THE THIGH. 

 FIG. 82. A cross-section above the middle of the thigh. 



n- 



pectineal eminence; care must be taken to avoid pressing upon the vein, which is situated 

 ternally. We differentiate three portions of the artery. The first portion extends from Pou- 

 part's ligament to the sartorius muscle and is situated in Scarpa's triangle. In addition to the 

 superficial vessels previously mentioned (see page 121) the femoral artery gives off the large 

 trunk of the projunda jemoris (Fig. 81). This vessel usually arises about three centimeters below 

 Poupart's ligament ; it may, however, commence at a higher level, and this point must be borne 

 in mind in ligating the femoral artery. The two large circumflex arteries arise here as well as the. 

 three perforating arteries for the flexor surface. From the iliopectineal fossa the artery runs 

 in the groove between the vastus internus and the adductors, covered only by the fascia lata, 

 and then passes beneath the sartorius muscle. It consequently leaves Scarpa's triangle and 

 enters upon the second portion of its course, which is situated below the sartorius muscle. In 

 this situation it may be readily exposed by the aid of a line drawn from the middle of Poupart's 

 ligament to the inner condyle of the femur and by displacing the sartorius internally. The 

 third portion of the vessel is found in Hunter's canal (canalis adductorius, see page 160). Be- 

 fore entering the canal, or in the canal itself, the artery gives off the anastomotica magna, which 

 runs to the knee-joint. 



Femoral Vein. The femoral vein (Fig. 79) is to the inner side of the artery above, but 

 gradually passes behind it, so that at the entrance to Hunter's canal the vein is almost entirely 

 concealed by the artery (Fig. 80). The nearer we approach to the knee, the firmer becomes 

 the connective tissue between the artery and the vein, for which reason the ligation of the artery 

 in this situation is more difficult on account of the necessary isolation of the vein. 



Anterior Crural Nerve. The anterior crural nerve (Fig. 79), the motor nerve for the quad- 

 riceps and the sartorius muscles, passes to the thigh through the lacuna musculorum (see page 

 157 and Fig. 76) to the outer side of the femoral artery and separated from it by the iliopecti- 

 neal fascia. It is scarcely endangered by the ligation of the artery, and divides just below Pou- 

 part's ligament into cutaneous and muscular branches. The longest branch is the cutaneous 

 nerve, designated as the long saphenous (Figs. 80 and 82), which accompanies the femoral artery 

 to Hunter's canal; the nerve then passes through the anterior wall of the canal, runs beneath the 

 sartorius muscle, perforates the fascia lata behind the insertion of the sartorius, and accompanies 

 the long saphenous vein to the internal malleolus. 



Sciatic Nerve. The sciatic nerve, the motor nerve of the flexors, and often made familiar 

 to the laity by sciatica, leaves the pelvis through the infrapyriform foramen (see page 146 and 

 Figs. 78 and 82); it lies at first upon the obturator internus and the two gemelli muscles be- 

 neath the gluteus maximus, and then upon the quadratus femoris between the great trochanter 

 and the tuberosity of the ischium. It becomes superficial at the lower border of the gluteus 

 maximus muscle and for a short distance is covered only by the skin and fascia. In this situa- 

 tion the nerve is accessible to electric and surgical treatment. In order to expose the nerve the 

 patient is placed upon the abdomen and a line is drawn from the great trochanter to the tuber- 

 osity of the ischium ; an incision is now made parallel to the inferior margin of the gluteus maxi- 

 mus at the junction of the inner and middle thirds of this line. It must be remembered that 



