and passes upwards and medially, between the superficial and deep layers of the superficial fascia of the abdominal wall, towards the umbilicus. It supplies the sub-inguinal glands and the integument, and anastomoses with its fellow of the opposite side, with the inferior epigastric, and with the superficial circumflex iliac and superficial external pudendal arteries. (c) Arteria Pudenda Externa Superficialis.-The superficial external pudendal artery also springs from the front of the femoral artery, and, after piercing the femoral sheath and the fascia cribrosa, runs upwards and medially towards the pubic tubercle, where it crosses superficial to the spermatic cord and divides into terminal anterior scrotal or labial branches according to the sex. It supplies the integument of the lower part of the abdominal wall, the root of the dorsum of the penis in the male, and the region of the mons Veneris in the female, and it anastomoses with its fellow of the opposite side, with the deep external pudendal, with the dorsal artery of the penis, and with the superficial epigastric artery. (2) Rami Musculares. The muscular branches are distributed to the pectineus and the adductor muscles on the medial side, and to the sartorius and the vastus medialis on the lateral side. (3) Arteria Pudenda Externa Profunda.-The deep external pudendal artery arises from the medial side of the femoral. It runs medially, anterior to the pectineus, and either anterior or posterior to the adductor longus, to the medial side of the thigh; it then pierces the deep fascia, and terminates in the scrotum, where it anastomoses with the posterior scrotal branches of the perineal and the anterior scrotal branches of the superficial external pudendal arteries, and with the external spermatic branch of the inferior epigastric artery. In the female it terminates in the labium majus. (4) Arteria Profunda Femoris.-The profunda artery (Fig. 778) is the largest branch of the femoral artery. It arises about 37 mm. (an inch and a half) distal to the inguinal ligament, from the lateral side of the femoral artery. It curves backwards and medially, passes posterior to the femoral artery, and runs distally, close to the medial aspect of the femur, to the distal third of the thigh, where it perforates the adductor magnus and passes to the back of the thigh. Its termination is known as the fourth perforating artery. As the profunda descends it lies anterior to the iliacus, the pectineus, the adductor brevis, and the adductor magnus. It is separated from the femoral artery by its own vein, by the femoral vein, and by the adductor longus muscle. Branches. (a) Muscular branches are given off from the profunda, both in the femoral trigone and whilst it lies between the adductor muscles; many of them terminate in the adductors, others pass through the adductor magnus, and terminate in the hamstrings, where they anastomose with the transverse branch of the medial circumflex and with the proximal muscular branches of the popliteal artery. (b) The lateral circumflex artery (Figs. 778 and 779) springs from the lateral side of the profunda, or occasionally from the femoral artery proximal to the origin of the profunda. It runs laterally, anterior to the iliacus and between the superficial and deep branches of the femoral nerve, to the lateral border of the femoral trigone; then, passing posterior to the sartorius and the rectus femoris, it terminates by dividing into three terminal branches -the ascending, the transverse, and the descending. Before its termination it supplies branches to the muscles mentioned and to the proximal part of the vastus intermedius. (i.) The ascending terminal branch runs proximally and laterally, posterior to the rectus femoris and the tensor fascia latæ, along the linea intertrochanterica, to the anterior borders of the glutæi, medius and minimus, between which it passes to anastomose with the deep branches of the superior gluteal artery. It supplies twigs to the neighbouring muscles, anastomoses with the gluteal, the deep circumflex iliac, and the transverse branch of the lateral circumflex arteries, and, as it ascends along the linea intertrochanterica, it gives off a branch which passes, between the two limbs of the ilio-femoral ligament, into the hip-joint. (i.) The transverse terminal branch is small; it runs laterally, between the vastus intermedius and the rectus femoris, passes into the substance of the vastus lateralis, winds round the femur, and anastomoses with the ascending and descending branches, with the perforating branches of the profunda, and with the inferior gluteal and medial circumflex arteries. (iii.) The descending terminal branch runs distally, posterior to the rectus and along the anterior border of the vastus lateralis, accompanied by the nerve to the latter muscle. It anastomoses with the transverse branch, with twigs of the inferior perforating arteries, with the arteria genu suprema of the femoral, and with the superior lateral genicular branch of the popliteal artery. (c) The medial circumflex artery springs from the medial and posterior part of the profunda, at the same level as the lateral circumflex, and