250 



THE MUSCLES. 



Fig. 119. 



Structure and Attachments. The first 

 portion is generally paler than the second, 

 and is composed of longitudinal fleshy fibres 

 deeply intersected by tendinous strips. It 

 takes its origin, by its superior extremity, 

 from the dorsal angle of the scapula. The 

 anterior portion is deeper-coloured and more 

 tendinous than the other. Its superior ex- 

 tremity, included within two fibrous folds 

 resulting from the duplicature of the scapular 

 aponeurosis, is fixed, through the medium of 

 these, to the tuberosity of the scapular spine. 



These two muscular bodies unite in- 

 feriorly, and terminate together on the del- 

 toid imprint or subtrochiterian crest by 

 tendinous and muscular fasciculi. 



Relations. This muscle responds : out- 

 wardly, to the scapular aponeurosis, with 

 which it may be said to form one body; 

 inwardly, to the subspinatus, the short ab- 

 ductor of the arm, and the large and short 

 extensors of the fore-arm. 



Action. It gives a very marked abduc- 

 tion movement to the humerus, and also 

 makes it pivot outwards. It acts, besides, 

 as a flexor of that bone, when its action is 

 combined with that of the adductor of the 

 arm. It should also be considered as a 

 powerful tensor of the scapular aponeurosis. 



3., Short Abductor of the Arm, or Teres 

 Minor. (Fig. 85, 2, 3.) 



Synonyms. Scapulo-humeralis minor Gtirard. 

 (Teres minor Percivall. Scapulo-trochiterius, 

 medium and parvumLeyh.) 



Volume Situation Direction. A small 

 elongated muscle, situated below the pre- 

 ceding and the subspinatus, along the pos- 

 terior border of the scapula, whose direction 

 it follows. 



Form Structure. In its inferior half it 



1, 1, Long abductor of the arm ; 1', Its humeral 

 insertion ; 2, Superspinatus ; 3, Subspinatus ; 

 3', Its tendon of insertion ; 4, Short abductor 

 EXTERNAL MUSCLES OF THE o f the arm ; 5, Biceps ; 6, Anterior brachialis ; 



BIGHT ANTERIOR LIMB. 7^ Large extensor of the fore-arm ; 8, Short 



extensor of the fore-arm ; 9, Anconeus; 11, Anterior extensor of the metacarpus; 11', 

 Its tendon ; 12, Aponeurosis separating that muscle from the anterior brachialis ; 13, 

 Oblique extensor of the metacarpus ; 14, Anterior extensor of the phalanges ; 14', Its 

 principal tendon ; 15, The small tendinous branch it furnishes to the lateral extensor ; 

 16, Lateral extensor of the phalanges; 16', Its tendon; 17, The fibrous band it 

 receives from the carpus ; 18, External flexor of the metacarpus ; 19, Its metacarpal 

 tendon ; 20, Its supracarpal tendon ; 21, Ulnar portion of the perforans ; 22, Tendon 

 of the perforans ; 23, Its carpa lligament ; 24, Its reinforcing phalangeal sheath ; 

 25, Tendon of the perforatus. 



