SUPERFICIAL DISSECTIONS 17 



The tendon passes through the deep notch between the anterior and 

 external tuberosities of the tibia, and is immediately succeeded by the 

 belly of the muscle. The latter is even better defined than is that of the 

 peroneus, and forms a prominent fusiform mass, which causes a well- 

 marked elevation of the skin in this region. 



The inferior tendon commences just above the hock, and passes 

 beneath all three annular bands. It then takes a course down the limb, 

 slightly to the outer side of the middle line. It is joined below the hock 

 by the tendon of the peroneus and below the fetlock by both branches of 

 the suspensory ligament. 



As it passes over the fetlock it is related to the anterior common 

 ligament, but at the pastern-joint it takes the place of the anterior liga- 

 ment and gives support by its deep face to the synovial membrane of the 

 joint as in the fore limb. 



This muscle is a flexor of the hock and an extensor of the fetlock 

 and inter-phalangeal joints. It is also a slight extensor of the stifle. It 

 is supplied by the anterior tibial nerve. 



The Extensor Brevis (24). — This small muscle is placed between 

 the tendons of the peroneus and extensor pedis. It arises from the 

 astragalus and os calcis, and is inserted into the tendon of the extensor 

 pedis, near where the peroneal tendon becomes united to the latter. 

 It assists the extensor pedis, and is supplied by the anterior tibial nerve. 



THE BLOOD-VESSELS 



The Arteries 



No vessels are represented in the upper half of the limb. 



Below the hock the Large Metatarsal Artery (21) makes its 

 appearance after having passed beneath the extensor brevis and the 

 tendon of the peroneus. It runs down the limb in the groove between 

 the large metatarsal and outer small metatarsal bones. Just above the 



