152 SURGICAL ANATOMY OF 



limb is pronated or supinated, the roundness of its lateral 

 boundaries being due to the flexors and pronator teres on 

 the inner, and the supinators and extensors on the outer. 

 The bones, the radius and ulna, are capable of being 

 felt almost entirely throughout the region, particularly 

 the ulna, the posterior border of which is subcutaneous 

 from the olecranon to the styloid process ; the radius, 

 however, has its shaft thickly covered with muscles, and 

 is felt with greater difficulty, and the several tendons of 

 the muscles clothing them are readily seen on putting 

 them in action. The radial and ulnar pulses are seen 

 in the lower part, while the radial can be felt in the 

 upper along the inner border of the mass of muscles at 

 the radial side. 



Dissection. On removing the skin, which is thin and 

 smooth, and provided with hairs, the subcutaneous fascia 

 is met with, containing a great deal of fat, in which lie 

 the superficial veins and cutaneous nerves and lym- 

 phatics. Beneath this layer is the antebrachial apo- 

 neurosis, continuous with that already described at the 

 elbow. It is dense, tough, and by its prolongation forms 

 fibrous sheaths for the muscles and other structures of 

 the region. This general antebrachial aponeurosis may 

 be considered as forming into two chief compartments, 

 attached laterally to the radius and ulna; thus the an- 

 terior is bounded by the anterior lamina, the anterior 

 surfaces of the radius, ulna, and interosseous membrane, 

 and the posterior by the posterior surface of these bones 

 and the interosseous membrane, and by the aponeurosis. 



The anterior aspect of the forearm, according to this 

 arrangement, supposing the bones to be midway between 

 pronation and supination, contains from the surface to 

 the interosseous membrane, the integument of the forearm, 



