femoral arteries are direct continuations of the external iliac arteries and are crucial for supporting movement and function in the legs. These arteries give rise to several important branches that supply blood to the hip, thigh, and knee regions, as well as the deeper tissues of the leg. The femoral arteries also play an essential role in the circulatory system's overall function by ensuring that the lower body receives adequate oxygen and nutrients for everyday movement and activity.

2. Location

The femoral arteries are located in the upper part of the leg, beginning at the inguinal ligament, where they are a continuation of the external iliac arteries. The arteries travel downward through the femoral triangle, a region in the upper thigh bordered by the inguinal ligament, sartorius muscle, and adductor longus muscle. After passing through the femoral triangle, the femoral arteries enter the deep part of the thigh, where they give rise to various branches. The arteries continue through the thigh and supply blood to the muscles, joints, and skin. At the knee, the femoral arteries transition into the popliteal arteries, which supply blood to the lower leg and foot. The femoral arteries are easily palpated in the groin area, and their pulse can be felt by placing the fingers just below the inguinal ligament.

3. Structure

The femoral arteries are large and muscular arteries that have structural features designed to accommodate the high-pressure blood flow coming from the heart. Some key structural characteristics of the femoral arteries include:

• Origin: The femoral arteries are direct continuations of the external iliac arteries, which arise from the common iliac arteries. They begin at the level of the inguinal ligament and pass through the femoral triangle.

• Course: The femoral arteries travel downward through the anterior and medial aspects of the thigh, where they supply blood to the muscles and tissues of the lower body. As they approach the knee, they transition into the popliteal arteries.

• Diameter and Length: The femoral arteries are relatively large arteries with a diameter of approximately 6 to 8 millimeters in adults, though this can vary. The arteries are typically 10 to 15 centimeters in length, extending from the inguinal ligament to the popliteal fossa (behind the knee).

• Wall Composition: Like all arteries, the femoral arteries consist of three layers:

  • Intima: The innermost endothelial layer that provides a smooth surface for blood flow.

  • Media: The middle layer composed of smooth muscle and elastic fibers that allows the artery to expand and contract with each heartbeat.

  • Adventitia: The outer layer made of connective tissue that provides structural support and anchors the artery to surrounding tissues.

• Branches: The femoral arteries give rise to several important branches as they travel through the thigh. Some key branches include:

  • Deep femoral artery (profunda femoris): Supplies blood to the deep muscles of the thigh, including the quadriceps, hamstrings, and adductors.

  • Superficial epigastric artery: Supplies the abdominal wall and lower portion of the anterior abdominal muscles.

  • Superficial circumflex iliac artery: Supplies the muscles and skin of the inguinal region.

  • External pudendal arteries: Supply blood to the external genitalia.

4. Function

The primary function of the femoral arteries is to supply oxygenated blood to the lower limbs. The femoral arteries serve several important roles in the circulatory system:

• Blood supply to the legs: The femoral arteries are the main suppliers of blood to the muscles, skin, and bones of the thigh, knee, and lower leg. This is crucial for maintaining the normal function and mobility of the lower extremities.

• Support of lower body movement: By supplying blood to the muscles of the legs, the femoral arteries play a critical role in supporting movement and physical activity, such as walking, running, and climbing.

• Delivery of blood to the hip joint: The femoral arteries also supply blood to the hip joint and surrounding structures, ensuring that the joint and muscles in the pelvic region have adequate oxygen and nutrients.

• Supply to the knee joint: The femoral arteries provide blood to the knee joint, where they give off branches to support the surrounding muscles, tendons, and ligaments, promoting healthy joint function.

5. Physiological Role(s)

The femoral arteries play several vital physiological roles that contribute to the proper functioning of the lower extremities and the overall circulatory system:

• Oxygen and nutrient delivery: The femoral arteries ensure that the muscles, bones, and tissues of the lower body receive a continuous supply of oxygenated blood, which is essential for maintaining normal cellular function and metabolic activity. This is particularly important during physical activity when the demand for oxygen increases.

• Support of lower body movement: The femoral arteries supply blood to the muscles of the thigh and lower leg, supporting movements such as walking, running, and jumping. These movements rely heavily on the continuous delivery of oxygenated blood to the muscles of the lower limbs.

• Facilitation of venous return: The femoral arteries help facilitate the return of deoxygenated blood from the legs back to the heart through the venous system. They work in conjunction with the veins of the lower body to maintain efficient circulatory function, reducing the risk of blood pooling or venous stasis.

6. Clinical Significance

The femoral arteries are clinically significant due to their role in supplying oxygenated blood to the lower extremities and pelvis. Several conditions can affect these arteries, leading to serious circulatory problems. Some key clinical conditions associated with the femoral arteries include:

• Peripheral artery disease (PAD): PAD occurs when the arteries, including the femoral arteries, become narrowed or blocked due to atherosclerosis (plaque buildup). This can lead to reduced blood flow to the lower limbs, causing symptoms such as pain, cramping, numbness, and difficulty walking. Treatment options include lifestyle changes, medications, angioplasty, or surgery to restore blood flow.

• Aneurysm of the femoral artery: An aneurysm is a localized dilation or ballooning of the artery. A femoral artery aneurysm can occur due to atherosclerosis, trauma, or genetic factors. If the aneurysm ruptures, it can lead to life-threatening internal bleeding. Treatment typically involves surgical repair or stent placement.

• Femoral artery dissection: A dissection occurs when a tear forms in the inner layer of the femoral artery wall, causing blood to flow between the layers of the vessel. This can lead to reduced blood flow and severe pain, and in some cases, it can result in limb ischemia or stroke. Treatment may involve anticoagulation therapy or surgery to repair the tear.

• Embolism: An embolism is a blockage in the artery caused by a clot or other material traveling from another part of the body. An embolism in the femoral artery can obstruct blood flow to the leg, causing pain, swelling, and tissue damage. Treatment involves anticoagulation therapy and, in some cases, surgical removal of the embolus.

• Trauma to the femoral artery: Trauma or injury to the femoral artery can result in severe bleeding. This is a medical emergency, and immediate surgical intervention is often necessary to control the bleeding and repair the artery.

The femoral arteries are essential for providing blood flow to the lower body, and any dysfunction or blockage in these arteries can lead to serious complications. Early diagnosis, intervention, and preventive measures are crucial for maintaining arterial health and preventing conditions such as PAD, aneurysms, or dissections.