174 Anatomy Applied to Medicine and Surgery. 



tical benefit of this association is evident in the rigidity of 

 the abdominal muscles that accompanies inflammation of 

 any of the abdominal viscera. There is no such bony 

 framework provided' for the protection of the delicate and 

 easily injured abdominal viscera, as there is, for the con- 

 tents of the thorax, skull or pelvis. It is true these ab- 

 dominal organs are guarded to some extent by the flexion 

 of the thorax and pelvis, and by the celerity with which 

 the upper extremities can be brought to a position of de- 

 fence when necessary, but, the principal means for the 

 protection of the viscera is, the almost instantaneous con- 

 traction of the abdominal muscles when a possible injury 

 is seen to threaten them, or, when even the slightest touch 

 on the skin indicates approaching danger. The fact of 

 the same nerves, viz., the intercostals, supplying the skin 

 and the muscles together, explains the readiness with 

 which this contraction occurs. Since the abdominal par- 

 ietes are supplied by the dorsal nerves, pain in the region 

 of the abdomen may be the result of irritation of these 

 nerves, as from caries of the dorsal vertebrae, etc., hence, 

 when examining a patient, and especially a child, it is well 

 to bear in mind this fact, since, it has not infrequently 

 happened that the so-called "stomach-ache" of childhood 

 has been dependent on some irritation of these intercostal 

 nerves, as from spinal disease, etc., rather than on some 

 purely local trouble. The arteries supplying the abdom- 

 inal parietes are : The lower intercostals, the superior, the 

 superficial and the deep epigastrics, the lumbar and the 

 ilio-lumbar. The lymphatics may be roughly stated to 

 pass up towards the axilla, from the region above the um- 

 bilicus, and, down towards the inguinal glands, from the 

 territory below that point. 



The veins correspond to the arteries, but in this region 

 there are in addition an occasional vertical vein on the side 