runs backwards, through the floor of the femoral trigone, passing between the psoas major and the pectineus; then it crosses the upper border of the adductor brevis, and continuing backwards, below the neck of the femur, it passes between the adjacent borders of the obturator externus and the adductor brevis to the upper border of the adductor magnus, where it divides into two terminal branches, a transverse and a profunda branch (O.T. ascending). Branches. (i.) An acetabular branch is given off as the artery passes below the neck of the femur. It ascends to the acetabular notch where it anastomoses with twigs from the posterior branch of the obturator artery, and it sends branches into the acetabular fossa and along the ligamentum teres to the head of the femur. (ii.) A superficial branch, which passes medially, anterior to the pectineus and between the adductors brevis and longus. (iii) Muscular branches are given off to the neighbouring muscles. The largest of these branches usually arises immediately before the termination of the artery; it runs distally, on the anterior aspect of the adductor magnus, and anastomoses with the muscular branches of the profunda artery. (iv.) The profunda terminal branch (ascending) passes upwards and laterally, between the obturator externus and the quadratus femoris to the trochanteric fossa of the femur, where it anastomoses with branches of the superior and inferior gluteal arteries. (v.) The transverse terminal branch runs backwards to the hamstring muscles, usually between the lower border of the quadratus femoris and the upper border of the adductor magnus, but it may pierce the upper part of the adductor magnus. It anastomoses, in front of the distal part of the gluteus maximus, with the inferior glutaæal and first perforating arteries and with the transverse branch of the lateral circumflex, and, in the substance of the hamstrings, with the muscular branches of the profunda. (d) The perforating arteries (Fig. 780), including the terminal branch of the profunda, are four in number. They curve posterolaterally, round the posterior aspect of the femur, lying close to the bone and anterior to the wellmarked tendinous arches which interrupt the continuity of muscular attachments; their ter minal branches enter Obturator internus the vastus lateralis and anastomose, in its substance, with the one another, with descending branch of the lateral circumflex, with the arteria genu sup rema, and with the superior lateral genicular branch of the popliteal. The first perforating artery pierces the insertions of the adductors brevis and magnus, and some of its branches anastomose, anterior to the gluteus maximus, with the inferior gluteal, with the transverse branch of the medial circumflex, and with the transverse branch of the lateral circumflex, forming what is known as the crucial anastomosis. The second perforating artery pierces the adductors brevis and magnus, and then passes between the gluteus maximus and the short head of the biceps femoris into the vastus lateralis. It anastomoses with its proximal and distal fellows, and with the medial circumflex and the proximal muscular branches of the popliteal artery. The third and fourth perforating arteries pass through the adductor magnus and the short head of the biceps femoris into the vastus lateralis. Their anastomoses are similar to those of the second perforating. FIG. 780. THE ARTERIES OF THE BUTTOCK AND THE POSTERIOR ASPECT A nutrient branch to the femur is given off either from the second or third perforating artery, usually the former; an additional nutrient branch may also be supplied by the first or fourth perforating arteries. (5) The arteria genu suprema (O.T. anastomotic) arises near the termination of the femoral artery, in the distal part of the adductor canal, and divides, almost immediately, into a superficial, saphenous, and a deep (musculo-articular) branch; indeed, very frequently the two branches arise separately from the femoral trunk. (a) The saphenous branch passes through the distal end of the adductor canal with the saphenous nerve, and appears superficially, on the medial side of the knee, between the gracilis and the sartorius. It gives twigs to the integument of the proximal and medial part of the leg, and it anastomoses with the inferior medial genicular artery. (6) The musculo-articular branch runs towards the knee, in the substance of the vastus medialis, along the anterior aspect of the tendon of the adductor magnus. It anastomoses with the superior medial genicular artery, and it sends branches laterally, one on the surface of the femur and another along the proximal border of the patella, to anastomose with the descending branch of the lateral circumflex, the fourth perforating artery, the superior lateral genicular, and the anterior tibial recurrent. ARTERIA POPLITEA. The popliteal artery is the direct continuation of the femoral. It commences at the medial and proximal side of the popliteal fossa, under cover of the semimembranosus, and terminates at the distal border of the popliteus muscle, and on a level with the distal part of the tuberosity of the tibia, by dividing into the anterior and the posterior tibial arteries. From its origin the artery passes' distally, with a lateral inclination, to the interspace between the condyles of the femur, whence it is continued vertically to its termination. Relations.Anterior.