70 ANATOMY FOR NURSES. [CHAP. VI. 



The sartorius, or tailor's muscle, is a long, ribbon-like muscle, 

 the longest in the body: it crosses the thigh obliquely from 

 its origin in the ilium to its insertion in the tibia. It is supposed 

 to be the muscle principally concerned in producing the posture 

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



The internal femoral or adductor muscles occupy the internal 

 portion of the thigh : they are all adductors of the thigh. 



The tibialis anticus, the extensors, and the peroneal muscles 

 cover the front and outer side of the leg. The gastrocnemius 

 and the soleus, the flexors, and the tibialis posticus, cover the back 

 of the leg. The action of the tibialis anticus and of one of the 

 three peroneal muscles is to flex the ankle, while the action of 

 the tibialis posticus and the other peroneal muscles is to extend 

 the ankle. The flexors and extensors act on the toes. 



The gastrocnemius and soleus form the calf of the leg; they 

 are inserted into a common tendon, the tendo Achillis, which is 

 the thickest and strongest tendon in the body, and is inserted 

 into the os calcis, or heel bone. The muscles of the calf possess 

 considerable power, and are constantly called into use in stand- 

 ing, walking, dancing, and leaping ; hence the large size they 

 usually present. 



The sole of the foot is protected by a fascia, called the plantar 

 fascia, which is very strong, and the densest of all the fibrous 

 membranes. 



Most of the muscles are covered closely by sheets of fibrous 

 connective tissue (fasciae), and this deep layer of tissue forms a 

 nearly continuous covering beneath the superficial or subcu- 

 taneous layer of areolar connective tissue, which in a former 

 chapter we saw to be continuous over the whole of the body. 

 Parts of the deep fasciae in the vicinity of the larger' joints, as 

 at the wrist and ankle, become blended into tight transverse 

 bands which serve to hold the tendons close to the bones, and 

 receive the name of annular ligaments. 



