ASPHYXIA 163 



quantity of blood, insufficient exposure of the blood in the 

 lungs, etc. 



Asphyxia may be looked upon as exaggerated dyspnea. 

 The labored breathing of dyspnea becomes convulsive, and 

 finally collapse ensues. Respiration becomes shallow, con- 

 sciousness is lost, the pupils are dilated, opisthotonus devel- 

 ops, the reflexes disappear, and at last the heart stops beat- 

 ing. The skin and mucous membranes become blue from 



FIG. 52. 'The heart in the final stage of asphyxia. 



The letters have the same meaning as in Fig. 51; in addition, p.c. represents 

 the pulmonary capillaries. The right auricle and ventricle, and the pulmonary 

 artery, are fully distended, while the left cavities of the heart and the aorta 

 are nearly empty. (Kirkes after Sir George Johnson.) 



non-oxygenation of the blood. Asphyxia from submersion 

 is harder to overcome than from simple deprivation of air 

 outside the water. Resuscitation is extremely doubtful when 

 a person has been submerged as long as five minutes. 



While the phenomena of dyspnea and asphyxia are refer- 

 able to the lungs, it is not the need of air in these organs, but 

 of O in the tissues, which gives rise to the symptoms. The 

 non-oxygenated blood in asphyxia will not circulate through 

 the capillaries except with the greatest difficulty, and the 

 result is that it accumulates in the arterial system, dams 



