788 



HUMAN ANATOMY, 



2. The Anterior Radial Carpal Artery. — 

 carpea volaris) (Fig. 712) is usually a small branch 



Fig. 715. 



Triceps, cut 



Olecranon process - 



Anconeus 



Interosseous 



recurrent artery 

 Extensor carpi 



ulnaris, cut 



Superior profunda 



artery 

 Biacliio-radialis 



Extensor carpi 



radialis longior 

 External condyle 



Head of radius 



Supinator brevis 



Posterior interosse- 

 ous artery 



Posterior interosse- 

 ous nerve 



Extensor carpi 



radialis brevier 



Extensor 



longus pollicis 



The anterior radial carpal (ramus 

 which arises from near the lo\\er 

 end of the antibrachial portion 

 of the radial. It passes inward 

 beneath the flexor tendons at 

 about the lower border of the 

 pronator quadratus, and breaks 

 up into a number of small 

 branches which anastomose 

 with branches from the anterior 

 ulnar carpal, the anterior inter- 

 osseous, and the recurrent car- 

 pals to form an anterior carpal 

 net-work. From this net-work 

 branches pass to the wrist and 

 to the carpal articulations. 



3. The Superficial Vo- 

 lar Artery. — The superficial 

 ^'oIar ( ramus volaris supertici- 

 alis) (Fig. 713) arises usually 

 just where the radial bends out- 

 ward and backward to reach the 

 posterior surface of the wrist. 

 It is usually rather slender, 

 although variable in size, and 

 is directed downward, passing 

 either over, through, or beneath 

 the adductor pollicis, supplying 

 that and the other muscles of the 

 thenar eminence, and terminates 

 usually by anastomosing with 

 the superficial palmar branch of 

 the ulnar to form the superficial 

 palmar arch. 



Variations. — The superficial 

 volar is somewhat variable both as 

 to size, origin, and mode of termina- 

 tion. It occasionally arises high up 

 upon the radial, and in such cases 

 that vessel passes to the posterior 

 surface of the arm at a much higher 

 level than usual. Not infrequently 

 it takes no part in the formation of 

 the superficial palmar arch, and 

 may terminate in the muscles of 

 the thenar eminence, the digital 

 branches being all given off by the 

 superficial palmar branch of the 

 ulnar ; or, on the contrary, appear- 

 ing as a well-developed stem, it 

 may divide distally into from one 

 to four digital arteries, the remain- 

 ing ones arising directly from the 

 superficial palmar branch of the 

 ulnar or partly from that and partly 

 from the median artery (page 784). 



4. The Posterior Ra- 

 dial Carpal Artery. — The 



posterior radial carpal (ramus 



carpeus (lorsalis) (Fig. 715) is a 



small branch which is given of? from the radial just as that vessel passes beneath the 



tendon of the extensor ossis metacarpi pollicis. It passes horizontally inward beneath 



Extensor indicis 



Posterior ulnar 



carpal artery 



Dorsal 



interosseous 



arteries 



Extensor ossis 

 metacarpi pollicis 



Extensor brevis 



pollicis 

 Anterior interosse- 

 ous artery 



Posterior radial 

 carpal artery 

 Kadial artery 



rsalis pollicis 



arter>- 

 Dorsalis 

 indicis artery 



Arteries of extensor surface of forearm and hand. 



