THE ULXAR ARTERY. 71 



deep ligament connecting together the heads of the metacarpal 

 bones, and to the edge of the metacarpal bone for a short distance. 



The superficial transverse ligament of the fingers is a thin fibrous Transverse 

 band, which stretches across the roots of the four fingers, and is 

 contained in the fold of skin, forming the rudiment of a web 

 between them. Beneath it the digital nerves and vessels are con- 

 tinued onwards to their terminations. 



Sheath of the flexor tendons. Along each finger the flexor tendons Sheath of 

 are retained in place against the phalanges by a fibrous sheath. the tendons 

 Opposite the middle of the first and second phalanges the sheath is varies in 

 strengthened by a strong fibrous band (vaginal ligament), which is thickness ; 

 almost tendinous in consistence, but opposite the joints it consists 

 of a thin membrane with scattered and oblique fibres. The has a syno- 

 sheath will be opened later on in the examination of the flexor V1 ' 

 tendons. 



Dissection. The palmar fascia should next be taken away. On Dissection, 

 the removal of the fascia the palmar arch of the ulnar artery and 

 the median and ulnar nerves become apparent. 



PALMAR PART OF THE TANAR ARTERY (fig. 28). In the palni of superficial 

 the hand the ulnar artery divides into two branches, superficial palp^r 

 and deep. The larger superficial branch is directed towards the 

 muscles of the thumb, where it communicates with two offsets of 

 the radial trunk, viz., the superficial volar branch (c) and the 

 branch to the radial side of the forefinger (/). The curved part 

 of the artery, which lies across the hand, is named the superficial 

 palmar arch (d). Its convexity is turned towards the fingers, and position in 

 its position in the palm would be nearly marked by a line across tbe hand ; 

 the hand from the cleft of the thumb. 



The arch is comparatively superficial, being covered for the most relations, 

 part only by the integuments and the palmar fascia ; but at the 

 inner border of the hand the palmaris brevis muscle (H) lies over it. 

 Beneath it are the flexor tendons and the branches of the ulnar and 

 median nerves. Venge comites lie on its sides. 



The deep or communicating branch of the ulnar artery (fig. 3 1 2 , Deep 

 p. 77) passes backwards with the deep part of the ulnar nerve, branch 5 

 between the abductor and short flexor muscles of the little 

 finger, to inosculate with the deep palmar arch of the radial artery 

 (p. 80). 



Branches. From the convexity of the superficial arch proceed 

 the digital arteries, and from the concavity some small offsets to 

 the palm of the hand. 



The digital branches (g) are four in number, and supply both four digital 

 sides of the three inner fingers and one side of the index finger. branches: 

 The branch to the inner side of the hand and little finger is un- 

 divided ; but the others, lying over the three inner interosseous 

 spaces, bifurcate below to supply the contiguous sides of the corre- 

 sponding digits. In the palm these branches are accompanied by 

 the digital nerves, which they sometimes pierce. 



Near the roots of the fingers they receive communicating branches these join 

 from onsets of the deep arch ; but the digital artery of the inner 



