FOREARM AND HAND 127 



by the coraco-humeral ligament). By combination of the 

 angular movements, in regular sequence, circumduction is 

 produced ; and rotation of the humerus, to the extent of 

 quarter of a circle, occurs also. 



The muscles chiefly concerned in producing these move- 

 ments are : flexion the pectoralis major and the anterior 

 part of the deltoid ; extension latissimus dorsi, posterior part 

 of the deltoid, and the teres major; abduction the deltoid 

 and supraspinatus ; adduction pectoralis major, coraco- 

 brachialis, teres major, and latissimus dorsi ; rotation medially 

 subscapularis, pectoralis major, latissimus dorsi, teres 

 major ; rotation laterally infraspinatus, and teres minor ; 

 circumduction is produced by the action of different combina- 

 tions of these muscles. 



The relations of the capsule are shown in Figs. 52, 53. 



FOREARM AND HAND. 



The skin has already been removed from the forearm and 

 hand, and the cutaneous veins and nerves have been exposed 

 and studied, but before proceeding with the deeper dissection 

 the dissector should re - examine the cutaneous veins and 

 nerves. 



Vense Superficiales. The two large superficial veins, the 

 basilic and the cephalic, both spring from the venous arch 

 on the dorsum of the hand in which the superficial veins 

 from the fingers terminate (p. 63), and they are reinforced 

 by numerous tributaries from the dorsal and volar surfaces of 

 the limb. The basilic vein curves round the proximal part 

 of the ulnar border of the forearm on its way towards the 

 arm, whilst the cephalic vein turns round the distal part of 

 the radial border (Figs. 31, 32). 



Nervi Cutanei. Two nerves supply the skin of the volar 

 aspect of the forearm : the volar branch of the medial cutaneous 

 nerve of the forearm on the medial side, and the lateral 

 cutaneous continuation of the musculo- cutaneous nerve on the 

 lateral side. 



Three nerves supply the skin on the dorsal aspect of the 

 forearm : the dorsal branch of the medial cutaneous nerve of the 

 forearm on the medial side, branches of the lateral cutaneous 

 nerve on the lateral side, whilst the intermediate area is 



