ULXAR 533 



which the uhiar is given off. At times it runs beneath tlie muscles, or merely beneath the skin. 

 (B) It may in some cases of high division of the brachial run beneath the fascia throughout its 

 whole extent in the forearm. (C) In some cases of normal origin from the brachial it takes a 

 .superficial course in the forearm, being merely covered by the fa.scia, the recurrent branches and 

 the common interosseous then arising from the radial. 



The branches of the ulnar artery in the forearm are: — 1. The anterior 

 uhiar recurrent. 2. The posterior uhiar recurrent. 3. The interosseous, or com- 

 mon interosseous: (a) anterior interosseous — (i) arteria conies nervi mediani, (ii) 

 muscular, (iii) medullary, (iv) anterior communicating; (6) posterior interosse- 

 ous — (i) interosseous recurrent, (ii) muscular, (iii) articular. 4. Muscular. 5. 

 Nutrient. 6. Posterior ulnar carjnil. 7. Anterior ulnar carpal. 



1 . The anterior ulnar recurrent is a small branch which leaves the inner side 

 of the ulnar artery soon alter its origin, and, running upwards and inwards between 

 the outer edge of the pronator teres and the brachialis anticus, anastomoses in 

 front of the internal condyle with the anastomotica magna and a branch of the 

 inferior ])rofunda artery. It supplies branches to the muscles between which it 

 runs. 



2. The posterior ulnar recurrent, larger than the anterior ulnar recurrent, 

 comes off from the inner side of the ulnar artery, either a little below the latter 

 branch, or else as a common trunk with it, and, passing inwards between the flexor 

 sublimis and flexor profundus digitorum, turns upwards to the back of the internal 

 condyle, where it lies with the ulnar nerve l)etween the two heads of origin of the 

 flexor carpi ulnaris. It supplies the contiguous muscles — the flexor carpi ulnaris. 

 the palmaris longus, and the flexor sublimis and profundus digitorum — the elbow- 

 joint and the ulnar nerve, and anastomoses with the inferior profunda, Avith the 

 anastomotica magna, and Avith the interosseous recurrent, forming the so-called rete 

 olecrani. 



3. The interosseous or common interosseous artery, is a short thick trunk 

 half an inch or so in length. Avhich comes oft" from the outer and back part of the 

 ulnar artery aljout an inch from its origin, and just before that artery is crossed by 

 the median nerve. It passes backwards and downwards between the flexor longus 

 pollicis and the flexor profundus digitorum, tOAvards the triangular interval 

 bounded by the upper border of the interosseous membrane, the oblique ligament, 

 and the outer border of the ulna. Avhere it divides into the anterior and posterior 

 interosseous arteries. 



(a) The anterior interosseous artery, smaller than the posterior, but appar- 

 ently the direct continuation of the c(jmmon trunk, courses cloAvnAvards in front of the 

 interosseous membrane, upon Avhich it lies under cover of the overlapping edges of 

 the flexor profundus digitorum and flexor longus pollicis, to the upper border of the 

 pronator (juadratus, Avhere it terminates in two branches, an anterior terminal and 

 a posterior terminal. 



The anterior interosseous artery is accompanied by two veins and by the deep 

 branch of the median nerve Avhich lies to its radial side. The artery is bound down 

 to the inter(.)sseous membrane l)y ajioneurotic fibres. 



The branches of the anterior interosseous artery are: — (1) The arteria 

 comes nervi mediani — or the median artery as it is sometimes shortly called — is 

 a long slender vessel, Avhich arises from the anterior interosseous immediately after 

 the latter is given oft' from the common trunk. It ]iasses forAvards betAveen the 

 flexor profundus digitorum and the flexor longus pollicis to the median nerA'e, Avith 

 AA'hich it descends beneath the amiular ligament into the palm, and Avhen of large 

 size sometimes enters into the formation of the superficial palmar arch. At times 

 the artery arises from the connnon interosseous before its division, (h) Muscular 

 branches supply the flexor longus pollicis, flexor profundus digitorum, and pro- 

 nator quadratus, and the extensor muscles of the thumb, which they reach by 

 passing baclcAvards through the interosseous membrane, (iii) The nutrient 

 arteries of the radius and ulna are usualh' deriA-ed from this vessel, (iv) The 

 anterior terminal and smaller division of the anterior interosseous artery, some- 

 times called tlie anterior coimnunicating, passes either in front of or behind the 

 pronator quadratus, but in either case in front of the interosseous membrane, and 

 anastomoses with the anterior carpal branches of the radial and ulnar arteries, and 



