External Carotid Artery/Vein

The "external carotid artery" flows upward on the side of the head to branch into various structures in the neck, face, jaw, scalp, and base of the skull. The main vessels that originate from this artery are: (1) the "superior thyroid artery" to the hyoid bone, larynx, and thyroid gland; (2) the "lingual artery" to the tongue, muscles of the tongue, and salivary glands below the tongue; (3) the "facial artery" to the pharynx (throat), palate, chin, lips, and nose; (4) the "occipital artery" to the scalp on the back of the skull and various muscles in the neck; and (5) the "posterior auricular artery" to the ear and scalp over the ear. The external carotid artery terminates by division into the "maxillary" and "superficial temporal arteries."

External Iliac Artery

The abdominal aorta divides to form the "common iliac arteries" in the lower abdomen, and these vessels supply blood to the pelvic organs, gluteral region, and legs. Each common iliac artery descends a short distance and divides into an internal and an external branch. The external iliac artery provides the main blood supply to the legs. It passes down along the brim of the pelvis and divides into two large branches - the "inferior epigastric artery" and a "deep circumflex artery." These vessels supply blood to the muscles and skin in the lower abdominal wall. The external iliac artery passes beneath the inguinal ligament in the lower part of the abdomen and becomes the femoral artery.

External Iliac Vein

The deep veins of the lower leg, such as the "anterior tibial" and "posterior tibial veins," have names that correspond with the artery which they accompany. At the level of the knee, these vessels form a single trunk, the "poplitear vein." This vein continues upward through the thigh as the "femoral vein," which becomes the "external iliac vein" just behind the inguinal ligament in the lowest regions of the abdomen.

Femoral Artery/Vein

The femoral artery, which passes fairly close to the outer surface of the upper thighs, divides into smaller branches to provide blood to muscles and superficial tissues in the thigh. They also supply the skin of the groin and lower abdominal wall. Important branches of the femoral artery include: (1) superficial circumflex iliac artery to the lymph nodes and the skin of the groin; (2) superficial epigastric artery to the skin of the abdominal wall; (3) superficial and deep external pudenal arteries to the skin of the lower abdomen and external genitalia; (4) profunda femoris artery, which is the largest branch of the femoral artery and supplies the hip joint and various muscles in the thigh; and (5) deep genicular artery to the farthest ends of the thigh muscles and to connecting nerve networks around the knee joint. The corresponding femoral vein travels parallel to the artery, carrying the blood from these locations back to the heart.

Saphenous Veins

The superficial veins of the foot and leg interconnect to form a complex network below the skin. These vessels drain into two major trunks: the small and great saphenous veins. The "small saphenous vein" begins on the lateral portion of the foot and passes upward, rising along the back of the calf, enters the popliteal fossa (a depression in the bone behind the knee) to join the popliteal vein. The "great saphenous vein," which is the longest vein in the body, begins on the medial side of the foot. It rises to extend up along the inner side of the leg and penetrates deep into the thigh just below the inguinal ligament in the lower abdomen, where it joins the femoral vein. Near its distant end, it receives vessels that drain the upper thigh, groin, and lower abdominal wall. The femoral and the great saphenous veins merge into the external iliac vein.