148 



PRACTICAL PHYSIOLOGY 



more forcible. In the normal animal loss of consciousness now occurs 

 and convulsive movements. 



2nd stage : Respiration convulsive, less frequent; blood pressure rising; 

 heart slow. At the end of the second stage the pupils dilate and emission 



FIG. 148. Aortic pressure. Spinal cord divided in upper dorsal region. Effect of 

 placing animal in vertical head up posture. The heart emptied. On the return to the 

 horizontal posture the circulation was restored. (L.H.) 



takes place of urine and faeces. The veins are congested with black 

 blood. 





FIG. 149. Arterial pressure ; effect of asphyxia. Animal anaesthetised and 

 curarised. At A the artificial respiration was stopped. The large oscillations 

 are Traube-Hering curves. (L.H.) 



3rd stage : The inspirations, which have occurred at longer and longer 

 intervals, finally cease. The heart beats slowly and with great force. 

 Finally the heart accelerates, and the blood pressure falls to zero. 



