igS Transactions of the Canadian Institute. [Vol. VII, 



If the distal end of the divided spinal cord be stimulated by the 

 Faradic current, the pressure in the carotid artery is decidedly raised, as 

 shown in Tracing 17. Here the animal, in which the spinal cord had been 

 previously divided in the lower dorsal region was placed feet-down at 

 43, with the result that the pressure fell. At 44 the distal end of the 



46 45 44 43 



Tracing XVII. — 1/2. — Spinal cord previously divided in lower dorsal region. 43 Vertical. 44 Faradic 

 stimulation of distal end of cord. 45 Horizontal. 46 Distal end ag^ain stimulated— no effect. 



divided cord was stimulated as mentioned, and a considerable rise in 

 pressure took place. At 45 the animal was replaced in the horizontal 

 position. This experiment again shows how dependent the general 

 blood pressure of the body is upon the vaso-motor tone of the vessels 

 in its lower part. When the animal was placed horizontal again, 



38 37 



Tracing XVIII. — 8/22. — Spinal cord previously divided opposite last dorsal vertebra. Animal 

 horizontal. 37 Distal end of cord stimulated by Faradic current. 38 Stimulus removed, 



similar stimulation of the distal end produced no effect. Tracing i8 

 shows only a slight rise on stimulation of the distal end of the cord 

 while the animal was horizontal. This is a result which one would 

 naturally expect. 



The vaso-motor influence of the lower part of the body is supposed 

 to be very limited and chiefly confined to the skin,^ The experi- 

 ments just related, however, would suggest that the vascular tone of the 

 lower part of the body is of considerable importance in the regulation of 

 the general arterial blood pressure. Without doubt the splanchnic area 

 is the one chiefly concerned in the regulation of the blood pressure, but 

 it is here suggested that the tone of the lower limbs is of more import- 

 ance in this regard than is generally recognized. 



Foster's Physiology, Part I, 



