ourse
lie parallel to each other; both are comparatively superficial, but of
the two, the radial artery is the more superficial and isolated, and
thereby occasions the radial pulse. The anatomical situation of the
radial artery accounts for the fact, why the pulsation of this vessel is
more easily felt than that of the ulnar artery.

The radial vessel, A, Plate 17, at the wrist, is not accompanied by the
radial nerve; for this nerve, C, Plate 19, passes from the side of the
artery, at a position, C, Plate 19, varying from one to two or more
inches above the wrist, to gain the dorsal aspect of the hand. The ulnar
artery, C, Plate 17, is attended by the ulnar nerve, D, in the wrist,
and both these pass in company to the palm. The ulnar nerve, D E, lies
on the ulnar border of the artery, and both are in general to be found
ranging along the radial side of the tendon of the flexor carpi ulnaris
muscle, T, and the pisiform bone, G. The situation of the radial artery
is midway between the flexor carpi radialis tendon, I, and the outer
border of the radius. The deep veins, called comites, lie in close
connexion with the radial and ulnar arteries. When it is required to lay
bare the radial or ulnar artery, at the wrist, it will be sufficient for
that object to make a simple longitudinal incision (an inch or two in
length) over the course of the vessel A or C, Plate 17, through the
integument, and this incision will expose the fascia, which forms a
common investment for all the structures at this region. When this
fascia has been cautiously slit open on the director, the vessels will
come into view. The ulnar artery, however, lies somewhat concealed
between the adjacent muscles, and in order to bring this vessel fully
into view, it will be necessary to draw aside the tendon of the flexor
ulnaris muscle, T.

The radial artery, A, Plate 18, passes external to the radial border of
the wrist, beneath the extensor tendons, B, of the thumb; and after
winding round the head of the metacarpal bone of the thumb, as seen at
E, Plate 19, forms the deep palmar arch E, Plate 18. This deep palmar
arch lies close upon the forepart of the carpo-metacarpal joints; it
sends off branches to supply the deeply situated muscles, and other
structures of the palm; and from it are also derived other branches,
which pierce the interosseal spaces, and appear on the back of the hand,
Plate 19. The deep palmar arch, E, Plate 18, inosculates with a branch