Blood Supply of the Lower Limb

The main arteries of the lower limbs can be summarized as:

  1. Femoral artery

    • This artery is the continuation of the iliac artery and it passes through the femoral triangle and adductor canal, passing through the adductor hiatus to enter the popliteal fossa. It also gives off the following branches:

      • Lateral circumflex femoral

      • Medial circumflex femoral

      • Four perforating arteries

      • Muscular branches to extensor and adductor muscles

  2. Popliteal artery

    • This artery is the continuation of the femoral artery at the adductor hiatus and it travels through the popliteal fossa. It also gives off the following branches:

      • Five genicular arteries that anastomose to ensure continued blood flow if the popliteal artery is kinked (during flexion).

  3. Posterior tibial artery

    • This artery is the continuation of the popliteal artery inferior to the lower border of the popliteus. It also gives off the following branch:

      • Fibular artery

  4. Anterior tibial artery

    • This artery is the continuation of the popliteal artery in the popliteal fossa.

  5. Dorsalis pedis artery

    • This artery is the continuation of the anterior tibial artery. It also gives off the following branches:

      • Branches to tarsal bones

      • First dorsal metatarsal artery

Clinical Notes:

  1. The femoral pulse can be palpated at the femoral triangle just below the midpoint of the inguinal ligament. The femoral artery can use utilized to collect blood samples or insert catheters.

  2. The dorsalis pedis pulse can be palpated in front of the ankle between the extensor hallucis longus and extensor digitorum longus tendons.

Venous Drainage

The venous drainage of the lower limbs can be summarized as:

  1. Great saphenous vein

    • This vein receives tributaries from the union of the dorsal vein of the big toe and dorsal venous arch of the foot

    • This vein continues as the femoral vein

  2. Small saphenous vein

    • This vein receives tributaries from the dorsal vein of the little toe with dorsal venous arch

    • This vein continues as the popliteal vein

Clinical Notes:

  1. Varicose veins occurs as a result of incompetent veins that have dilated to the point that their valve cusps are no longer able to close. This allows blood to flow inferiorly or remain stagnant. This may occur due to long stretches of standing or increased abdominal pressure obstructing the vena cava in pregnant women.

  2. Deep vein thrombosis occurs as a result of the formation of a blood blot in deep veins that can break free and travel towards the heart causing a pulmonary thromboembolism or travel towards the lungs causing obstruction of a pulmonary artery. This may occur due to muscular inactivity during long flights or incompetent fascia that fails to resist muscle expansion, thereby reducing the effectiveness of the musculovenous pump.