Arteries of the Lower Limb.

The blood-supply of the lower limb is derived from the continuation of the external iliac artery, which, passing under Poupart's ligament, changes its name and becomes the femoral artery, which passes from the lower border of Poupart's ligament to the opening in the insertion of adductor magnus.

The Femoral artery passes through Scarpa's triangle, then enters Hunter's canal.

Scarpa's triangle is a muscular space situated in the upper anterior portion of the thigh : it is triangular with the apex downwards; the base is formed by Poupart's ligament, the outer side by sartorius, the inner side by adductor longus; in the floor are seen ilio-psoas, pectineus and adductor brevis; the contents are femoral artery and vein, anterior crural nerve, and lymph glands.

In Scarpa's triangle it lies on, successively, posterior part of femoral sheath, pubic portion of fascia lata, psoas, pectineus, adductor longus (upper part), and is covered by skin and fascia, superficial glands and vessels. On the outer side of the artery above lies the anterior crural nerve, and lower down the internal saphenous nerve.

The femoral vein lies behind the artery in the lower part of Scarpa's triangle, passes to its inner side above, and is separated from the artery by the outer septum of the femoral sheath.

Hunter's canal is a potential space between the adductor muscles and vastus internus, covered by sartorius; the contents are the femoral artery and vein, and long saphenous nerve.

In Hunter's canal the artery lies on, successively, adductor longus, adductor magnus, and is covered by sartorius, and on the outer side lies vastus interims.

The long saphenous nerve enters the canal with the artery, and crossing over passes out on its inner side.

The femoral vein lies behind the artery on its outer side below and on its inner side above.

Branches (in Scarpa's triangle):

(1) Superficial external pudic,

(2) Superficial epigastric,

(3) Superficial circumflex iliac, all of which supply the lower part of the abdominal wall and superficially the external genital organs.

(4) Muscular,

(5) Deep external pudic,

(6) Profunda, all of which supply the muscles on the front and inner side of the thigh, the profunda sending off a number of perforating branches, which curve backwards and outwards round the femur.

In Hunter's canal (near the lower end) :

(7) Anastomotica magna, which anastomoses with the terminations of the other branches and the articular branches of the popliteal artery.

The femoral artery is continued as the popliteal artery, which lies in the popliteal space at the back of the knee-joint.

The Popliteal Space is a diamond-shaped space at the back of the knee, covered in by a very strong fascia; above, the boundaries are the ham-strings, biceps on the outer side, semi-tendinosus and semimembranosus on the inner side; below, the two heads of the gastrocnemius; the floor is formed by the posterior surface of the femur, and popliteus. The contents are the popliteal artery and vein, the popliteal nerves and lymphatic glands.