414 ARTERIES. 



carpi ulnaris and Flexor sublimis digitorum muscles. It is accompanied by two 

 veins, which lie one on each side of the vessel ; the ulnar nerve lies on its inner 

 side for the lower two-thirds of its extent, and a small branch from it descends on 

 the lower part of the vessel to the palrn of the hand. 



PLAN OF RELATIONS OF THE ULNAE AETEKY IN THE 



In front. 



Superficial and deep fascice. Lower half of the artery. 



Inner side. / \ Outer side. 



Flexor carpi ulnaris. ( uinar ) Flexor sublimis digitorum. 



Ulnar nerve (lower two-thirds of 

 the artery.) 



Behind. 



Brachialis anticus. 

 Flexor profundus digitorum. 



At the wrist, the ulnar artery is covered by the integument and fascia, and lies 

 upon the anterior annular ligament. On its inner side is the pisiform bone. The 

 ulnar nerve lies at the inner side, and somewhat behind the artery. 



In the palm of the hand, the continuation of the ulnar artery is called the super- 

 ficial palmar arch ; it passes obliquely outwards to the interspace between the 

 ball of the thumb and the index-finger, where it anastomoses with the superficial 

 volae, and a branch from the radialis indicis, thus completing the superficial pal- 

 mar arch. The convexity of this arch is directed towards the fingers, its concav- 

 ity towards the muscles of the thumb. 



The superficial palmar arch is covered by the Palmaris brevis, the palmar fascia, 

 and integument ; and lies upon the annular ligament, the muscles of the little finger, 

 the tendons of the superficial Flexor, and the divisions of the median and ulnar 

 nerves, the latter accompanying the artery a short part of its course. 



RELATIONS OF THE SUPERFICIAL PALMAE ARCH. 



In front. /^ "\ Behind. 



Integument. ( uinar \ Annular ligament. 



Palmaris brevis. A ^7 d m Ongm of muscles of little finger. 



Pnlmar fWia V / Superficial Flexor tendons. 



XulUlar IdbCld. \ / _-. . r . . n T 11 



\. / Divisions of median and ulnar nerves. 



Peculiarities. The ulnar artery was found to vary in its origin nearly in the proportion of 

 one in thirteen cases, in one case arising lower than usual, about two or three inches below the 

 elbow, and in all the other cases much higher, the brachial being a more frequent source of origin 

 than the axillary. 



Variations in the position of this vessel are more frequent than in the radial. When its ori- 

 gin is normal, the course of the vessel is rarely changed. When it arises high up, its position 

 ID the forearm is almost invariably superficial to the Flexor muscles, lying commonly beneath the 

 fascia, more rarely between the fascia and integument. In a few cases, its position was subcu- 

 taneous in the upper part of the forearm, sub-aponeurotic in the lower part. 



Surgical Anatomy. The application of a ligature to this vessel is required in cases of wound 

 of the artery, or of 'its branches, or in consequence of aneurism. In the upper half of the fore- 

 arm, the artery is deeply seated beneath the superficial Flexor muscles, and their division would 

 be requisite in a case of recent wound of the artery in this situation, in order to secure it, but 

 under no other circumstances. In the middle and lower third of the forearm, this vessel may be 

 easily secured by making an incision on the radial side of the tendon of the Flexor carpi ulnaris ; 

 the deep fascia being divided, and the Flexor carpi ulnaris and its companion muscle, the Flexor 

 sublimis, being separated from each other, the vessel will be exposed, accompanied by its venae 

 comites, the ulnar nerve lying on its inner side. The veins being separated from the artery, the 

 ligature should be passed from the ulnar to the radial side, taking care to avoid the ulnar nerve. 



