death science definition

The end of life of an organism or cell. In humans and animals, death is manifested by the permanent cessation of vital organic functions, including the absence of heartbeat, spontaneous breathing, and brain activity. Cells die as a result of external injury or by an orderly, programmed series of self-destructive events known as apoptosis . The most common causes of death for humans in well-developed countries are cardiovascular disease, cancer, Alzheimer's disease, certain chronic diseases such as diabetes and emphysema, lung infections, and accidents. See also brain death.