DISSECTION OF THE POSTERIOR LIMB. 59 



muscles, and is covered by the deep inguinal lymphatic glands. It is 

 closely related to the femoral vein, which lies beneath and slightly pos- 

 terior to it, except at the brim of the pelvis, where the vein is imme- 

 diately posterior to the artery. In the present stage of the dissection 

 the vessel disappears between the upper and lower insertions of the 

 adductor magnus, where it will subsequently be followed. The following 

 collateral branches of the femoral are here seen : — 



1. The Profunda or Deep Femoral Artery. This branch is given 

 off luider Poupart's ligament at the pelvic brim. At its origin it 

 usually forms a short common trunk with the prepubic artery. It 

 passes downwards and backwards under the pectineus, and will be 

 followed in the next stage of the dissection. 



2. Muscular Branches. The largest of these is a vessel of consider- 

 able size for the supply of the quadriceps extensor cruris muscle. It 

 comes off at about the same level as the profunda, which it generally 

 exceeds in volume; and passing over the psoas magnus and iliacus, and 

 under the sartorius, it penetrates between the rectus femoris and vastus 

 internus, in company with the anterior crural nerve. Other innominate 

 arteries of smaller size enter the vastus internus, pectineus, gracilis, 

 sartorius, and adductors. 



3. The Saphena Artery already described (page 57). 



4. The Nutrient Artery of the Femur is given off at the tendon of 

 insertion of the pectineus. 



5. An Articular branch, of slender volume, descends between the vastus 

 internus and adductor magnus to the stifle-joint. 



The Femoral Vein ascends in close company with the artery, and 

 receives branches which correspond more or less exactly to those just 

 described. At the brim of the pelvis it lies posterior to the artery, and 

 is continued upwards as the external iliac vein. 



The Anterior Crural Nerve (Plate 13) is derived from the lumbo- 

 sacral plexus. It descends between the psoas magnus and parvus ; and 

 passing over the common termiijation of the iliacus and psoas magnus, 

 where it is covered by the sartorius, it splits into a bundle of branches 

 that together penetrate between the vastus internus and rectus femoris 

 to supply the mass of the quadriceps extensor cruris. While under 

 cover of the sartorius it gives off the internal saphena nerve already 

 described. 



Directions. — The pectineus, adductor parvus, adductor magnus, and 

 semimembranosus muscles are now to be cleaned and isolated. These 

 muscles succeed each other from before to behind in the order named. 

 Some little difficulty may be experienced in finding the line of separa- 

 tion between the two adductoi'S, but a reference to Plate 13 will prove 

 of some assistance. Moreover, the fibres of the small adductor are of a 

 paler colour than those of the adductor magnus. 



