270 OUTLINES OF EQUINE ANATOMY. 



up to become inserted into several of the small bones of 

 that joint, while the tendons of the muscular portion pass 

 between its divisions, thus completing its inferior attach- 

 ment to all the small bones of the hock, directly or indi- 

 rectly, and to the upper part of the three metatarsal bones. 

 With one of these tendons the middle band of the anterior 

 annular ligament of the hock blends. 



Extensor pedis, arising from the originating portion of 

 the tendinous part of flexor metatarsi, as above indicated, 

 passes down the front of the hock, and through its three 

 anterior annular ligaments, lubricated by synovia. After 

 receiving the tendons of peroneus and extensor pedis 

 accessorius opposite the inferior part of the superior third 

 of OS metatarsi magnum, it comports itself as does the 

 extensor pedis of the fore limb. 



Extensor pedis accessorius arises from the front of 

 astragalus below its articular ridges, and joins extensor 

 pedis, which covers it from its origin, bein g slightly visible 

 between it and peroneus. 



The terminal portion of the femoral artery passes 

 between the two heads of gastrocnemius externus, and 

 then between its internal head and the head of ga.strocne- 

 mius iuternus. It sends off a hrancJi ichich runs doiunwards 

 behveen the huo gastrocnemii, and then passes between the 

 condyles of the femur to break up behind the stifle-joint, 

 forming the anterior and the posterior tibial arteries. 



The posterior tibial artery runs down the posterior sur- 

 face of the tibia, at first between popliteus and the bone, 

 subsequently between flexores pedis j)erforans and acces- 

 sorius. It becomes superficial at the supero -internal part 

 of the hock, and here makes its sigmoid flexure, by which, 

 in terminating, it anastomoses superiorly with the arterial 

 branch between the gastrocnemii, inferiorly with the recur- 

 rent branch of the metatarsal artery. It supplies the 

 muscles and skin at the posterior part of the tibia, and 

 the medullary artery of that bone at the inferior part of 

 its superior third. 



The anterior tibial artery runs in a forward direction 

 from its origin, and passes between the tibia and the fibula, 

 and thus underneath jDeroneus to gain the front of the 

 limb, down which it passes underneath flexor metatarsi 

 and extensor pedis, which it supplies. At the front of the 

 hock it passes through an oblique groove at the outer 



