62 ANATOMY AND PHYSIOLOGY 



The ligaments anterior, posterior, medial, and lateral to- 

 gether compose a large capsule. (They are attached to the 

 humerus above the olecranon fossa at the back, and above the coro- 

 noid and radial fossae in front.) The synomal membrane is 

 extensive. 



Annular ligament 

 Tendon of biceps 



Oblique ligament 



Upper edge of inter- 

 osseous membrane 



FIG. 57. MEDIAL VIEW OP THE ELBOW- JOINT. (Morris.) 



Motions. The elbow-joint proper is capable of flexion -and 

 extension only, like all hinge-joints. 



The radius and ulna are connected together at their extremities, making 

 rolling joints (see p. 18); their shafts give attachment to an interosseous 

 membrane of white fibrous tissue which almost fills the space between the 

 bones. 



Wrist- joint. Between the forearm and the carpus, having a 

 variety of gliding motions, but used principally as a hinge-joint. 

 Articular surfaces: Above the lower end of the radius and the 

 triangular cartilage (or articular disc) ; below the first row of carpal 

 bones (not including the pisiform) . The ligaments anterior pos- 

 terior, medial, and lateral enclose the joint like a capsule. 



Motions. Flexion, extension, and slight lateral bending (or 

 from side to side) making abduction and adduction. (If the hand 

 is bent far backward or over-extended, this is dorsal flexion.) 



