4 6 



THE HUMAN BODY. 



side of the fore-arm; a condyle which is received by the 

 elliptic cavity formed by the inferior extremity of the radius 

 and ulna. The hemispheric head of the humerus turns oh 

 its axis in the glenoid cavity, but this movement is prevented 

 in the hand by the elongated form of the condyle of the 

 carpus. The rotation of the ulna supplies this want, and the 

 hand turns with the bones which are attached to it in 



Fig. 15. The hand, palmar aspect. 



A. Short abductor muscle of tlie thumb, 

 above and outside of ivliich is seen 

 the opposing muscle (opponenspollicis]. 



B. Slwrtjlexor of thujnb. 



C C. Tendons of the superficial flexor 



of the fingers. 

 D. Sheath of the tendons. 

 E E. Tendons of the deep flexor. 



Fig. 1 6. The hand, dorsal aspect. 

 A. Annular ligament of the inrist. 

 B B. Tendons of the common extensor 



of the fingers. 

 C C. Tendinous expansions fastening 



tlie tendons together. 



supination and pronation. Further, it has a separate move- 

 ment in flexing the hand forward, backward, or sidewise. 

 In circumduction it describes a cone, and makes many 

 other movements in common or singly. 



The numerous muscles which determine these movements 

 form a very complicated mechanism. Their tendons are 



