160 TOPOGRAPHIC AND APPLIED ANATOMY. 



and from the internal intermuscular septum; the crureus (vastus intermedius) arises from the 

 intertrochanteric line, is covered by the rectus, and is adherent in a varying degree to the vastus 

 externus and internus muscles. The quadriceps surrounds the shaft of the femur with the ex- 

 ception of the linea aspera and of the planum popliteum. All four portions of this muscle ter- 

 minate above the knee in a common tendon which, after enclosing the patella, is inserted as the 

 ligamentum patellae into the tubercle of the tibia. 



The three flexor muscles are situated posteriorly and take origin from the tuberosity of the 

 ischium. The biceps flexor cruris, in addition to its long head which arises in common with 

 the semitendinosus from the tuberosity of the ischium, has a short head from the outer lip of 

 the linea aspera; the muscle inserts into the head of the fibula. The semitendinosus muscle has 

 a long tendon which imbeds itself in a broad furrow upon the posterior surface of the semi- 

 membranosus and inserts into the tibia behind the gracilis and sartorius muscles with a broad 

 tendon extending as far forward as the tibial crest. The semimembranosus muscle arises by a 

 broad tendon from the ischial tuberosity and is inserted into the posterior surface of the internal 

 tuberosity of the tibia. 



The adductors are interposed between the extensors and flexors of the thigh ; they arise from 

 the pelvis and run to the inner lip of the linea aspera and to the internal epicondyle of the femur. 

 The common tendon contains several small orifices for the perforating arteries, which run from 

 the anterior to the posterior surfaces of the thigh, and also the large slit (hiatus adductorius} 

 for the passage of the femoral vessels into the popliteal space. The pectineus muscle commences 

 at the crest of the os pubis, converges toward the iliopsoas, and runs posteriorly to the linea 

 pectinea femoris. Since it runs posteriorly with the iliopsoas muscle, a fossa is formed below 

 Poupart's ligament, covered by the fascia lata (fossa iliopectinea), in which the large femoral 

 vessels are situated (Fig. 79). It forms the deepest portion of Scarpa's triangle (trigonum femor- 

 ale), which is bounded internally by the inner margin of the adductor longus and externally by 

 the inner margin of the sartorius. The adductor longus muscle takes origin from the pubis 

 below the pubic spine and is attached to the inner lip of the linea aspera. The adductor brevis 

 muscle passes from the inferior ramus of the pubis to the upper third of the inner lip of the linea 

 aspera; the gracilis muscle runs from the inferior pubic ramus to the tibia below the internal 

 tuberosity, extending as far forward as the tibial tubercle; the adductor magnus muscle, situated 

 most posteriorly, arises from the inferior ramus of the pubis and of the ischium as well as from the 

 ischial tuberosity and is inserted along the entire length of the inner lip of the linea aspera and also 

 by a strong tendon into the internal epicondyle of the femur. The hiatus adductorius is situated 

 above this tendon. At the junction of the middle and lower thirds of the femur an aponeurosis is 

 stretched across from the tendon of the adductor magnus to the vastus internus ; this aponeurosis 

 forms the anterior and internal wall (Fig. 80) of a canal ending at the hiatus adductorius, the 

 canalis adductorius or canal of Hunter. The posterior wall of this canal is formed by the asso- 

 ciated tendons of the adductor longus and magnus muscles and it is bounded externally by the 

 vastus internus and the femur. This canal gives passage to the femoral artery and vein. 



Femoral Artery. The femoral artery (Figs. 79-82) passes beneath Poupart's ligament 

 midway between the anterior superior spine of the ilium and the symphysis pubis and enters the 

 fossa iliopectinea. In this situation the artery may be compressed against the underlying ilio- 



