THE UMliS OF THE HOUSE 



91 



The distal interphalangeal articulation (articulatio phalangis 



terbise). — The joint between the second and third phalanges is one in 

 which movement is limited to flexion and extension. Movement, 

 moreover, is not very free owing to the inclusion of the joint in the 

 hoof. The dissector will observe that the articular surface of the third 

 phalanx is not, in itself, sufficiently extensive to accommodate the 



SI. interosseuB. 

 Second metacarpal bone. 



Lig. iutersesamoideum. 



Lig. sesanioideum rectum. 



Ligamenta volaria. 



Glenoidal lip. 



Lig. collaterale mediale. 



Lig. phalangosesamoideum. / £$ 



,] Third metacarpal bone. 



Fourth metacarpal bone. 



-«Lig. sesamoidemn laterale. 

 -.Lig. sesanioideum obliquum. 



51. flexor digitorum sublimis. 



Lig. sesanioideum collaterale 

 laterale. 



Sesamoid. 

 Third phalanx. 



Fig. 64. — Ligaments of the Volar (Posterior) Aspect of the Digit. 



whole of the distal end of the second phalanx. The sesamoid bone 

 completes the articular cavity. Between the ligamentous border of the 

 sesamoid and the immediately adjacent part of the third phalanx, short, 

 but strong, fibres form a phalango-sesamoidean ligament (ligamentum 

 phalangosesamoideum) that, while permitting a certain measure of 

 movement, retains the sesamoid firmly in position. 



The joint capsule (capsula articularis) is attached to the articular 

 margin of the three bones which enter into the formation of the joint. 

 In front (dorsal) it is intimately connected with the common extensor 

 tendon and the collateral ligaments. Behind the joint the capsule is 



