250 SURGICAL APPLIED ANATOMY, [chap. xv. 



the two interosseous vessels above, and with the deep 

 palmar arch below, by means of the perforating 

 branches from the latter vessel. The anastomosis 

 between the two palmar arches is well known, and is 

 freely established both by the main vessels themselves 

 and by the communion that exists between the digital 

 arteries from the superficial arch and the palmar inter- 

 osseous branches from the deeper vessel. In bleeding 

 from the palm, the simultaneous ligature of the 

 radial and ulnar arteries may also entirely fail in 

 those cases where the arches are freely joined, or are 

 more or less replaced by large and abnormal inter - 

 osseous vessels, or by a large "median" artery. 

 When either the radial or the ulnar part of the arches 

 is defective, the lack is usually supplied by the other 

 vessel ; and it is well to note that the deficiency is 

 most common in the superficial or ulnar arch. 

 Pressure applied to the palm to arrest bleeding is apt 

 to cause gangrene, owing to the rigidity of the parts 

 and the ease with which considerable pressure can 

 be applied. 



The radial artery, as it curves round the back of 

 the hand to reach the deeper part of the palm, is in 

 close contact with the carpo-metacarpal joint of the 

 thumb. This fact must be borne in mind in amputa- 

 tion of the entire thumb, and also in resection of the 

 first metacarpal bone. The superficialis volse, if large, 

 may bleed seriously. It adheres to the surface of 

 the annular ligament, and may therefore be difficult 

 to pick up when wounded. 



From the larger size and great number of the 

 lymphatics about the fingers and on the dorsum of the 

 hand, it follows that lymphangitis is more common 

 after wounds of those parts than it is after wounds 

 of the palm. 



The bones and joints. The inferior radio- 

 ulnar joint is supported by the powerful triangular 



