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THE COMMON DIGITAL ARTERY—THE DIGITAL ARTERIES 659 
THE COMMON DIGITAL ARTERY 
The common digital artery (A. digitalis communis s. metacarpea volaris 
superficialis)' is the direct continuation of the median. It descends in the 
carpal canal along the medial side of the flexor tendons in company with the 
medial volar nerve. Continuing down the limb it preserves this relation to the 
tendons to the distal third of the metacarpus, where it inclines toward the middle 
line of the limb behind the suspensory ligament, and divides into the medial and 
lateral digital arteries. In the metacarpus the artery is related to the vein in front 
and the nerve behind, and is covered by the fascia and skin. It furnishes collateral 
branches to the suspensory ligament, the flexor tendons, and the skin. 
THE DIGITAL ARTERIES 
The digital arteries, medial and lateral (A. digitalis volaris propria medialis, 
lateralis), are formed by the bifurcation of the common digital at the distal third 
of the metacarpus. They diverge, pass down over the abaxial surface of the cor- 
responding sesamoid at the fetlock, and descend parallel with the borders of the deep 
flexor tendon to the volar grooves and foramina of the third phalanx. Entering the 
latter the two arteries unite in the semilunar canal and form the terminal arch 
(Arcus terminalis), from which numerous branches pass through the bone to the 
dorsal surface and ramify in the corium of the wall and sole of the hoof.2. A num- 
ber of branches emerge through the foramina at the distal border, where they anas- 
tomose with each other in arciform fashion. 
These branches were named by Spooner the inferior communicating arteries, and the anas- 
tomotie arch formed by them is termed the circumflex artery of the third phalanx (Chauveau) 
or the artery of the distal border of the third phalanx (Leisering). 
Each artery is accompanied by a vein and by the digital nerves. Above the 
fetlock the artery is most deeply placed and is covered by the vein; the nerve is 
beh nd the vein. At the fetlock the artery has become superficial and is related 
to the vein in front and the posterior branch of the nerve behind. The anterior 
branch of the nerve crosses over the artery obliquely to the side of the first phalanx. 
The artery and nerves are crossed obliquely by a small band, the tendon or ligament 
of the ergot (vide digital fascia). 
In addition to branches to the joints, tendons and synovial sheath, ergot, and 
skin, the digital arteries give off the following named branches: 
1. The artery of the first phalanx (A. phalangis prime)? is a short trunk which 
arises at a right angle about the middle of the first phalanx, and divides into 
dorsal and volar branches. The dorsal branch (Ramus dorsalis) passes between 
the first phalanx and the extensor tendon and ramifies on the front of the digit, 
anastomosing with its fellow. The volar branch (Ramus volaris) dips in between 
the flexor tendons and the first phalanx and anastomoses with the opposite artery 
between the superficial and middle distal sesamoidean ligaments. 
2. The artery of the digital cushion (A. toric phalangis tertiz) arises at the 
proximal border of the cartilage of the third phalanx and passes backward and 
downward to ramify in the digital cushion and the corium of the heels and frog. 
3. The dorsal artery of the second phalanx (Ramus dorsalis phalangis secund:e) 
arises a little above the level of the distal sesamoid bone, and passes forward under 
cover of the cartilage of the third phalanx and the extensor tendon to the front of 
the second phalanx, where it anastomoses with the opposite vessel. It gives 
1 This vessel is also termed the large or palmar metacarpal artery. 
* The terminal part of the digital artery has been termed the plantar artery. 
8’ Also termed the perpendicular artery. 
