QUADRICEPS EXTENSOR CRURIS MUSCLE. 



237 



Relations. — In this long- course the muscle is directed over the anteiior part 

 of the thigh, obliquely inv/ards in the upper thii'd, and vertically at the inner 

 aspect of the limb as far as the knee ; 

 below this it timis obliquely forwards to 

 its place of attachment. The tendon of 

 insertion, broad and expanded, covers the 

 tendons of the gi-acilis and semitendi- 

 nosus (a sjoiovial bui'sa being interposed), 

 and gives off one expansion which 

 strengthens the capsule of the knee- 

 joint by becoming incorporated with it, 

 and another which blends with the fascia 

 of the leg. 



Fig. 188. — SupEKFiciAL Muscles of thf, 

 Fkont op the Thigh. (A. T.) \ 



a, anterior part of the crest of the ilium ; 

 I), symphysis pubis ; c, patella ; d, the an- 

 terior tuberosity of the tibia ; 1, the inser- 

 tion of the external oblique muscle into tlie 

 iliac crest ; 2, its aponeurosis at the linea 

 semilunaris ; 3, the external abdominal ring ; 

 4, the gluteus medius ; 5, tensor vagin;^ 

 femoris at the place of its insertion into 

 a portion of the fascia lata, which has 

 been removed between 5 and 5', which latter 

 part is seen descending to be attached to the 

 tibia and fibula ; 6, the sartorius ; 6', the 

 insertion of the sartorius ; 7, psoas and iliacus 

 conjoined ; 8, pectineus ; 9, adductor longus ; 

 10, gracilis ; 11, part of the adductor magnus 

 12, vastus externus ; 13, rectus femoris ; 14, 

 vastus internus ; 1 4', its continuation on the 

 outer side below ; 15, the biceps flexor cruris. 



The sartorius is covered only by the 

 fascia lata and the integument. It passes 

 over the iliacus and rectus femoris mus- 

 cles, the anterior crural nerve and fe- 

 moral vessels, the pectineus, the adductor 

 longus, adductor magnus, vastus internus 

 and semitendinosus muscles. The inner 

 border of this muscle and the most pro- 

 jecting part of the adductor longvis form 

 the sides, and Poupart"s ligament forms 

 the base, of a triangular space in the . 

 upper third of the thigh, through the 

 middle of which the femoral ai'tery passes. 

 This usually receives the name of Scarpa's 

 triangle. 



Varieties — The sartorius has frequently 

 been found divided into two parts similarly 

 attached ; or the lower muscle is inserted 

 into the femiur or into the tendon of the 

 normal one. The tendon of insertion has 



been found to end in the fascia lata or in the capsule of the knee-joint. Total 

 absence of the muscle has also been noted. 



The quadriceps extensor cruris, the extensor muscle of the knee, 

 is divisible into four parts, one of which, the rectus femoris, descends 

 from the hip-bone and remains distinct, -while the other three, 



