THE FOREARM AND HAND. 89 



muscles to the wrist, and in that case it would be felt pulsating beneath the skin in 

 the neighbourhood of the anterior ulnar vein (Vol. II, p. 445). 



The bifurcation of the brachial artery takes place opposite a spot a finger's 

 breadth below the centre of the bend of the elbow. From this point, the radial 

 artery runs downwards with a nearly straight course to the fore part of the styloid 

 process of the radius, being covered by the supinator longus as far as the centre of 

 the forearm, and superficial beyond this spot. The ulnar artery inclines, with a 

 slightly curved course, inwards to the middle of a line drawn from the back of the 

 internal condyle of the humerus to the outer side of the pisiform bone : this line 

 indicates in its whole extent the direction of the ulnar nerve in the forearm, in its 

 lower half that of the ulnar artery also. The latter is deeply placed beneath the 

 muscles arising from the internal condyle till within an inch of the wrist. 



THE WBIST AND HAND. 



At the front of the wrist, on the inner side, the pisiform bone can be grasped 

 between the fingers, and moved slightly from side to side ; below this, and a little 

 more externally, the hook of the unciform bone can be felt with difficulty. On the 

 outer side, a projection is felt just below and internal to the styloid process of the 

 radius, formed by the tuberosity of the scaphoid bone, and close below this, the ridge 

 of the trapezium is also to be distinguished. At the back of the wrist, on the inner 

 side, the pyramidal bone can be felt, and slightly external to the middle line of the 

 hand is a prominence, sometimes indistinct, but often very well marked, formed by 

 the styloid process on the base of the third metacarpal bone at its articulation with 

 the os magnum. 



At the metacarpo-phalangeal articulation of the thumb the sesamoid bones can 

 be felt ; and on the dorsal aspect of the hand the metacarpal bones and the 

 phalanges can be distinctly followed. 



At the outer side of the wrist, when the thumb is extended, there is a deep 

 hollow bounded by the prominent tendons of the extensor ossis metacarpi and 

 extensor brevis pollicis anteriorly and the extensor longus pollicis posteriorly ; the 

 latter tendon may be followed down over the metacarpal bone and first phalanx of 

 the thumb almost to its insertion. Beneath these tendons, and across the inter- 

 vening hollow, the radial artery runs in its course from the front to the back of the 

 wrist ; its direction may be marked by a line drawn from the fore part of the 

 styloid process of the radius to the upper end of the first interosseous space ; and 

 a considerable vein, ascending from the outer part of the hand, is usually to be seen 

 through the skin over the position of the artery. 



On the back of the hand, the tendons of the extensor communis digitorum and 

 extensor minimi digiti may all be recognized, together with the connecting band 

 between the innermost slip of the common extensor and the outer portion of the 

 little finger tendon. In some cases the tendon of the extensor indicis may also be 

 perceived on the inner side of the first slip of the extensor communis. Between the 

 first and second metacarpal bones is the abductor indicis muscle, which forms a 

 well-marked prominence when the thumb is brought to the side of the index finger, 

 and below this is the adductor transversus pollicis muscle contained in the fold of 

 skin passing across between the thumb and the outer margin of the palm. 



The palm of the hand is concave in the centre, where the skin is tightly adherent 

 to the palmar fascia, and raised on each side. The outer elevation (thenar) is 

 formed by the outer group of the short muscles of the thumb ; the inner (hypothenar) 

 by the short muscles of the little finger. From the central hollow of the palm a 

 slight groove is continued downwards to each of the fingers, corresponding to the 

 prolongations of the palmar fascia. The palm is traversed generally by four more or 



