BRANCHES OF THE HUMERAL ARTERY. 273 



The Humeral Artery* 



The direction of this artery is influenced by the position of the 

 OS humeri. When the arm hangs down, with the palm of the 

 hand presenting forward, this direction is somewhat spiral. The 

 situation of the artery is on the inside of the biceps muscle, and 

 between that muscle and the triceps extensor. It also continues 

 very near and on the inside of the tendon of the biceps, and 

 under the Aponeurosis which proceeds from that tendon. In 

 consequence of the spiral or oblique course of the artery, its 

 direction would be from the inside of the tendon of the biceps 

 to the radial side of the fore-arm ; but soon after it passes across 

 the joint of the elbow, it divides into two branches: one which 

 preserves, for some distance, the direction of the Main TrunJc, 

 is called the Radial artery : the other, which inclines obliquely 

 downwards and towards the ulna, is the Common Trunk of the 

 Ulnar and Interosseal Arteries. 



During this course, the Humeral artery sends off several 

 branches to the muscles and other parts on the os humeri. The 

 largest of them is denominated the Profunda Humeri or Spi- 

 ralis. This artery very often arises as high as the insertion of 

 the latissimus dorsi, and passing between the heads of the tri- 

 ceps extensor muscle, proceeds downwards under that muscle 

 in a spiral direction, towards the external or radial condyle. 

 It sends several branches to the triceps and the contiguous 

 muscles, and one considerable branch, which is generally called 

 the Profunda Minor, to the parts contiguous to the internal 

 condyle. The ramifications of these branches near the condyle 

 frequently anastomose with small branches of the radial and 

 ulnar arteries.f 



A small branch frequently arises from the Humeral artery, at 

 a short distance from the Profunda Humeri, •which sends a rami- 

 fication to the medullary foramen of the os humeri. This vessel 

 is, therefore, denominated Arteria Nutritia. 



* It is called the Brachial Artery by several writers. 



f The profunda sometimes originates from the scapular, or one of the cir- 

 cumflex. The profunda minor sometimes has a distinct and separate origin, 

 lower down than the other. 



