490 



ARTERIES. 



inosculates with the digital branch of the superficial palmar arch, and supplies 

 the adjoining sides of the index and middle fingers. 



The dorsales pollicis are two small vessels which run along the sides of the 

 dorsal aspect of the thumb. They arise separately, or occasionally by a com- 

 mon trunk, near the base of the first metacarpal bone. 



The dorsalis indicis, also a small branch, runs along the radial side of the back 

 of the index finger, sending a few branches to the Abductor Indicis. 



The princeps pollicis arises from the radial just as it turns inwards to the deep 

 part of the hand ; it descends between the Abductor Indicis and Adductor Pol- 

 licis, along the ulnar side of the metacarpal bone of the thumb, to the base of 

 the first phalanx, where it divides into two branches, which run along the sides 



of the palmar aspect of the thumb, 



Fig. 287Ulnar and Radial Arteries. Deep View. and form an arc ^ n the under sur- 

 face of the last phalanx, from which 

 branches are distributed to the in- 

 tegument and cellular membrane of 

 the thumb. 



The radialis indicis arises close to 

 the preceding, descends between the 

 Abductor Indicis and Adductor Pol 

 licis, and runs along the radial side 

 of the index finger to its extremity, 

 where it anastomoses with the col- 

 lateral digital artery from the super- 

 ficial palmar arch. At the lower 

 border of the Adductor Pollicis, this 

 vessel anastomoses with the princeps 

 pollicis, and gives a communicating 

 branch to the superficial palmar 

 arch. 



The perforating arteries, three in 

 number, pass backwards between 

 the heads of the last three Dorsal 

 Interossei muscles, to inosculate with 

 the dorsal interosseous arteries. 



The palmar interosseous, three or 

 four in number, are branches of the 

 deep palmar arch; they run for- 

 wards upon the Interossei muscles, 

 and anastomose at the clefts of the 

 finarers with the digital branches 



O o 



of the superficial arch. 



ULNAR ARTERY. 



The Ulnar Artery, the larger of 

 the two subdivisions of the brachial, 

 commences a little below the bend 

 of the elbow, and crosses the inner 

 side of the forearm obliquely in- 

 wards, to the commencement of its 

 lower half; it then runs along its 

 ulnar border to the wrist, crosses 

 the annular ligament on the radial 

 side of the pisiform bone, and passes 

 across the palm of the hand, forming 



