94 



Bones of the Upper Extremity. 



Tuberculum minus 

 Colluru anatomicum 



Tuberculum majus - S 



Sulcus 

 intertubercularis 



Collum chirurgicum 



Crista tuberculi 

 minoris 



Crista tuberculi 

 major is 



Caput burner! 



Tuberositas 

 deltoidea 



Foramen nutricium 



Facies anterior 

 lateralis 



Margo lateralis 



Margo_medialis 



Facies anterior 

 medialis 



Fossa 

 coronoidea 



Fossa 

 radialis . 



Epicondylus -| 

 lateralis 



Capitulum 

 humeri 



Trochlea humeri. 



Epicondylus medialis 



117. Right humerus, 



humerus, from in front. 



The humerus (upper arm bone) (see 

 also Figs. 118 122) is a long cylindrical bone 

 which articulates above with the shoulder 

 blade, below with the bones of the forearm. 

 It is divisible into a body or shaft, corpus 

 humeri, and two extremities. 



The corpus humeri (shaft) is more 

 cylindrical above, distinctly triangular below: 

 its surfaces are called the fades posterior, 

 the fades anterior medialis (0. T. internal 

 surface) and the fades anterior lateralis 

 (0. T. external surface); the posterior surface 

 is separated from the two anterior surfaces 

 by the margo medialis (0. T. internal border) 

 and the mar go lateralis (0. T. external 

 border) both of these being especially sharp 

 and prominent below. On the facies anterior 

 lateralis somewhat above the middle is a broad 

 rough surface, tuberosilas deltoidea (for the 

 m. deltoideus); behind this, on the posterior 

 surface lies a shallow groove, the sulcus nervi 

 radialis (0. T. mnscnluspiral groove) (for the 

 n. radialis), which begins on the medial margin 

 and descends like a long drawn-out spiral to 

 the lateral margin. A large foramen nutricium 

 is often noticeable near the middle on the 

 medial margin : it leads into a canalis nutridus 

 directe* I distal war* I . 



The upper extremity is broadened 

 and supports the caput humeri which is 

 covered with cartilage: this is nearly hemi- 

 spherical and directed upward and median- 

 ward. It is separated from the rest of the 

 bone by a constriction, the collum anatomicum 

 (anatomical neck). Close to this lie two 

 eminences : directed exactly lateralward is the 

 tuberculum majus (0. T. greater tuberosity), 

 in front of this directed forward, the tuber- 

 culum minus (0. T. lesser tuberosity); running 

 forward and downward from both of these are 

 ridges, the crista tuberculi majoris (0. T. 

 posterior bicipital ridge) and the crista tuber- 

 culi minoris (0. T. anterior bicipital ridge). 

 Between the tubercula and the cristae runs 

 the deep sulcus intertubercularis (0. T. bici- 

 pital groove) (for the tendon of the caput 

 longum m. bicipitis). At the junction of the 

 upper extremity with the corpus humeri lies 

 the collum chirurgicum (surgical neck). 



