THE ARTERIES OF THE UPPER LIMB. 



the superior prof unda branch forms the principal channel through which the circulation is 

 carried on, by means of its anastomoses with the radial recurrent, interosseous recurrent, and 

 anastomotic arteries. If the ligature has been placed on the artery near the elbow, the 

 inferior profunda and anastomotic arteries will assist by their communications with the ulnar 

 recurrents. 



ULNAR ARTERY (III). 



The ulnar artery, the larger of the two vessels into which the brachial divides, 

 extends along the inner side of the forearm into the palm of the hand, where it 

 forms the superficial palmar arch. In this course it inclines at first downwards and 

 inwards, describing a slight curve the convexity of which is directed inwards, and 

 passes between the superficial and deep layers of muscles ; somewhat above the 

 middle of the forearm the artery comes into contact with the ulnar nerve, which 

 was previously separated from it by a considerable interval, and thence descends 

 vertically with the nerve towards the inner border of the palm of the hand. Lying 

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

 artery reaches the outer side of the pisiform bone, where, still accompanied by the 

 nerve, it passes over 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 forearm, the artery is deeply seated, 

 being covered by the muscles arising from the inner condyle of the humerus, viz., 

 pronator teres, flexor carpi radialis, palmaris longus, and flexor sublimis digitorum. 

 From the middle of the forearm it is overlapped by the flexor carpi ulnaris till 

 within an inch of the wrist, where it lies immediately under the fascia. Beneath 

 the tendon of the flexor carpi ulnaris the artery is also covered by a thin layer of 

 membrane by which it is bound down to the muscle beneath. At first the ulnar 

 artery lies on the insertion of the brachialis anticus, then on the flexor profundus 

 digitorum in the rest of the forearm, and lastly on the annular ligament of the 

 wrist. Below the point at which it emerges from under the flexor carpi ulnaris, the 

 tendon of that muscle is on its inner or ulnar side. 



Relation to veins. The ulnar artery is accompanied by two veins (vencc, comites), 

 which are united by numerous cross branches. 



Relation to nerves. The median nerve lies at first immediately on the inner side 

 of the ulnar artery, but being directed down the middle of the forearm 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 separated from the ulnar arteiy by a considerable 

 interval at the upper part of the forearm ; but as the vessel inclines inwards, 

 it approaches the nerve, and is accompanied by it in the lower half or more of its 

 course the nerve lying close to its inner side. The small palmar cutaneous branch 

 of the ulnar nerve descends upon the lower part of the artery. 



BEANCHES. The ulnar artery in the forearm gives numerous muscular 

 branches, of small size, to the surrounding muscles, and the following named 

 offsets, viz. : 



1. The anterior ulnar recurrent artery, a small branch, arches inwards and 

 upwards from the upper part of the ulnar artery, in front of the inner condyle, 

 lying on the brachialis anticus, and covered by the pronator teres, both of which 

 muscles it partly supplies. It ends by communicating with the anastomotic branch 

 of the brachial. 



2. The posterior ulnar recurrent artery, larger than the preceding, comes 

 off a little lower down ; but not unfrequently the two vessels arise by a short 

 common trunk. The posterior recurrent runs inwards and backwards beneath the 

 flexor sublimis, and then, ascends behind the inner condyle. In the interval 



