TflE BRACHIAL ARTERY. 



439 



4. The anastomotic artery is a very constant branch of moderate size. 

 Arising from the brachial artery about two inches above the bend of the elbow, it is 

 directed backwards and inwards on the brachialis anticus muscle, above the inner 



Fig. 360. HIGH ORIGIN OP THE RADIAL ARTERY PROM THE BRA- 

 CHIAL, AND AN ENLARGED MEDIAN ARTERY IN THE FOREARM. 



(Tiedemann. ) 



1, on the tendon of the latissimus dorsi, points to the upper 

 part of the brachial artery ; 2, the brachial artery (ulnar-interos- 

 seous) after giving off the radial ; 3, the radial, arising in the upper 

 third of the arm and descending in its usual situation in the fore- 

 arm ; 3', its superficial volar branch ; 4, the ulnar artery in its 

 usual course, forming at 5, the superficial palmar arch, from 

 which three of the palmar digital arteries and the princeps pollicis 

 take origin, the radial supplying the branches to the index finger 

 and one side of the middle finger ; 6, superior profunda artery ; 

 7, inferior profunda ; 8, anastomotic ; 9, recurrent radial ; 10, 

 anterior interosseous, giving an unusually large median branch 

 which descends over the wrist to join the superficial palmar arch. 



condyle of the humerus, and, after perforating the 

 intermuscular septum, turns outwards behind the bone, 

 under cover of the triceps muscle, to form with the 

 superior profunda an arch across the humerus, imme- 

 diately above the olecranon fossa. In front of the 

 humerus the anastomotic artery furnishes a branch 

 which ramifies beneath the pronator teres, and anas- 

 tomoses with the anterior ulnar recurrent branch. 

 Behind the inner condyle another offset joins with the 

 posterior ulnar recurrent, and several branches are 

 given to the joint and the muscles. 



Varieties. From their comparative frequency, and 

 surgical interest, the peculiarities of the brachial artery, 

 especially those which affect its trunk, ^deserve particular 

 attention. 



Course. The brachial artery sometimes, though rarely, 

 descends, accompanied by the median nerve, towards the 

 inner condyle of the humerus, and regains its usual position 

 at the bend of the elbow by passing forwards underneath a 

 fibrous arch, from which the pronator teres in these cases 

 arises, and which descends to the inner condyle from the 

 occasional prominence called the supracondylar process. This 

 variety resembles the condition normally existing in the 

 Felidse and many other animals, in which the brachial 

 artery and median nerve are directed forwards and outwards 

 through a supracondylar foramen (see p. 95). 



Division. As an extremely rare condition, the artery has 

 been found dividing near its commencement into two vessels, 

 which unite again near the elbow, forming a single trunk 

 from which the radial and ulnar arteries are given off in the 

 usual manner. 



The most frequent change from the ordinary arrangement 

 of the brachial artery is connected with its division into ter- 

 minal branches. 



Out of 481 examples recorded by R. Quain, the vessel was 

 found in 386 to divide at its usual position, a little below 

 the elbow-joint. In one case only (and that complicated by 



another peculiarity, viz., the existence of a rax dlo-rans proceeding from the axillary to the 

 radial) was the place of division lower than usual, being between two and three inches below the 

 elbow-joint. In 64 cases the brachial artery divided above the usual point, at various heights 

 upwards to the lower border of the axilla. The branch prematurely separated from the rest 

 of the trunk in an early division is. in the proportion of nearly three cases out of four, the 



