416 ANGIOLOGY. 



tion of the perforating artery, running down the inner border of 

 the suspensory ligament ; the external one, very small, passes 

 down the outer -border. At the fetlock joint these vessels 

 unite with the great metatarsal artery to form the sesamoidean 

 arch. 



ANTERIOR TIBIAL ARTERY. 



(FiG. 160. 3, 3.) 



This is part of the main trunk, being really the continuation 

 of the popliteal ; it winds forwards between the tibia and fibula 

 to the fore part of the leg, gaining it midway between the stifle 

 and hock. It lies between the deep face of the flexor metatarsi 

 muscle and the tibia. At the hock it passes obliquely outwards, 

 crossing the joint, and becomes the great metatarsal artery at 

 the proximal end of the metatarsus. It gives off twigs to the 

 adjacent muscles, which anastomose with the popliteal, and the 

 peroneal branch, which supplies and runs under the peroneus, 

 and it finally divides about the tarsus into the great metatarsal 

 and perforating pedal arteries. 



The ARTERIA PEDIS PERFORANS, or PERFORATING PEDAL artery 

 passes through the tarsal joint, in a canal between the cuboid 

 and cuneiformes magnum and .medium, down the back of the 

 metatarsus, to the arterial arch formed by the plantar branches 

 of the posterior tibial artery. 



GREAT METATARSAL ARTERY. 



(FiG. 160. 5.) 



The great metatarsal artery originates at the proximal and 

 external aspect of the large metatarsal bone ; lying in the groove 

 between it and the small metatarsal bone, it insinuates itself 

 between them, passing under the osseous nodule of the latter ; 

 it gains the back of the large bone, passing through the bifurca- 

 tion of the suspensory ligament, and finally anastomoses with 

 the internal and sometimes the external interosseous plantar 

 branches of the posterior tibial ; thus forming the sesamoidean 

 arch, whence spring the external and internal digital arteries, 

 which grain the sides of the fetlock. 



