THE FRONT OF THE ARM 



109 



The " base " is an imaginary line drawn between the 

 two epicondyles of the humerus. The medial border, 

 formed by the lateral margin of the pronator teres muscle 



Lateral end of clavicle 

 ^__ Margin of acromion 



Pectoralis major 

 Cephalic vein 



Deltoid 



Cutaneous branches of Axillary 

 nerve piercing deltoid 



Lateral brachial cutaneous branch 

 of axillary (O.T. circumflex) nerve 



Biceps brachii 

 Lateral head of triceps 



Brachialis 



Proximal branch of dorsal 

 cutaneous nerve of forearm 



Cephalic vein 



Distal branch of dorsal cutaneous 

 nerve of forearm 



Brachio-radialis 

 Tendon of triceps 



Olecranon 

 Extensor carpi radialis longus 



FIG. 46. The Deltoid Muscle and the lateral aspect of the Arm. 



descending from the medial epicondyle, and the lateral 

 border, formed by the medial margin of the brachio-radialis, 

 as it descends from the lateral supra - epicondylar ridge, 

 meet distally at the apex where the brachio-radialis overlaps 



