ANTERIOR FEMORAL REGION. 243 



VASTUS EXTERNUS. 



(Femoro-Totuleus Extemus.) 



(PL. III. 35.) 



Situated on the outer side of the rectus femoris, this muscle 

 't broad, thick, flattened laterally, and semi-ovoid, extending 

 do\TTi wards and forwards; it is fleshy, with strong tendinous 

 intersections. 



Origin. — From the external and part of the anterior aspects 

 of the shaft of the femur, and from the base of the trochanter 

 major downwards. 



Insertion. — To the upper and outer part of the patella; or 

 it may join the rectus femoris. 



Relation. — Externally with the tensor fascise latas, and gluteus 

 extemus ; internally with the rectus, crureus, and vastus intemus, 

 with which inferiorly it is intimately blended ; posteriorly with 

 the triceps abductor femoris and the femur. 

 Action. — To extend the leg. 



VASTUS INTERNUS. 



(Femoro-rotideus Intemus.) 



(Fig. 76. h) 



Corresponding to the extemus, this muscle is situated on the 

 inner side of the rectus femoris, the two forming a channel in 

 which are lodged the rectus and crureus. It is semi-ovoid, and 

 fleshy, becoming tendinous at its insertion. 



Origin. — From the neck of the femur, its an tero- internal 

 surface, and the trochanter internus. 



Insertion. — To the upper and inner side of the patella. 



Relation. — Externally with the rectus; internally with the 

 sartorius, pectineus, psoas magnus, iliacus, adductor magnus, and 

 crural fascia. 



Action. — To extend the leg. 



CRUREUS. 



(Femoro-rotuleus Medius.) 



Situated below the rectus, and between the two vasti, this 

 muscle is small, cylindrical, fleshy, and tendinous at its extremi- 

 ties ; it is separated from the vasti with difiSculty. 



