Arteries are muscular tubes that transport oxygen-rich blood away from the heart to nourish the body’s tissues and organs. The leg’s circulatory system is a complex network designed to deliver the high volume of blood needed by the large muscles responsible for mobility and standing. This system originates from the body’s main arterial supply, ensuring the entire lower limb receives necessary nutrients and oxygen.
The Primary Conduit: The Femoral Artery
The main artery supplying the leg is the Femoral Artery, a direct continuation of a major vessel from the pelvis. This vessel begins where the External Iliac Artery crosses underneath the inguinal ligament, a strong band of tissue near the groin. The Femoral Artery is one of the body’s largest arteries, reflecting its significant role in supplying the entire lower limb.
Shortly after its beginning, it gives rise to the Deep Femoral Artery, which plunges deep into the thigh muscles. This deep branch provides blood to the large muscle masses of the thigh and the head of the femur. The main trunk of the Femoral Artery continues its course down the leg.
The Arterial Pathway Through the Thigh
The Femoral Artery begins in the femoral triangle, a distinct triangular area in the upper thigh located just below the groin crease. In this initial segment, the artery is relatively close to the skin’s surface. The artery is contained within a protective sheath of connective tissue, alongside its corresponding vein.
After passing through the femoral triangle, the artery moves into the adductor canal (or Hunter’s canal), which guides the vessel down the middle third of the thigh. This muscular tunnel moves the artery from the front of the thigh toward the back of the knee. The artery exits this canal through the adductor hiatus, a gap in the adductor magnus muscle, marking the end of its course through the thigh.
Blood Supply to the Lower Leg and Foot
Once the Femoral Artery passes through the adductor hiatus and enters the space behind the knee, it changes its name to the Popliteal Artery. The Popliteal Artery is situated deep within the popliteal fossa, the area at the back of the knee joint. It supplies blood to the knee joint and the large muscles of the calf.
The Popliteal Artery continues its descent until it reaches the lower border of the popliteus muscle, where it immediately divides into its major terminal branches. The first branch is the Anterior Tibial Artery, which passes forward between the tibia and fibula to supply the muscles in the front of the leg. The remaining trunk divides to form the Posterior Tibial Artery and the Fibular Artery.
The Posterior Tibial Artery runs down the back of the leg, supplying the deep calf muscles. It continues toward the ankle, passing just behind the inner ankle bone, where it finally branches into the arteries that supply the sole of the foot. Meanwhile, the Anterior Tibial Artery crosses the front of the ankle joint and becomes the Dorsalis Pedis Artery, the main vessel supplying the top of the foot.
Locating the Pulse
The anatomical path of these vessels allows medical professionals to assess circulation by checking for a pulse at specific points. The Femoral Pulse is the strongest and most reliably accessible pulse in the leg, found high in the groin crease, midway between the hip bone and the pubic bone.
The Dorsalis Pedis Pulse is another commonly checked point, located on the top of the foot, slightly to the side of the large tendon that moves the big toe. The Posterior Tibial Pulse can also be felt just behind and slightly below the prominent inner ankle bone. Checking these distal pulses confirms blood flow through the arterial network all the way to the foot.