106 ANATOMY OP UPPER EXTREMITY, ETC. 



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penetrates between the muscles of the forearm to be ii 

 serted into the tubercle of the radius. An aponeurotic 

 expansion continuous with the fascia of the forearm, is 

 given off at the elbow from the outer side of the tendon of 

 insertion, protecting the brachial artery which lies just 

 beneath it. The biceps sometimes has &'third head, which 

 consists of a bundle of muscular fibres from the front of the 

 humerus, usually connected with the brachialis anticus, and 

 which unites with the lower part of the belly of the muscle 

 on its inner side. Two or three muscular branches of the 

 brachial artery enter this muscle. The inner" border of the 

 biceps, at its middle, is the guide to the brachial artery, 

 which lies just within its edge and inside the median nerve. 



The CORACO-BRACHIALIS MUSCLE lies at the inside of the 

 biceps ; it arises from the coracoid process, between the 

 pectoralis minor and the short head of the biceps, and is 

 inserted into a rough line on the inner side of the middle 

 of the humerus. 



The BRACHIALIS ANTICUS MUSCLE lies beneath the 

 biceps on the lower half of the arm ; it arises from the 

 humerus by muscular fibres which embrace the insertion of 

 the deltoid, and is inserted into the coronoid process of the 

 ulna. Its insertion cannot be fully seen until the forearm 

 is dissected. 



The BRACHIAL ARTERY extends from the lower border of 

 the conjoined tendons of the latissimus dorsi and teres 

 major to the bend of- the elbow, where it divides into the 

 radial and ulnar arteries; it lies along the inner border of 

 the coraco-brachialis and biceps muscles, and is superficial 

 in nearly its whole extent; the basilic vein lies in front of 

 the artery and the ulnar nerve along its inner side; the 

 median nerve lies first upon its outer side, then crosses it 

 and descends to the elbow on its inner side. 



The normal condition of this trunk may be varied by 

 what- is called its "high division;" that is, instead of 

 originating at the usual point, the radial, ulnar, or inter- 

 osseous arteries, one or all, are given off higher up, along 

 the course of the brachial or even of the axillary artery. 

 Sometimes the radial and ulnar, when thus given off, are 

 connected by a transverse branch. Occasionally the brachial 

 arteiy descends with the median nerve to a point near the 

 inner condyle, where it turns around a prominence of bone 1 



1 Called the "supra-condyloid process" of the humerus. 



