THIGH AND LEG. 321 



Because they perforate the adductor group, to reach the hamstring muscles 

 on the back of the thigh, which they supply. (Fig. 222.) 



The external circumflex supplies the muscles on the anterior part of the 

 thigh. (Fig. 223.) Its ascending branch anastomoses with the gluteal and 

 circumflex iliac; its descending branch with the superior external articular branch 

 of the popliteal artery. 



The Use of the Internal Circumflex (Fig. 223). To assist the obturator 

 artery in supplying the hip-joint and the adductor muscles, and to anastomose 

 with the sciatic and external circumflex to complete the crucial anastomosis. 



\\ r kcre, on the posterior part of tlic thigh, will you find the terminal branch of 

 the internal circumflex arterv f 



Between the quadratus femoris and the adductor magnus. 



Branches of the Superficial Femoral Artery. The superficial femoral 

 artery lies in both Scarpa's triangle and Hunter's canal surgical areas to be pres- 

 ently described. The branches given off by this artery are : muscular, to the sar- 

 torius and vastus interims ; the anastomotica magna, given off just before the 

 artery leaves Hunter's canal. 



The anastomotica niagna divides into two branches: (i) A superficial one, 

 that accompanies the long saphenous nerve, and (2) a deep one, that anastomoses 

 with the internal articular and the anterior recurrent tibial. This artery supplies 

 branches to the knee-joint. It will be found on the bone, above the condyle, 

 forming an arch with the external articular. 



Review of tlic Work on the Thigh. Thus far in the deep dissection of the an- 

 terior and lateral regions of the thigh, you have : 



1. Traced the origin, insertion, and nerve-supply of the sartorius, and lifted 

 this muscle from its bed. 



2. You have found the exact origin and insertion of the gracilis, and liberated 

 the same without doing violence to its nerves and blood-vessels. 



3. You have traced the adductor longus from origin to insertion, preserved 

 its nerves, cut the origin of the muscle, and seen the anterior division of the 

 obturator nerve lying below, on the adductor brevis muscle ; and the branches of 

 this nerve you have followed to four muscles. 



4. You have located the anterior crural nerve in a space between the psoas 

 magnus and iliacus, taken this nerve up, and traced out its branches to the muscles 

 on the front part of the thigh and to the skin covering these muscles and to the 

 joints these muscles move. 



5. You have removed the rectus from its bed, traced the same to its origins, 

 and preserved the nerve- and blood-supply ; finally, you have cut the rectus four 

 inches above the patella. 



6. You have seen that the crureus is not a separate muscle, but a part of the 

 vastus intern us. 



7. You have traced the femoral artery well down and studied its profunda 

 division. 



8. You have traced the vasti and rectus to their common insertion into the 

 tubercle of the tibia by the ligamentum patella:,. 



What to Dissect Next. (i) Cut the origin of the adductor brevis (Fig. 220), 

 gently lift the same, and see the posterior division of the obturator nerve. Trace 

 this nerve to the adductor magnus and obturator externns muscles. (2) Cut the 

 pectineus (Fig. 219) and turn it down. Now, on the outer surface of the obturator 

 externns muscle you will find the o bturator artery, anastomosing with the internal 

 circumflex, a branch of the profunda. (Fig. 223.) (3) Now you may replace 

 in this order the muscles you have cut and turned aside : (a) Pectineus, (^) 

 adductor brevis, (r) adductor longus, (d) rectus. Place the sartorius in its 

 original oblique position. 



