204 SURGICAL APPLIED ANATOMY. [Chap. xn. 



The nutrient artery enters the bone at its inner aspect, 

 opposite the deltoid insertion, and the anastomotic 

 vessel comes off about two inches above the bend of 

 the elbow. 



The ulnar nerve follows first the brachial artery, 

 and then a line drawn from the inner side of that 

 vessel, about the level of the insertion of the coraco- 

 brachialis to the gap between the inner condyle and 

 the olecranon. The main part of the internal cuta- 

 neous nerve is beneath the inner bicipital groove, 

 while the superficial portion of the musculo-cutaneous 

 corresponds to the lower termination of the outer 

 groove. 



The arm. The skin of the arm is thin and 

 smooth, especially in front and at the sides. It is 

 very mobile, being but loosely attached to the deeper 

 parts by a lax subcutaneous fascia. In circular am- 

 putations of the arm this looseness of the integument 

 allows it to be sufficiently drawn up by traction with 

 the hand only. It is from the integument covering 

 the anterior surface of the biceps that the flap is 

 fashioned in Tagliacozzi's operation for the restoration 

 of the nose. The fineness of the skin of this part, and 

 its freedom from hairs, render it very suitable for this 

 procedure. The scanty attachments of the skin of the 

 arm allow it to be readily torn or stripped away in 

 lacerated and contused wounds. Sometimes in these 

 lesions large flaps of integument are violently dis- 

 sected up. The looseness of the subcutaneous tissues 

 favours greatly the spread of inflammatory processes, 

 while its comparative thinness allows of the early 

 manifestation of ecchymoses. 



The limb is completely invested by a deep fascia, 

 the brachial aponeurosis, as by a sleeve. The fascia 

 is held down at the sides by the two intermuscular 

 septa which are attached along the outer and inner 

 margins of the humerus, running from the deltoid 



