1418 



CLINICAL AND TOPOGRAPHICAL ANATOMY 



arrangement of the superficial veins as usually described is by no means constant (fig. 1136). 

 Tiie median basilic is the vein usually chosen for venesection, owing to its larger size and its 

 being firmly supported by the subjacent bicipital fascia which separates it from the brachial 

 artery; but the median cephalic is the safer. The median basilic is crossed by branches of 

 the medial antibrachial (internal) cutaneous nerve, while those of the musculo-cutaneous lie 

 under the median cephalic. In the semiflexed position, the fold of the elbow is seen, a little 

 above the level of the joint. This forms the base of the triangular fossa below the elbow, the 

 lateral side corresponding to the brachio-radialis, the medial to the pronator teres, and the 

 apex to the meeting of these muscles. The tendon of the biceps can be easily made out in the 

 centre of the fossa, giving off above the lacertus fibrosus from its medial side to fasten down the 

 flexors of the forearm. Under the tendon on its medial side lie the brachial artery and the 

 median nerve, a little medial to it, for a short distance. The radial nerve (musculo-spiral) lies 

 •outside the fossa, between the brachio-radialis and the brachialis (anterior), and gives off its two 



Fig. 1136. — The Bend op the Elbow with the Superficial Veins. 

 (From a dissection by Dr. Alder Smith in the Museum of St. Bartholomew's Hospital.) 



Median nerve 

 Posterior branch of in- 

 ferior ulnar collateral 

 Branches of medial | 

 anti-brachial , 

 cutaneous nerve [ 



Posterior ulnar vein 



Brachialis 

 Anterior branch of in- 

 ferior ulnar collateral 

 Anterior ulnar vein 

 Median basilic vein 



Muscular branch of 

 median nerve 



Tendon of biceps 

 Lacertus fibrosus 



Brachialis 



Deep median vein 

 Ulnar artery 



Pronator teres 



Radial artery 



Biceps 



Vena comitans of 



brachial artery 

 Basilic vein 



— Brachialis 



Cephalic vein 

 Brachial artery 

 Lateral anti- 

 brachial cuta- 

 neous nerve 

 Radial n. and as- 

 cending branch 

 of radial recur- 

 rent artery 

 Radial vein 

 Median cephalic 



vein 

 Ascending br. of 

 radial recurrent 

 Superficial radial 



nerve 



Radial recurrent 



artery 



Brachio-radialis 



Descending br. of 

 radial recurrent 



Median vein 



Superficial 

 radial 

 nerve 



terminal branches in front of the lateral epicondyle. The brachial usually bifurcates oppo- 

 site to the neck of the radius. 



The arterial anastomoses about the elbow-joint are as follows: The radial recurrent runs up 

 under cover of the bracliio-radialis to aiiastoinose with the anterior branch of the profunda 

 on the front of the lateral condyle. The posterior interosseous recurrent ascends, between the 

 HU[)iiiat(»r and tlie anc(jiicus, to anastomo.se on the back of the lateral condyle with the posterior 

 branch of the profunda. It further joins, by a large anastomotic arch across the back of the 

 joint, with tbe inferior ulnar collateral (anasfoinolic niagn.a) and posterior ulnar recurrent. 

 The anterior ulnar recurrent passes upward on the brachialis to join the anterior part of the 

 inferior ulnar collateral under the pronator tores, on the front of iho medial epicondyle. The 

 posterior ulnar recurrent makes for the interval between the back of the medial epicondyle 

 and the olecranon, to join with the superior and the posterior branch of the inferior ulnar 

 collateral. 



It will be .seen that the inferior ulnar collateral (anastomotica magna) is the artery most 

 largely employed, distributing branches everywhere, save to the front of the lateral epicondyle. 



