182 THE UPPEK EXTREMITIES. 



sometimes affect the metacarpals and the phalanges, 

 tuberculosis and syphilis. Both cause swelling of the 

 bones. 



Muscles of the Forearm. The chief groups of muscles 

 on the forearm are the flexors and pronators on the an- 

 terior surface and the extensors and supinators on the 

 posterior surface. In general the flexors and pronators 

 take their origin from on or around the internal con- 

 dyle, while the extensors and supinators arise on or 

 around the external condyle. Where not otherwise 

 stated it will be understood that such is their origin. 

 In a general way they may by grouped as follows: 



ANTERIOR SURFACE. 



[ flexor carpi radialis 



Flexors of wrist j flexor carpi ulnaris 



( palmaris longus 



f flexor sublimis digitorum 

 Flexors of fingers . , 



[ flexor profimdus digitorum 



Flexor of thumb flexor longus pollicis 



f pronator radii teres 

 Pronators of hand 



[ pronator quadratus 



POSTERIOR SURFACE. 

 Extensor of forearm anconeus 



{extensor carpi radialis longior 

 extensor carpi radialis brevior 

 extensor carpi ulnaris 

 extensor ossis metacarpi pollicis 



Extensors of thumb 



extensor primi internodii pollicis 



extensor secundi internodii pollicis 

 Extensor of fingers extensor communis digitorum 



Extensor of index finger extensor indicis 

 Extensor of little finger extensor minimi digiti 



f supinator longus 



Supinators of hand . 



[ supmator brevis 



