372 



RESPIRATION 



[CH. XXIV. 



empty. The explanation of these appearances may be thus summar- 

 ised : when oxygenation ceases, venous blood at first passes freely 

 through the lungs to the left heart, and so to the great arteries. 



Owing to the stimulation of the vase-motor centres, by the venous 

 blood, the arterioles, particularly those of the splanchnic area, 

 are constricted; the arterial blood -pressure therefore rises, and the 

 left side of the heart becomes distended. The highly venous blood 



