ANATOMY IX A NUTSHELL. 



The radial recurrent arises from the radial just below the elbow, passes 

 outward between the Supinator brevis and Supinator longus, also separating 

 the radial and posterior interosseous uerves; it then runs towards the elbow 

 between the Supinator longus and the Brachialis anticus to supply these mus- 

 cles and to anastomose with the anterior terminal branch of the superior pro- 

 funda. 



The muscular branches supply the muscles on the radial side of the fore- 

 arm. 



The anterior carpal arises near the lower border of the Pronator quadratus; 

 ii passes to the ulnar side ^\ the forearm under the tendons to anastomose with 

 anterior carpal of ulnar, thus forming the loop which gives branches to the 

 wrist-joint. 



The superficialis volae arises from the artery near the wrist where it is 

 about to wind around the carpus. It passes between the muscles of the ball of 

 the thumb, sometime- over them. It anastomoses with the ulnar, completing 

 the superficial palmar arch. The pulse may often be felt in this artery, as 

 well a.- in the radial, when it arises higher than usual. 



The branches in the wrist are the posterior carpal, metacarpal or first dor- 

 sal interosseous, dorsales pollicis, and dorsalis indicis. After the radial gives 

 off the anterior carpal it crosses the external lateral ligament to the base ofthe 

 metarcapal of the thumb, lying upon the scaphoid and trapezium. In this 

 situation it is crossed by the three extensors of the thumb, viz., Extensorossis 

 metacarpi pollicis which is a broad muscle and comes from both bones, 

 the Extensor longus pollicis which comes from the long bone or ulna, and the Ex- 

 tensor brevis pollicis which comes from the short bone or radius. It then passes 

 between the two heads of the first dorsal interosseous or Abductor indicis, into 

 tin' palm. It passes to the back of the hand for two reasons, first to supply 

 tin' hack of the hand on the radial side, and second for protection. 



The posterior carpal arises beneath the extensors of the thumb, passing 

 beneath the extensor tendon- of the forearm to join the posterior carpal of the 

 ulnar, making the posterior carpal arch. It uives off the second and third dor- 

 sal interossei which pass on the back of the Third and Fourth interossei mus- 

 cles to the metacarpophalangeal joint where it divides into digital branches to 

 supply the contiguous sides of the middle, ring, and little fingers. At their 

 proximal extremity they receive perforating branches from the deep palmar 

 arch. At the distal extremity they give perforating branches to the digital 

 branches to join the palmar digital arteries. 



The metacarpal or first dorsal interosseous may conn' from the posterior 

 carpal, bu1 it generally arises from the radial. It passes over the Second dorsal 

 interosseous muscle to the metacarpophalangeal joint where it is divided to 

 supply thr contiguous side- of the index and middle finders. At its proximal 

 extremity it receives perforating branches from the deep palmar arch; at its 

 distal extremity it gives branches to join the corresponding digital arteries. 

 The digital arteries end at the firsl interphalangeal joint where they join the 

 posterior branch of the collateral digital branches. 



The dorsales pollicis are two in number; they arise from the radial near 

 the base of the first metacarpal bone and pass along the sides of the dorsum of 

 the thumb. 



