ULNAE ARTERY. RECURRENT BRANCHES. 389 



the superficial muscles arising from the inner condyle of the humerus, 

 viz., the pronator teres, flexor carpi radialis, palmaris longus, and flexor 

 sublhnis, until it reaches the flexor carpi ulnaris near the junction of the 

 upper with the middle third of the fore-arm ; at this point the artery comes 

 into contact with the ulnar nerve, which was previously separated from it by 

 a considerable interval, and changing its direction, descends vertically with 

 the nerve towards the inner border of the palm of the hand. Descending 

 along the radial border of the tendon of the flexor ulnaris muscle, the 

 ulnar artery reaches the outer or radial side of the pisiform bone, where, 

 still accompanied by the nerve, it passes over the cutaneous surface of the 

 anterior annular ligament of the wrist into the palm of the hand. Its 

 disposition in the hand will be separately described. 



In the first half of its course through the fore-arm, the artery is deep- 

 seated, being covered by the muscles arising from the inner condyle of the 

 humerus which have been already enumerated. About the middle of the 

 fore- arm it is overlapped by the fleshy part of the flexor carpi uluaris ; but 

 below that, it becomes more superficial, being overlaid by the tendon of the 

 muscle, and covered by the skin, the fascia of the fore-arm, and a thin layer 

 of membrane by which the vessel is bound down to the muscle beneath. At 

 first the ulnar artery lies on the insertion of the brachialis anticus into the 

 coronoid process of the ulna; then on the flexor profuudus in the rest of 

 the fore-arm, and lastly, on the annular ligament of the carpus. Below the 

 point at which it emerges from under the flexor carpi ulnaris (or a little 

 below the middle of the fore-arm), the tendon of that muscle is on its inner 

 or uluar side. 



Relation to Nerves. The median nerve lies immediately on the inner side 

 of the ulnar artery at its origin, but being directed down the middle of the 

 fore-arm it soon passes over the vessel, separated from it at the point of 

 crossing by the deep head of the pronator teres muscle. As the ulnar 

 nerve descends behind the inner condyle of the humerus, it is removed from 

 the ulnar artery by a considerable interval at the upper part of the fore- arm ; 

 but as the vessel inclines inwards, it approaches the nerve, and is accom- 

 panied by it in the lower half of its course the nerve lying close to its 

 inner side. A small branch of the uluar nerve descends upon the lower 

 part of the vessel. 



Relation to Veins. Two veins (venae comites) accompany the uluar 

 artery, and are frequently united by branches crossing it. 



BRANCHES. The ulnar artery gives off" in the fore-arm the anterior and 

 posterior recurrent, the iuterosseous, and several muscular branches. At 

 the wrist it gives off the anterior and posterior carpal branches. 



RECURRENT BRANCHES. The anterior ulnar recurrent artery, a small 

 branch, arches inwards and upwards from the upper part of the ulnar artery, 

 running on the brachialis anticus muscle, and covered by the pronator teres, 

 both which muscles it partly supplies. On reaching the front of the inner 

 condyle, it anastomoses with the inferior profunda and anastomotic arteries, 

 derived from the brachial. 



The posterior ulnar recurrent, larger than the preceding, comes off lower 

 down ; but not unfrequently the two vessels arise by a short common trunk. 

 The posterior recurrent runs inwards and backwards beneath the flexor sub- 

 limis, and then ascends behind the inner condyle. In the interval between 

 that process and the olecranon it lies beneath the flexor carpi ulnaris, and 

 passing between the heads of that muscle along the ulnar nerve, supplies 

 branches to the muscles, to the elbow-joint, and to the nerve itself. This 



