3/0 A MANUAL OF ANATOMY 



The internal or hypothenar division, also thin, is connected 

 above with the anterior annular ligament, and terminates below 

 over the muscles inserted into the inner side of the base of the first 

 phalanx of the little finger. 



Third Part of the Ulnar Artery. — ^The third part of the vessel forms 

 the superficial palmar arch. It descends for a little under cover of 

 the palmaris brevis, and then turns outwards across the palm in an 

 arched manner. About the middle of the thenar eminence it is 

 joined by the superficial volar of the radial, or by a branch of the 

 arteria radialis indicis, or, failing these, by a branch of the arteria 

 princeps pollicis, and so the arch is completed externally. Its con- 

 vexity is directed towards the fingers, and its course may be indicated 

 by a line drawn across the palm from the web between the thumb 

 and index finger (the thumb being abducted) to the outer side of the 

 pisiform bone, the line being slightly arched, with the convexity 

 towards the fingers. 



Relations — Stiperfidal. — The integument, the palmaris brevis for 

 a short distance internally, and the central division of the palmar 

 fascia. Deep. — From within outwards it rests upon the opponens 

 minimi digiti, the digital branches of the ulnar nerve, the flexor, 

 tendons, and the digital branches of the median nerve. The arch, 

 lies within the great palmar bursa. 



Branches. — The branches of the arch are cutaneous to the integu- 

 ment of the. palm, muscular to the adjacent superficial muscles, thej 

 profunda branch, and the digital branches. 



The profunda artery is given off from the commencement of theT 

 arch, opposite the lower border of the anterior annular ligament. 

 It at once passes deeply, in company with the deep division of the 

 ulnar nerve, between the abductor and flexor brevis minimi digiti, 

 then through the opponens minimi digiti, and it terminates by 

 anastomosing with the third part of the radial artery, thereby 

 completing the deep palmar arch. In its short course it gives 

 branches to the hypothenar muscles. 



The digital arteries arise from the convexity of the arch, and are 

 four in number. They are destined for the sides of the inner three 

 and a half fingers, and are called first, second, third, and fourth, 

 from within outwards. The first is a single arteiy, but the other 

 three are compound, each ultimately dividing into two. The first 

 digital artery, of small size, passes downwards and inwards over 

 the hypothenar muscles, to which it gives twigs, and then it passes 

 along the inner side of the little finger. 



The second, third, and fourth digital arteries, which are compound, 

 pass downwards over the fourth, third, and second interosseous 

 spaces to near the clefts between the little and ring, ring and middle, 

 and middle and index fingers, where each divides into two collateral 

 digital arteries, which pass along the contiguous sides of these fingeffl. 

 These four digital arteries account for the blood-supply of the sides 

 of the inner three and a half fingers. The outer side of the indfflc 

 finger and both sides of the thumb are supplied by the arteria j 



