114 



THE SKELETON OF THE UPPER EXTREMITY 



x Great sigmoid cavity 



' Incisura semilunaris 



Coronoid process 



Processus coronoideus 



Small sigmoid cavity 



Incisura radialis 



Tuberosity of the ulna 



Tuberositas ulnae 



Nutrient foramen 



Foramen nutricium 



External or interosseous 

 border 



Crista interossea 



Anterior surface 

 Facies volaris 



Olecranon 



Olecranon 



Internal surface 



Facies medialis 



Posterior border 



Margo dorsalis 



Posterior surface 

 Facies dorsalis 



Articular circumference 

 Circumferentia articularis 



Styloid process 

 Processus styloideus 



FIG. 258. ANTERIOR ASPECT. FIG. 259. POSTERIOR ASPECT. 



THE ULNA OF THE RIGHT SIDE. 



Olecranon 



Olecranon 



Great sigmoid cavity 



' Incisura semilunaris 



Coronoid process 



Processus coronoideus 



Small sigmoid cavity 



Incisura radialis 



Tuberosity of the ulna 



Tuberositas ulnae 

 Supinator ridge 

 Crista m. supinatoris 



External or inter- 

 osseous border 

 Crista interossea 



Posterior surface 

 Facies dorsalis 



Head of the ulna 



" "Capitulum ulnas 



Articular circumference 



Circumferentia articularis 



\Stylold process 

 f rocessus styloideus 



FIG. 260. EXTERNAL ASPECT. 



Interosseous borders 

 Crista interossea 



Anterior border 

 Margo volaris 

 Internal surface 

 Facies medialis 



Posterior border 



Margo dorsalis 



Posterior surface 

 Facies dorsalis 



Anterior surface 

 Facies volaris , 



Anterior surface 

 Facies volaris 



Ulna Vi Radius 



Anterior border 

 Margo volaris 



External surface 

 Facies lateralis 



Posterior border 



Margo dorsalis 



Posterior surface 

 Facies dorsalis 



FIG 261. TRANSVERSE (HORIZONTAL) SECTION THROUGH THE MIDDLE OF THE ULNA AND 



THE RADIUS, WITH THE INTEROSSEOUS MEMBRANE, IN SUPINATION. 



Ossa antibrachii The bones of the forearm. 



