ANTERIOR MUSCLES OF THE THIGH 



285 



femoral artery and branches of the femoral nerve descend into the interspace be- 

 tween the upper part of the rectus and the vastus internus; similarly, the iliaco- 

 femoral artery dips in between the rectus femoris and vastus externus. 



Blood-supply. — Femoral and iliaco-femoral arteries. 



Nerve-supply. — Femoral nerve. 



(2) Vastus externus (s. lateralis).— This lies on the outer surface of the thigh, 

 extending from the great trochanter to the patella. It is thick and wide in its 

 upper part, and becomes much thinner and narrow below. 



Fold of flank 

 Tensor fascice latce 



^^^^^ ^^^ Vastus externus 



Vastus internus Tj^^lBI^^^^^^HK^^^B^V^ Vastus intermedium 



Sartorius 



Saphenous vein 



Saphenous nerve 

 Femoral artery 



Gracilis 

 Adducio 



Peroneal nerve 

 Tibial nerve 



Seniimem- 

 hranosus 



Semilendinos 



Fig. 200. — Cross-section of Middle of Right Thigh of Horse. 



Origin. — The external border and surface of the femur, from the great tro- 

 chanter to the supracondyloid fossa. 



Insertion. — (1) The outer part of the anterior surface of the patella; (2) the 

 tendon of the rectus femoris. 



Action. — To extend the stifle joint. 



Structure. — The fibers are directed downward and forward, manj'- being in- 

 serted into the tendinous sheet which covers the side of the rectus. A bursa is 

 often found between the distal end and the patella. 



