rj4 



THE SKELETON 



terminates infrriorlv in front of the styloid process; throughout the greater part 

 of its extent it is rounded, and affords origin to the //(wr y>/v>f(^K/(^^! r%/ton(?n ; m 

 its lower foiu-th it is rough and prominent for the jmmutor quadratus. The 

 posterior border extends from the tubercle, near the tip of the olecranon, to the 

 back part of the stvloid process. The upper three-fourths gives attachment to an 

 aponeurosis, from Which the flexor and extensor cariyi vlnarh and the flexor j^rofimdus 

 diiiitonim muscles arise. 



Fio. 1:50. —Thk Left Ulxa axd Kadils. (Postero-exterual view. 



Triceps 

 Capsular ligament 



^^^^^^ 



Lower limit of orbicular ligament 



Biceps 



Supinator brevis 



Extensor primi interuodii pollicis 



RADIUS 



Grooves for extensor oasis, and extensor 

 primi interuodii pollicis 



For extensor carpi radialis longior 



and brevior 



Extensor sccuudi interuodii pollicis 



OLECRANON 



SUBCUTANEOUS SURFACE 



£xtensor ossis metacarpi pollicis 



AN APONEUROSIS IS ATTACHED TO THIS BORDER 

 FROM WHICH THE flexor AND extensor 

 carpi ulnaris, AND flexor profundus 

 digitorum ARISE 



Extensor secundi Internodii pollicis 



ULNA 

 Extensor indicis 



— Extensor minimi digitl 

 Extensor carpi ulnaris 



Internal lateral ligament 



/j'/ \-\ Extensor carpi ulnaris 



Extensor communis digitorum Posterior 

 and extensor Indiois radio-carpal 



ligament 



Posterior radio-ulnar ligament 



Of the three surfaces, the anterior lies l)etween the anterior and interosseous 

 borders; it is concave for tlie greater ])art of its extent. The upper three-fourths 

 gives origin to the flexor profiindus diffitorum, the lower fourth to the pronator 

 quadrntm; the \\\t\wv limit of tlie surface for the pronator is sometimes indicated by 

 an oblicpie ridge. Tlie internal surface is bounded by the anterior and ])osterior 

 borders. The upper three-fourths is o(cu])ied l)y tlie flexor profundtix diqitorum; the 

 remainder is sul)cutaneous. The posterior surface" lies ])etween the interosseous 