-It is in contact in front and proximo-distally with the popliteal surface of the femur, the posterior part of the capsule of the knee-joint, and the fascia covering the posterior surface of the popliteus. Posterior. The artery is overlapped behind, in the proximal part of its extent, by the lateral border of the semimembranosus; it is crossed, about its middle, by the popliteal vein and the tibial (O.T. internal popliteal) nerve, the vein intervening between the artery and the nerve; whilst, in the distal part of its extent, it is overlapped by the adjacent borders of the two heads of the gastrocnemius, and is crossed by the nerves to the soleus and popliteus and by the plantaris muscle. Lateral. On its lateral side it is in relation, proximally, with the tibial nerve and the popliteal vein, then with the lateral condyle of the femur, and, distally, with the lateral head of the gastrocnemius and the plantaris. Medial.-On the medial side it is in relation, proximally, with the semimembranosus, in the middle with the medial condyle of the femur, and, distally, with the tibial nerve, the popliteal vein, and the medial head of the gastrocnemius. Popliteal lymph glands are arranged irregularly around the artery. Branches. (1) Muscular branches are given off in two sets, proximal and distal. The proximal muscular branches are distributed to the distal parts of the hamstring muscles, in which they anastomose with branches of the profunda artery. The distal muscular, or sural, arteries enter the proximal parts of the gastrocnemius, the plantaris, the soleus, and the popliteus muscles, and they anastomose with branches of the posterior tibial artery and the lower genicular arteries. (2) The genicular branches are five in number-viz., superior and inferior lateral, superior and inferior medial, and a median branch. (a) The superior lateral genicular artery passes laterally, proximal to the lateral condyle, behind the femur and in front of the biceps tendon, into the vastus lateralis, where it anastomoses with the arteria genu suprema, the descending branch of the lateral circumflex, and the fourth perforating artery; it also sends branches distally to anastomose with the inferior lateral genicular and with the anterior tibial recurrent. (b) The superior medial genicular artery passes medially, proximal to the medial condyle, behind the femur, and anterior to the tendon of the adductor magnus, into the vastus medialis. It anastomoses with branches of the arteria genu suprema and of the superior lateral genicular artery. (c) The inferior lateral genicular artery runs laterally, across the popliteus muscle and anterior to the plantaris and the lateral head of the gastrocnemius; then, turning forwards, it is joined by the inferior lateral genicular nerve, and passes to the medial side of the fibular collateral ligament. M. semitendinosus It terminates by anastomosing with its fellow of the opposite side and with the superior lateral genicular and anterior tibial recurrent arteries. A. genu superior M. gastrocnemius N. peronæus M. flexor hallucis Tendon of M. (d) The inferior medial geni cular artery passes medially, distal to the medial condyle of the tibia, along the proximal border of the popliteus and in front of the medial head of the gastrocnemius, to the medial side of the knee, where it turns forwards, between the bone and the tibial collateral ligament, and terminates anteriorly by anastomosing with its fellow of the opposite side, with the recurrent branch of the anterior tibial artery, and with the superior medial genicular artery. (e) The arteria genu media passes directly forwards from the front of the popliteal artery, pierces the central part of the posterior surface of the capsule of the knee-joint, and enters the intercondylar fossa. It supplies branches to the crucial ligaments and to the synovial membrane, and is accompanied by the medial genicular branch of the tibial nerve, and sometimes by the genicular branch of the obturator nerve. (3) Cutaneous branches are distributed to the skin over the M. peronæus brevis popliteal fossa. One of these, the superficial sural artery, runs along the middle of the back of the calf with the vena saphena parva. A. peronæa M. flexor hallucis Lig. talofibulare ARTERIA TIBIALIS POSTERIOR. posterior tibial The artery, the larger of the two terminal branches of the popliteal, commences at the distal border of the popliteus and terminates midway between the tip of the medial malleolus and the most prominent part of the heel, at the distal border of the laciniate ligament (O.T. internal annular). It ends by dividing into the medial and the lateral plantar arteries, which pass onwards to the sole of the foot. of The posterior tibial artery runs distally and medially, in the posterior part the leg, between the superficial and deep layers of muscles and covered, posteriorly, by the deep intermuscular fascia which intervenes between them. |