Bones of the Lower Extremity. 



133 



183. The Eight Astraga- 

 lus, s. Talus, 



from before and the inner side. 



184, The Right Astraga- 

 lus, s. Talus, 



from the outside. 



The astragalus or talus has a b o d y, n e c k and h e a cl. The 

 superior surface of the body is covered with cartilage and serves 

 for articulation with the tibia; the internal surface is also covered 

 with cartilage for articulation with the inner malleolus of the tibia, while 

 the larger external surface articulates with the external malleolus of 

 the fibula. The inferior concave surface articulates with the Os calcis. 



The anterior surface of the body is continued into the neck, 

 and that into the head ; the former is covered with cartilage on the inferior 

 surface for articulation with the sustentaculum of the Os calcis, the latter 

 covered with cartilage for articulation with the scaphoid bone. From 

 within and behind a groove, the Sulcus tali, runs externally and ante- 

 riorly. 



The astragalus is therefore in articulation with four bones: with the 

 tibia, the fibula, the Os calcis and the scaphoid. 



