QUESTIONS AND ANSWERS 55 



first bones of the upper and lower rows and the outer metacarpal 

 bone. 



4. Internal lateral, from the inner side of the radius to the prin- 

 cipal and inner metacarpi, as well as to the capsular ligament. 



Name the bones and ligaments of the fetlock joint. 



Bones : Metacarpus, first phalanx, and two sesamoids. 



Ligaments: Intersesamoid, between the two sesamoids; lateral 

 sesamoid, between the sides of the sesamoid and the upper extremity 

 of the first phalanx; inferior sesamoid, of three fasciculi from the 

 posterior surface of the first phalanx to the sesamoid bones ; external 

 and internal lateral, from the metacarpus to the sides of the 

 first phalanx; an anterior, between the anterior surfaces of both 

 bones; a posterior, or suspensory ligament of the fetlock, from the 

 first and second bone of the inferior carpal row and posterior face 

 of the principal metacarpus to the top of the sesamoids, where it 

 divides into two fasciculi which pass forward and are inserted into 

 the anterior extensor of the phalanges. 



What is the function of the suspensory ligament? 



It acts as a mainstay or brace to the foot, and assists in preventing 

 ' jar from concussion when the fore limbs are brought to the ground 

 in locomotion. 



Describe the first interphalangeal articulation. 



This is an imperfect ginglymus, between the os sufifraginis and 

 OS coronse. Ligaments : two lateral ligaments between the sides of 

 the bones; one posterior ligament, or glenoidal fibrocartilage 

 attached to the first and second phalanges by six bands, increases 

 the articular surface below and forms a sheath for the passage of 

 the perf orans tendon. 



Movements : Flexion, extension and some lateral motion. 



Describe and discuss the functions of the lateral cartilages. 



The lateral cartilages, two in number, are composed of fibrous 

 and cartilaginous tissue, and are the shape of an oblique parallelo- 

 gram. They are prolonged behind the third phalanx and are 

 attached in front to the anterior lateral ligament, behind, to the 

 basilar and retrossal processes and plantar cushion. They are thin 

 above with a notch posteriorly for vessels; thick below, concave 

 internally, with vascular foramina, and convex externally, with 

 foramina for vessels. 



In association with the plantar cushion they act as cushions in 

 preventing jar and allowing for expansion when the foot is brought 

 in contact with the ground. 



