AND BLOOD PRESSURE 



147 



which shows what an effect such deep breathing has both on the 

 return of venous blood and on the resistance in the splanchnic area. 

 The action of abdominal breathing on the return of venous blood 

 may be easily demonstrated by opening the thorax of a cat just 

 above the diaphragm, and cutting a hole in the vena cava inferior. 

 With each descent of the diaphragm the blood spurts out. The 

 muscles of the abdomen and the levator ani support the abdominal 

 pressure, and the avoidance of prolapse of the viscera depends on 

 the proper exercise of these muscles and on the presence of an 

 adequate amount of fat in the belly. 



EFFECT OF MENTAL WORK AND EMOTION 



In curarised animals excitation of the cortex cerebri in the 

 motor areas of the limbs and trunk muscles raises the arterial 



A A A A I 

 / V 



Fi<;. 19. 1, Volume of uMominal organs; 2, volume of arm ; 3, respiration; 

 + , pleasant ; , - unpleasant taste. 



pressure, by causing contraction of the splanchnic area, and dilates 

 the blood vessels of the limbs. Dilatation of the splanchnic area 



