FRONT OF THE ARM 



79 



The dissector has al- 

 ready taken notice of the 

 lace rt us fibrosus, and has 

 separated it artificially from 

 the fascia brachii above, 

 and from the fascia anti- 

 brachii below. Observe 

 now that it springs from 

 the anterior margin of the 

 tendon of the biceps brachii, 

 and that it likewise receives 

 some muscular fibres from 

 the short head of the 

 muscle. 



M. Brachialis (O.T. 

 Brachialis Anticus). The 

 brachialis arises from the 

 entire width of the anterior 

 surface of the distal half of 

 the body of the humerus, 

 from the medial inter- 

 muscular septum, and from 

 a small part of the lateral 

 intermuscular septum 

 above the brachioradialis. 

 The origin from the bone 

 is prolonged upwards in 

 two slips which partially 

 embrace the insertion of 

 the deltoid. The fibres 

 converge to be inserted 

 into the base of the coro- 

 noid process of the ulna 

 by a short, thick tendon. 

 The muscle lies partly 

 under cover of the biceps 

 brachii, but projects be- 

 yond it on either side. It 

 is overlapped on its medial 

 side by the pronator teres, 

 and on the lateral side by 1 

 the brachioradialis and ex- 



Supraspinatus 



Subscapularis 



' Latissimus dorsi 



Pectoralis major 



Teres major 



r . Deltoid 



L Coraco-brachialis 



-- Brachioradialis 



Extensor carpi 



radialis 



longus 





Extensors 



Pronator radii teres 

 and flexors . 



J. 33. Anterior aspect of Humerus with 

 Muscular Attachments mapped out. 



