64 LANDMARKS MEDICAL AND SURGICAL. 



is also a small subcutaneous bursa over each of the con- 

 dyles. 



The vertical extent of the elbow joint is limited, above 

 by a line drawn from one condyle to the other ; below, by 

 a line corresponding to the lowest part of the head of the 

 radius. 



138. Interosseous arteries. About one inch below the 

 head of the radius, the ulnar artery gives off the common 

 interosseous ; and this divides, about half an inch lower, into 

 the anterior and posterior interosseous. Thus, in amputating 

 the forearm, say two inches below the head of the radius, four 

 arteries at least would require ligature. 



By flexion of the elbow to the utmost, the circulation 

 through the brachial artery can be arrested ; but the position 

 is painful, and can be tolerated only for a short time. 



Lymphatic gland. There is a small lymphatic gland 

 just above the inner condyle, in front of the intermuscular 

 septum. It is the first to take alarm in poisoned wounds of 

 the hand. 



THE FOREARM AND WRIST. 



139. Ulna. The edge of the ulna can be felt subcuta- 

 neous from the olecranon to the styloid process (in supina- 

 tion). Any irregularity could be easily detected. The 

 styloid process of the ulna does not descend so low as the 

 styloid process of the radius, or it would impede the free 

 abduction of the hand. Its apex is on a level with the radio- 

 carpal joint. The head of the ulna is plainly felt and seen 

 projecting at the back of the wrist, especially in pronation of 

 the forearm. It then lies between the tendons of the extensor 

 carpi ulnaris and extensor minimi digiti. There is often a 

 subcutaneous bursa over it. 



140. Radius. The upper half of the shaft of the radius 

 is so covered by muscles that we cannot feel it ; the lower 

 half is more accessible to the touch, especially just above and 

 just below the part where it is crossed by the extensors of 

 the thumb. Its styloid process is readily felt, and made all 



