Page:The Principles and Practice of Medicine.djvu/25

Rh impaired, in consequence of nutrition being generally defective, as for example in exhausting diseases. When persons, reduced by long-continued illness or want of proper food, die sud- denly, the immediate cause of death is cessation of the heart's action from impairment of the function of the muscular fibre. So also the muscular fibre may be impaired by the deposit of fatty particles in place of the muscular tissue, as happens in states of fatty degeneration.

Death by may be caused by—1st, some direct impedi- ment to the admission of air (Asphyxia* ); 2nd, lesion of that part of the nervous centre which is concerned in the reflex actions upon which respiratory movements depend (Coma).

1. Death by Asphyxia.—Air may be prevented from entering the chest by closure of the mouth or nostrils, by strangulation, by the presence of a foreign body in the rima glottidis, by spasm of the muscles by which that aperture is closed, or by pressure upon the walls of the chest and abdomen. It may, also, be excluded by disease of the lungs or bronchial tubes, or by those organs being compressed by tumours or collections of fluid in the pleural sac ; and lastly, the admission of oxygen is prevented by the presence of a foreign gas, such as hydrogen, which, although not in itself poisonous, renders a given quantity of atmospheric air deficient in its constituent gases. Death from asphyxia may also arise from obstruction to the circulation of the blood through the lungs, as in certain diseases of the heart.

The symptoms of impending death by apncea are, extreme distress, the face bloated and of a purple colour, the eyes injected and prominent, violent action of the respiratory muscles, vertigo, loss of consciousness, and coma. The sphincters after- wards become relaxed, and the heart gradually ceases to beat. In this kind of death the cavities of the right side of the heart are distended with blood, and a small quantity of venous blood is r;e^erally found in the left side. The engorgement of the right cavities exists in cases where there has been no mechan- ical obstruction to the pulmonic circulation, and even when the