27 



blood to the surrounding tissues. The posterior radial is a con- 

 tinuation of the humeral artery, passing down the inner side of 

 the foreleg with a vein and nerve of the same name, inclining 

 backward and dividing at the lower end of the radius into large 

 and small metacarpals. 



The large metacarpal artery is a continuation of the posterior 

 radial. It runs down the back of the knee in company with the 

 flexor tendons and the internal metacarpal vein and nerve; above 

 the fetlock it passes between the tendons and suspensory hga- 

 ment, di%iding into the external and internal digital arteries. 



The small metacarpal artery passes outward from the inner 

 and back part of the knee, and running downward joins another 

 artery suppl™g nourishment to the surrounding tissues. 



Circulation of the hind leg.— The femoral artery is the artery 

 of the thigh. Just above the back of the stifle joint it becomes 

 the popliteal artery, which divides into two mam branches, the 

 anterior and posterior tibial, the latter supphing the posterior 

 part of the ga^kin and hock with nourishment, while the former 

 winds forward between the tibia and fibula to the fore part of 

 the leg, gaining it midway between the stifle and the hock. At 

 the hock it passes obliquely outward, crossing the joint, and 

 becomes the great metatarsal artery at the upper and external 

 part of the metatarsus; it then passes under the small splint bone 

 and gains the back part of the cannon, and then, passing down 

 the leg, it divides just below the bifurcation of the suspensory 

 ligament into two branches, the external and internal digitals. 



■ The digital arteries, which are alike in the fore and hind limbs, 

 originate at an acute angle just below the middle of the cannon 

 bone in front of the flexor tendons, passing over the inner and 

 outer side and accompanied by corresponding veins and nerves 

 of the same names, the artery being central and the nerve poste- 

 rior. Each runs down the side of the foot . inside the lateral carti- 

 leges, to the superior border of the wings of the os pedis, thence 

 they reach the middle and under surface of the bone at either 

 side of the flexor pedis jyerforans tendon. They supply numer- 

 ous twigs to the flexor and extensor tendons, fetlock pad and 

 joint, and give off the following branches, which are usually re- 

 garded as the arteries of the foot: They are five in number, jjer- 

 pendicular, transverse, artery of the frog, prepJantar inignal, and 

 plantar ungual. The arteries ramify through the foot, supplying 

 it with nutrition. 



