

590 



ANGIOLOGY 



Med. antibrach. 

 cutan. nerve 



'Radial nerve, 



A. prof undo, 

 brachii 



divides opposite the neck of the radius into the radial and ulnar arteries ; it is covered, 

 in front, by the integument, the superficial fascia, and the vena mediana cubiti, 

 the last being separated from the artery by the lacertus fibrosus. Behind it is 

 the Brachialis which separates it from the elbow-joint. The median nerve lies 



close to the medial side of the; 

 artery, above, but is separated 

 from it below by the ulnar head of 

 the Pronator teres. The tendon of 

 the Biceps brachii lies to the lateral 

 side of the artery; the radial nerve 

 is skuated upon the Supinator, an 

 concealed by the Brachioradialis. 



Peculiarities of the Brachial Artery as 

 Regards its Course. The brachial artery, 

 accompanied by the median nerve, may 

 leave the medial border of the Biceps 

 brachii, and descend toward the medial 

 epicondyle of the humerus; in such cases 

 it usually passes behind the supracondylar 

 process of the humerus, from which a 

 fibrous arch is in most cases thrown 

 over the artery; it then runs beneath or 

 through the substance of the Pronator 

 teres, to the bend of the elbow. This 

 variation bears considerable analogy with 

 the normal condition of the artery in 

 some of the carnivora; it has been re- 

 ferred to in the description of the hu- 

 merus (p. 212). 



As Regards its Division. Occasionally, 

 the artery is divided for a short distance 

 at its upper part into two trunks, which 

 are united below. Frequently the artery 

 divides at a higher level than usual, and 

 the vessels concerned in this high division 

 are three, viz., radial, ulnar, and inter- 

 osseous. Most frequently the radial is 

 given off high up, the other limb of the 

 bifurcation consisting of the ulnar and 

 interosseous; in some instances the ulnar 

 arises above the ordinary level, and the 

 radial and interosseous form the other 

 limb of the division; occasionally the in- 

 terosseous arises high up. 



Sometimes, long slender vessels, vasa 

 aberrantia, connect the brachial or the 

 axillary artery with one of the arteries 

 of the forearm, or branches from them. 

 These vessels usually join the radial. 



Varieties in Muscular Relations. The brachial artery is occasionally concealed, in some part 

 of its course, by muscular or tendinous slips derived from the Coracobrachialis, Biceps brachii, 

 Brachialis, or Pronator teres. 



Collateral Circulation. After the application of a ligature to the brachial artery in the upper 

 third of the arm, the circulation is carried on by branches from the humeral circumflex and sub- 

 scapular arteries anastomosing with ascending branches from the profunda brachii. If the 

 artery be tied below the origin of the profunda brachii and superior ulnar collateral, the circula- 

 tion is maintained by the branches of these two arteries anastomosing with the inferior ulnar 

 collateral, the radial and ulnar recurrents, and the dorsal interosseous. 



Branches. The branches of the brachial artery are: 



Profunda Brachii. Superior Ulnar Collateral. 



Nutrient. Inferior Ulnar Collateral. 



Muscular. 



Sup. ulnar collateral 

 artery 



Inf. ulnar collateral 

 artery 



FIG. 525. The brachial artery. 



