Chap. VII] 



MUSCULAR TISSUE 



115 



Gluteus maximus arises from the ilium, sacrum, and coccyx, 

 and is inserted into the great trochanter of the femur. 



Action. — It is a powerful extensor of the hip-joint. It also 

 rotates the femur outward, and adducts the thigh. 



Gluteus medius and gluteus minimus are under the gluteus 

 maximus and almost entirely covered by it. They arise from the 

 outer surface of the ilium and are inserted into the great trochanter. 



Action. — Abduction of the thigh, and when the thigh is flexed, 

 inward rotation. 



Adductors. — The four adductor muscles are called respectively 

 magnus (great), longus (long), brevis (short), and gracilis (slender). 

 They are situated on the inner 

 side of the thigh. They arise 

 from different portions of the 

 pubic bone, and the first three 

 are inserted into the inner side 

 of the femur. The gracilis is 

 inserted into the shaft of the 

 tibia. 



Action. — The magnus, lon- 

 gus, and brevis adduct, rotate, 

 and flex the thigh. The gra- 

 cilis adducts the thigh and 

 flexes the leg. 



Sartorius. — The sartorius, 

 or tailor's muscle, is a long, rib- 

 bon-like muscle situated on the 

 front of the thigh. It crosses 

 the thigh obliquely from its 

 origin in the ilium to its insertion in the tibia. It was formerly 

 supposed to be the muscle principally concerned in producing the 

 posture assumed by the tailor in sitting cross-legged, hence its name. 



Action. — It flexes the leg, and helps in rotation and abduction 

 of the thigh. 



Biceps. — The biceps arises by two heads, one from the ischium, 

 and the other from the posterior surface of the femur. It is in- 

 serted into the head of the fibula and the outer tubercle of the tibia. 



Semitendinosus and Semimembranosus. — They arise from 

 the ischium, and are inserted into the upper and inner part 



Fig. 84. 



Gluteus Maximus of Right 

 Side. (Gerrish.) 



