32 



ANATOMY FOE- NUftSES.' 



[CHAP. IV. 



etu 



direction is vertical and parallel 

 with the bone of the opposite side ; 

 but in the female it has a slight 

 oblique direction outwards, to com- 

 pensate for the oblique direction of 

 the femur inwards. The upper ex- 

 tremity is large, and expanded into 

 two lateral eminences with concave 

 surfaces which receive the condyles 

 of the femur. The lower extrem- 

 ity is much smaller than the upper ; 

 it is prolonged downwards on its 

 inner side into a strong process, 

 the internal malleolus. It articu- 

 lates with the fibula and one of the 

 bones of the ankle. 



The fibula is situated at the outer 

 side of the leg. It is the smaller 

 of the two bones, and, in propor- 

 tion to its length, the most slender 

 of all the long bones : it is placed 

 nearly parallel with the tibia. The 

 upper extremity consists of an ir- 

 regular quadrate head by means of 

 which it articulates with the tibia. 

 The lower extremity is prolonged 

 downwards into a pointed process, 

 the external malleolus, which lies 

 just beneath the skin. It articu- 

 lates with the tibia and one of the 

 bones of the ankle. 



The tarsus, or ankle, like the 



FIG. 23.-THE TIBIA AND FIBULA, carpus, or wrist, is composed of 

 o, tibia; /, fibula; etu and itu, lat- small pieces of bone united by 



eral eminences for reception of con- ,. ,-, , ^ 



dyies of femur; h, head of fibula; ligaments, but the tarsal bones 



e,n, external malleolus ; im, internal differ from the carpal in being 

 malleolus. r 



larger and more irregularly shaped. 



The largest and strongest of the tarsal bones is called the 

 os calcis, or heel bone ; it serves to transmit the weight of 

 the body to the ground, and forms a strong lever for the 



em 



im 



