The External Iliac and its Branches.

—The origin of the external iliac ([Fig. 126], k) is described above ([page 307]). It gives off the following branches:

1. A. profunda femoris ([Fig. 126], y).—This is given off just before the external iliac leaves the abdominal cavity. It passes caudad, and about one centimeter from its origin it gives off three branches, sometimes all separately, sometimes two in common. One of these passes mediad in the lateral ligament of the bladder and ramifies on the lateral surface of that organ. A second passes through the abdominal wall and into the fat on the medial surface of the thigh; it sends a branch caudad toward the external genital organs, while its main trunk passes distad in the subcutaneous fat almost to the knee. From one of these two a small branchlet passes in the male to the spermatic cord and accompanies this to the testis; it represents thus the external spermatic artery. The third branch, A. epigastrica inferior, passes directly to the ventral surface of the rectus abdominis muscle, on which it passes craniad, sending branches to the muscles of the abdominal walls. It anastomoses with terminal branches of the internal mammary artery.

The profunda femoris itself passes between the iliopsoas and the pectineus muscles, then to the medial surface of the adductor femoris. It divides into branches which supply the pectineus, adductor longus, adductor femoris, caudofemoralis, quadratus femoris, semimembranosus, and semitendinosus.

[Fig. 127].—Superficial Arteries, Veins, and Nerves on the Medial Side of the Leg.

a, A. and V. femoralis; b, N. femoralis; c, A. profunda femoris; d, A. and V. circumflexa femoris lateralis; e, ramus muscularis; f, A. saphena and V. saphena magna; g, N. saphenus; h, A. and V. articularis genu suprema; i, N. tibialis; j, plantar branch of A. saphena; k, dorsal branch of A. saphena. 1, M. sartorius; 2, M. tensor fasciæ latæ; 3, M. rectus femoris; 4, M. iliopsoas; 5, M. pectineus; 6, M. adductor longus; 7, M. adductor femoris; 8, M. semimembranosus; 9, M. gracilis; 10, M. semitendinosus; 11, medial head of M. gastrocnemius; 12, M. plantaris; 13, M. flexor longus digitorum; 14, M. tibialis anterior; 15, tibia.

2. A. femoralis ([Fig. 127]).—This is the continuation of the external iliac onto the medial surface of the thigh. The artery lies in a triangular depression between the borders of the sartorius (1) and gracilis (9) muscles. The floor of the depression is formed by the adductor longus (6), pectineus (5), vastus internus, and rectus femoris (3) muscles. This triangular depression is known as the iliopectineal fossa, or Scarpa’s triangle; it contains also the femoral vein (a) and saphenous nerve (g), which pass along with the artery. The artery extends distad, and at about the middle of the length of the thigh it passes, along with the vein and nerve, into a groove between the vastus medialis and the adductor femoris. This groove is converted into a canal by the overlying aponeurosis; it is known as Hunter’s canal or the canalis adductorius. At the distal end of the adductor femoris the femoral artery ceases to be superficial and passes between the vastus medialis and the semimembranosus to the popliteal space; it now receives the name A. poplitea.

Branches of the femoral artery:

a. A. circumflexa femoris lateralis ([Fig. 127], d).—The lateral circumflex arises from the femoral about one centimeter from its emergence from the abdominal cavity. It passes craniad and laterad and divides into two main portions. One part passes between the rectus femoris and vastus medialis, gives branches to these muscles, and sends an ascending branch to the structures about the hip-joint, and a descending branch into the vastus medialis muscle. The remainder of the lateral circumflex passes along the inner (lateral) surface of the sartorius (1) to the cranial border of the leg, giving branches to the sartorius (1) and tensor fasciæ latæ (2).