THE SESAMOIDEAN LIGAMENTS 



227 



moid ligament, and its deep face to the triangular rough area on the volar surface 

 of the first phalanx. The deep or cruciate sesamoidean ligaments (Ligg. sesamoidea 

 cruciata) consist of two thin layers of fibers which arise on the base of the sesa- 

 moid bones, cross each other, and end on the opposite eminence on the proximal 

 end of the first phalanx. 



The two short sesamoidean Ugaments (Ligg. sesamoidea brevia) are best seen 



Shin 

 Tendon of common e.Uensor 



Bursa 



Capsule of fcllock joint 

 Caciiij of fetlock joint 



Cavity of pastern joint 



Cavity of coffin joint ^s 



Corium of periople x, J7 / i 

 Periople 



Coronary corium 



Wall 



Laminx 



Middle sesamoidean ligament 

 Digital synovial sheath 

 Cavity of pastern joint 

 Superficial sesamoidean ligament 

 Deep flexor tendon 

 Distal end of digital sheath 

 12 



n 



Digital cushion 



Sole Corium of sole 

 Fig. 242. — Sagittal Section of Digit axd Distal P.^rt of Metacarpus of Horse. 

 A, Metacarpal bone; B, first phalanx; C, second phalanx; D, third phalanx; E, distal sesamoid bone; 1, volar 

 pouch of capsule of fetlock joint; 2, intersesamoidean ligament; 3, 4, proximal end of digital synovial sheath: 5, ring 

 formed by superficial flexor tendon; 6, fibrous tissue underlying ergot; 7, ergot; S, 9, 9', branches of digital vessels; 10, 

 distal ligament of distal sesamoid bone; 11, suspensory ligament of distal sesamoid bone; 12, 12', proximal and distal 

 ends of bursa podotrochlearis. By an oversight the superficial flexor tendon (behind 4) is not marked. 



by opening the joint in front and pushing the sesamoid bones backward; they 

 are covered by the synovial membrane. Each is a short band which extends from 

 the anterior part of the base of the sesamoid bone outward or inward to the posterior 

 margin of the articular surface of the first phalanx. 



The distal sesamoidean ligaments may be regarded as digital continuations 

 of the suspensory ligament, the sesamoid bones being intercalated in this remark- 

 able stay apparatus, by which the fetlock is supported and concussion diminished. 



