MUSCLES OF THE ANTEEIOR EXTREMITY. 



79 



the upper or visceral surface of 

 the scaj)ula. It arises from a 

 bony ridge found on the upper 

 surface of the coracoid and of 

 the j^roc. coracoideus of the scap- 

 ula. The muscle runs outwards 

 and is inserted, after widening, 

 into the inner surface of the 

 crista delto'idea of the humerus ; 

 it is antagonistic to the deltoid, 

 and draws the raised arm back- 

 wards and towards the trunk. 



Fig. 70. 



Right shoulder, from below, arm strongly 

 abducted. 



cl Clavicle. 



CO Coracoid. 



d Deltoideus. 



d' Clavicular portion of deltoid. 



h Humerus. 



ss Subscajmlar muscle. 



(b) Muscles Oil I lie superficial surface. 



51. M. infraspinatus 



(Fig. ^"j, between Id and 



d)i/, Fig. 7 I /). 



Dugès, adscapulo-hnméral, 

 n. 67. 



The m. infrasjimatus re- 

 presents the VI. infraspina- 

 tus, teres major and minor oî 

 human anatomy. It is of 

 triangular form, with the 

 broad base directed in- 

 wards ; it arises from the 

 whole of the upper sur- 

 face of the suprascapula 

 except along the inner 

 border which is formed 

 of hyaline cartilage alone : 

 from this origin the fibres 

 converge outwards to a 

 fiat tendon which unites 

 with that of the m. latis- 

 simtis dorsi to be inserted 

 into the crista deltoid ea hu- 

 meri, by means of a thin, 

 triangular, tendinous ex- 

 pansion. 



Fig. 71. 



Muscles of the back and shoulder. 



c M. cucuUaris. 



dm M. depressor maxillae. 



fd Fascia dorsaUs. 



fd' Fascia dorsaUs reflected. 



i M. infraspinatus. 



l.a M. levator anguli scapulae. 



Id M. latissimus dorsi. 



r M. retrahens scapulae. 



sc M. sternocleidomastoideus. 



