_a_, Brachial; _a′_, median; _c_, common interosseous; _d_, volar
antibrachial; _e_, radial; _e′_, _e″_, dorsal and volar branches of
_e_; _f_, _f′_, cutaneous branches of _e_; _g_, ulnar; _1_, biceps
brachii; _2_, extensor carpi radialis; _3_, pronator teres; _4_,
deep digital flexor; _5_, radius; _6_, superficial digital flexor;
_7_, flexor carpi radialis; _8_, flexor carpi medius; _9_, humerus.
(Ellenberger-Baum, Anat. d. Hundes.)
]
The =ulnar artery= descends on the deep flexor of the digit, and sends a
connecting branch to the radial above the carpus. Near the middle of the
metacarpus it gives off the =first volar metacarpal artery= and divides
into the =second=, =third=, and =fourth superficial volar metacarpal
arteries=. The first volar artery unites with the corresponding dorsal
artery to form the =first common digital artery=, which supplies proper
digital arteries for the opposed surfaces of the first and second
digits. The superficial volar arteries descend in the spaces between the
other metacarpal bones, unite near the metacarpo-phalangeal joints with
the corresponding deep volar and dorsal metacarpal arteries to form
three =common digital arteries=. Each of the latter divides after a
short course into two =proper digital arteries=, which run along the
opposed surfaces of the second to the fifth digits. The external digital
artery of the fifth digit comes from the =superficial volar arch= formed
by the union of a branch of the volar interosseous with the fourth
superficial volar metacarpal artery.
[Illustration:
FIG. 489.—ARTERIES OF DISTAL PART OF RIGHT FORE LIMB OF DOG, ANTERIOR
VIEW.
_a_, Branch of volar interosseous artery; _b_, proximal collateral
radial artery (external branch); _c_, radial artery (dorsal branch);
_d_, rete carpi dorsale; _e_, deep dorsal metacarpal arteries; _f_,
superficial dorsal metacarpal arteries; _g_, common digital
arteries; _h_, proper digital arteries.
]
[Illustration: