Chap. VII] 



MUSCULAR TISSUE 



Fig. 87. — Vastus Intermedius 

 OP Right Side. (Gerrish.) 



ing the back of the arm. Each head 

 is described as a separate muscle : (1) 

 rectus femoris, (2) vastus externus, 

 (3) vastus internus, (4) vastus inter- 

 medius. 



The rectus femoris arises from the 

 ilium, the other three arise from the 

 femur. They pass downward, and 

 are inserted by one tendon to the 

 tubercle of the tibia. The tendon 

 passes in front of the knee-joint, and 

 the patella is a sesamoid bone devel- 

 oped in it. 



Action. — The quadriceps is the 

 great extensor of the leg; it also 

 flexes the thigh, and antagonizes the 

 action of the hamstring muscles. 



U< 



Fig. 88. — Gastrocnemius of 

 Right Side. (Gerrish.) 



