FRONT OF THE FOREARM. 143 



branch, which, turning backward beneath the belly of the 

 snpinator longus, sends off numerous muscular twigs and 

 inosculates with the superior profunda branch of the bra- 

 chial ; in its course to the wrist it gives off many muscular 

 offsets, and, at the wrist, an anterior and posterior carpal 

 branch, which pass transversely across in front and behind, 

 anastomose with similar branches from the ulnar artery, 

 e superficialis voids branch arises from an uncertain point 



tear the wrist, and passes on to the ball of the thumb, 

 there to lose itself in the muscles or to join with the super- 

 ficial palmar arch; when given off high up, it occasionally 

 furnishes one or two digital branches. Having reached the 

 wrist, the radial artery winds round the base of the meta- 

 carpal bone of the thumb, beneath its extensor tendons, to 

 enter the palm of the hand between the two heads of the 



irst dorsal interosseous muscle; occasionally it curves 

 mud the radius higher up than this, and sometimes it 

 isses directly over the annular ligament into the palm ; 

 its whole course may also be superficial, owing to its high 



livision from the brachial (p. 106). The radial artery often- 



imes presents, especially in old and fat subjects, a series 

 flexuosities attended by dilatation; this condition is 



isually accompanied by a deposit of calcareous matter 

 in the arterial walls, varying in quantity; the same thing 

 may be noticed in other arteries, and in these cases, ossific, 

 or atheromatous deposits, will be found to a considerable 

 extent in the upper part of the aorta. 



The RADIAL NERVE is the larger of the two branches 

 into which the musculo-spiral nerve divides in front of the 

 external condyle; it accompanies the radial artery upon 

 its outer side beneath the supinator longus muscle ; near 

 the wrist it passes under the tendon of the supinator, 

 becomes cutaneous, and divides into two branches, one for 

 the back of the thumb, and the other for the back of the 

 hand. 



The MEDIAN NERVE passes between the two heads of the 

 pronator radii teres, and beneath the flexor sublimis digi- 

 torum, where it gives off the anterior interosseous and 

 muscular branches ; near the wrist it becomes superficial, 

 appearing along the outer border of the tendons of the lat- 

 ter muscle ; it here gives off a superficial palmar branch, 

 which passes over the annular ligament to the muscles and 

 integument of the ball of the thumb, while the main part 

 of the nerve continues beneath the ligament to the fingers. 



