658 BLOOD-VASCULAR SYSTEM OF THE HORSE 
given off from the median at an acute angle, usually a little above the lateral 
one or by a common trunk with it. It passes down the medial side of the carpus 
behind the tendon of the flexor carpi radialis and embedded in the posterior annular 
ligament. Arriving at the proximal end of the medial metacarpal bone it becomes 
more deeply placed and is connected with the lateral volar artery by one or two 
transverse branches, as stated above. It then pursues a flexuous course downward 
Lateral metacarpal vein 
Medial metacarpal vein 
Medial ligament of carpus Posterior annular ligament of 
. , 245 carpus 
Tendon of extensor carpr radialis 
Tendon of extensor carpi obliquus 
Superficial flexor tendon 
Medial volar nerve 
Communicating branch 
Common digital artery 
Medial metacarpal vein 
Suspensory ligament 
Lumbricalis muscle 
Medial ligament of fetlock joint Dorsal digital nerve 
Common extensor tendon Volar digital nerve 
Extensor branch of suspensory Digital artery 
ligament ; ‘ 
Digital vein 
Dorsal artery of first phalanx Tigament operas 
Deep flexor tendon 
Cartilage of third phalanx 
Medial ligament of pastern joint 
Coronary plexus 
Coronary corium 
Laminar corium 
Fic. 572.—Dissection oF Ricut Carpus, Meracarpus, AND Dicirt or Horse; Meptar View. (After Schmaltz, Atlas 
d. Anat. d. Pferdes.) 
alongside of the medial small metacarpal bone, like the corresponding lateral 
artery, with which it commonly unites as described above. It is larger than the 
lateral artery, and supplies the nutrient artery to the large metacarpal bone. 
The foregoing account describes the most common arrangement of the dorsal and volar 
metacarpal arteries. Variations in. their origin and connections are common, but have no great 
surgical importance. Collateral branches are omitted for the same reason. In some cases the 
medial volar metacarpal is connected with the common digital artery a little below the carpus by 
a branch passing obliquely across the medial border of the deep flexor tendon; this forms a super- 
ficial volar arch. 
