. ./A'.)/. /'(>A'/-:.IA'.\/. HAND. POSTERIOR /'./A'/'. 353 



membrane associated with both bones. For purposes of convenience call tlu- 

 extensor ossis metacarpi pollicis tlie strong muscle. Then say : 



1. The long muscle (the extensor longus pollicis) arises from the posterior 

 surface of the long bone (the ulna) and the interosseous membrane. 



2. The short muscle (the extensor brevis pollicis) arises from the posterior 



Articular branch o/,vi//" / ir 

 jirojiiii'in 



Brachialis antlcua 

 Bupinator longua, cut 



Common extensor tendon 



Extensor carpi radlalia longior 

 and brevior 



Sup in at or brevis 



Posterior interosteout artery 



Extensor oasis metaoarpi polliois 

 Supiiiator longus, out 



Extensor primi iuternodii pollicis 



Posterior annular ligament 



Extensor carpi radialia longior 



Radial artrry 



Dorsal is pollicis artery 



Extensor seoundi internodii 



pollicis 



First dorsal interoaaeous muscle 



Dorsali* indicia artery 



Pi-inceps pollicis artery 



Dorsal digital artery 



Tricep* 



Rete over olecranon 

 Interosseous recurrent artery 



A nconeus, cut 



Extensor carpi uluaris 

 Flexor oarpi ulnaris 



Origin of extensor aeoundi and 

 indicator 



Posterior branch of anterior interusseota 



artery 

 Interosseous membrane 



Posterior ulnar carpal artery 

 Extensor carpi radialis brevior 

 Posterior radial carpal artery 



Third dorsal interosttotu artery 

 Second dorsal intfrosseous artery 

 Metacarpal or first dorsal interossfoitt 

 artery 



FIG. 247. THE BACK OF THE FOREARM, WITH THE POSTERIOR INTEROSSEOUS ARTERY AND 



BRANCHES OK THE RADIAL AT THE BACK OF THE WRIST. 



(From a dissection in the Hunterian Museum.) 



surface of the short bone (the radius) and the interosseous membrane. Insertion 

 into the base of the first phalanx. 



3. The strong muscle (the extensor ossis metacarpi pollicis) arises from the 

 posterior surfaces of both the long and short bones (ulna and radius) and the 

 interosseous membrane. Insertion into base of metacarpal bone. 



