The Spleen. 253 



trathoracic growths, subphrenic abscess or pleurisy with 

 effusion, and, when so displaced, it may be detected by 

 the presence of the notches in the thin anterior border of 

 the organ. 



Splenic Reflexes. The spleen, being supplied 

 by projections from the solar plexus, is, therefore, pre- 

 sided over to a great extent by the splanchnics. These 

 splanchnic nerves contain certain fibres which arise from 

 a special centre in the medulla oblongata and pass down- 

 wards in the spinal cord to leave it in the dorsal region 

 and enter the splanchnics. Stimulation of these fibres 

 causes contraction of the organ (possibly this is an ex- 

 planation of the statement of Botkin that exhilarating 

 ideas diminish the size of the spleen). The same result, 

 i.e., the diminution in size may be brought about by elec- 

 trical stimulation over the region of the spleen, or by the 

 application of cold to the skin over the same region. The 

 latter phenomena are, in all probability, reflex actions, the 

 paths being from the lower dorsals, especially the eighth, 

 ninth and tenth, to the rami communicantes, and through 

 these to the splanchnics, and thence to the solar plexus and 

 the spleen. In splenitis, or inflammation of the spleen, 

 the local pain is probably due to stretching of the nerves 

 in the capsule, whereas, the pain, felt in the back, etc., is 

 reflexly transferred from the spleen to the dorsal nerves 

 through the paths above mentioned. Should the inflam- 

 matory action terminate in suppuration, the pus may 

 "point" at the abdominal parietes, adhesions having first 

 occurred between the serous covering of the spleen and the 

 parietal peritoneum, or it may perforate the diaphragm 

 and open into the pleura or lung, or, passing downwards, 

 may rupture into the stomach, colon or the abdominal 

 cavity itself. 



