MUSCLES OF THE ANTERIOR LIMBS. 



317 



mion, and the inferior border of the scapular spine for the whole of its width ; below, it i» 

 attached, through the medium of a tendon, to the deltoid imprint. 



By their disposition, the supra-spinatus, infraspinatus, and subscapularis resemble the 

 muscles of Carnivora. The teres major, after establishing relations with the latissimus dorsi, 

 as in Solipeds, is fixed into the inner lip of the bicipital groove. 



Muscles of the Arm. 



These muscles, grouped around the humenis, are attached to the forearm by 

 their inferior extremities. Those situated in front flex this portion of the limb, 

 while those behind extend it. The first form the 

 anterior brachial region; the second, the posterior I'lg. 180. 



brachial region. 



A, Anterior Brachial Region. 



This region is composed of only two muscles — the 

 lo7ig and short flexors of the forearm. 



1. Long Flexor of the Forearm (Flexor 

 Brachii,or Brachial Biceps) (Figs. 128, 159, 181). 



Synonyms. — Coraco-cubitalis, or coraco-radialis, according 

 to Girard. (Scapula- or coraco-radialis — Leyh.) 



Preparation. — Place the limb on its internal face, throw 

 back the brachial insertion of the mastoido-humeralis, pectora- 

 lis auticus, and pectoralis transversus, over the external muscles 

 of the forearm ; excise, lengthways, the inferior extremity of 

 the supra-spinatus, to show the originating tendon of the muscle. 

 The inferior insertion may be studied with that of the short 

 flexor muscle. 



Form — Situation — Direction — Structure. — A long, 

 cylindrical muscle, thick m its middle portion, bifid 

 inferiorly, situated in front of the humerus, in an 

 oblique direction downwards and backwards, tendinous 

 at its two extremities, divided by a great number of 

 strong fibrous intersections, one of which, nearly 

 central and much more considerable than the others, 

 is a veiy resisting cord that traverses the muscle 

 throughout its length, and becomes continuous with 

 the tendons at its extremities. 



Attachments. — This muscle has its origin at the 

 base of the coracoid process by a superior, round, and 

 thick tendon (Fig. 128, 6) that reaches the bicipital 

 groove, on which it is moulded in becoming fibro-cartilaginous, and over which 

 it glides by means of a synovial sac, to be inflected backwards and confounded 

 with the body of the muscle. Its inferior tendon, extremely short and strong, 

 terminates on the superior and internal tuberosity of the radius — the bicipital 

 tuberosity — in becoming united to the capsular ligament of the elbow-joint, and 

 insinuating itself beneath the internal ligament of this articulation. At its 

 origin, this tendon gives off a somewhat resisting fibrous band, which is spread 

 over the surface of the anterior extensor of the metacarpus, and is confounded 

 with the antibrachial aponeurosis. 



Relations. — It covers an adipose cushion, which separates it from the capsule 

 23 



MUSCLES OF ANTERIOR ASPECT 



OF man's upper arm. 



1, Coracoid process of scapula ; 

 2, coraco-clavicular liga- 

 ment (trapezoid), passing up- 

 ward to clavicle ; 3, coraco- 

 acromial ligament, passing 

 to acromion ; 4, subscapu- 

 laris ; 5, teres major ; 6, 

 coraco-brachialis ; 7, biceps ; 

 8, upper end of radius ; 9, 

 brachiaiis anticus ; 10, in- 

 ternal head of triceps. 



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