ULNAR ARTERY. DIGITAL ARTERIES. 277 



The Ulnar Artery. 



The Ulnar artery proceeds among the muscles obliquely 

 downwards guided as it were by the flexor ulnaris, and is not 

 superficial until it has arrived within three or four inches of 

 the carpus : it then continues towards the hand, sending off 

 very small branches in its progress. It passes over the annular 

 ligament at the wrist, and winds round the pisiform bone: 

 here it is supported by a delicate ligament, which seems to lie 

 upon it : from this it passes upon the palm of the hand, under 

 the aponeurosis palmaris, and over the tendons of the flexors 

 of the fingers. When thus situated, it forms, in perhaps a 

 majority of subjects, an arch or bow, called Arcus Sublimis, 

 which extends across the palm of the hand, from the ulnar 

 towards the radial edge, and, after sending branches to the 

 fingers, from its convex side, terminates near the root of 

 the thumb, by anastomoses with that important branch of the 

 radial artery, {super Jicia lis volae) which passes up on the inside 

 of the thumb. The Arcus Sublimis almost always sends off 

 small branches, to the integuments, &c., on the palm of the 

 hand. It sends off, near the root of the metacarpal bone of 

 the little finger, a branch which passes between the flexor ten- 

 dons and the metacarpal bones, and anastomoses with the Arcus 

 Profundus. It then generally sends off a branch to the inner 

 or ulnar side of the little finger ; and afterwards three branches 

 in succession, which pass from its convex side towards the 

 angles formed by the fingers. These are called 



The Digital Arteries. 



When they have arrived near to the heads of the first pha- 

 langes of the fingers, each of these arteries divides into two 

 branches, one of which passes along the side of one of the fin- 

 gers to its extremity, and the other on the opposite side of the 

 next finger : and in this way they pass on the sides of all the 

 fingers, except the inside of the little finger, and the outside of 

 the index which are supplied from the radial artery. 



These branches of the digital arteries are called Digiio-Radial 

 VOL. II. 24 



