Death is the irreversible cessation of all biological functions that sustain an organism. To put it simply, it is the irreversible loss of the body's fundamental functions, including the central nervous system, circulatory system, and respiratory system. After death, all tissues and cells gradually lose their vitality. The brain, including the brainstem, ceases to function irreversibly. As blood circulation stops, cells are deprived of the oxygen and nutrients they need, rendering them unable to produce energy or eliminate waste. Moreover, the body's defense system, which controls the growth of bacteria, shuts down, leaving the body vulnerable.
