410 



ARTERIES OF THE UPrER LIMB. 



this mctacnr^Jal branch arises as a separate vessel, the posterior carpal being then 

 very small. 



Fig. 268. 



.1V 





Fig. 263. — Abnormal Superficial Ulnar Artery 



RISING HIGHER THAN USUAL FROM THE BRACHIAL 



(from R. Quain, and from a preparation in Allen 

 Thomson's collection). \ 



a, biceps muscle covered I33' the deep brachial fascia ; 

 h, the same fascia in the fore-arm, which has been 

 opened in a considerable extent to show the radial artery 

 subjacent to it ; c, median nerve ; d, ulnar nerve ; 1 

 on the biceps muscle, points to the brachial artery after 

 having given off an ulnar artery higher up, anil dividing 

 at 1', into the radial artery and a deep vessel correspond- 

 ing to the interosseous and a part of the usual ulnar ; 

 2, on the supinator longus muscle, points to the radial 

 artery ; 3, 3, artery wliich is given otf by the brachial in 

 the arm, and which descending upon tlie fascia takes the 

 place of the ulna at the wrist ; 3', the same continued 

 into the superficial palmar arcli, giving off digital 

 branches nearly in the usual manner, and joined by a 

 branch from the radial, 4, the superficial volar ; 5, digital 

 branches. 



The anterior ulnar carpal brancli is a very 

 small artery, which runs on the finterior sur- 

 face of the carpus beneath the flexor pro- 

 fundus, anastomoses with a similar offset from 

 the radial artery, and supplies the carpal bones 

 and articulations. 



Varieties. — Oi-igin. — In the whole number of 

 cases observed by Richard Quain. the ulnar artery 

 was found to deviate from its usual mode of vrigin, 

 j ' III g nearly in the proportion of one in thirteen. The 



/ f IK f l)rachial artery was, more frequently than the axil- 



lary, the source from which it sprang- ; indeed, the 

 examples of its origin from the main trunk at 

 different parts appeared to decrease in number in 

 proportion as the place of origin was higher up the 

 M^^^^^ l\ artery. In one case of high origin of the ulnar 



artery the vessel was connected with the brachial 

 opposite the elbow-joint by means of a transverse 

 /^ branch (Gruber, Reich. Arch., 1S71). See, on this 



\ subject, the description of the varieties of the axillary 



and brachial arteries. 



Couvftc. — The jwsiiion of the ulnar artery in the 

 fore-arm is more frequently altered than that of 

 the radial. 



In cases of high origin, it almost invariably de- 

 scends over the muscles arising from the inner con- 

 dyle of the humerus, only one exception to this nilo 

 having been met with. (R. Quain, plate ;-)G, fig. 2.) 

 In one instance where it took this course it divided 

 just below the elbow into a superficial and deep 

 branch (Gruber. loc. cit.). 

 Most commonly it is covered by the fascia of the fore-arm ; but cases also 

 occur in which the vessel rests on the fascia, and either continues in that position 

 or becomes su]3aponeurotic lower down, while the vessel thus disposed is dis- 

 tributed after the manner of the normal ulnar artery. The vessel from which 



t> 



