FRONT OF THE ARM. 105 



to the deltoid muscle. These two last-named arteries, together with 

 the profunda, are frequently given off from a common trunk, instead 

 of from the axillary artery. 



DISSECTION II. 



FRONT OF THE ARM. 



An incision is to be made down the middle of the arm, to a short 

 distance below the bend of the elbow, care being taken not to divide 

 the cutaneous veins or nerves, which near the elbow are quite super- 

 iicial. The anterior portion of the arm is to be cleared from cellular 

 tissue, the numerous nerves, arteries, and veins being carefully 

 managed while the muscles are isolated from each other and the 

 surrounding parts. The insertions of the biceps and brachialis 

 anticus muscles cannot be examined until a subsequent stage of the 

 dissection. 



Iii preparing the front of the arm two large veins will 

 have been traced from the elbow upward; these are the 

 cephalic and basilic. 



The CEPHALIC VEIN ascends upon the outer side of the 

 biceps muscle to the space between the pectoralis major 

 and deltoid muscles, along which it passes to terminate 

 beneath the clavicle in the axillary vein. 



The BASILIC VEIN, superficial at the lower part, pierces 

 the fascia near the middle of the arm, and, accompanying 

 the artery at its inner side, becomes, in the axilla, the 

 axillary vein. 1 



The BICEPS MUSCLE constitutes the bulk of the arm in 

 front. It. arises by two heads, a short and a long; the 

 short head, in common with the coraco-brachialis, arises 

 from the coracoid process of the scapula ; the long head 

 arises by a round and slender tendon from the upper 

 margin of the glenoid cavity of the scapula ; this passes 

 over the head of the humerus through a special synovial 

 sheath and enters the bicipital groove ; emerging from this, 

 it expands into a broader tendon from which the muscular 

 fibres take their origin. These two heads uniting form the 

 belly of the muscle, which, terminating in a flattened tendon, 



1 The first two letters of the word "biceps," that being the muscle 

 with which this vein is in relation, will give the student a mnemonic 

 aid to retain in his mind the relative position of the basilic and 

 cephalic veins. (B. I. basilic, internal.) 



