TRADITIONAL CONCEPT OF DEATH
OF AN ORGANISM
All living organisms take in oxygen by respiration, distribute
the oxygen to peripheral tissues through circulation, and then excrete metabolites
by means of the circulation and through respiration. Respiration and circulation
are vital to the living organism. Respiration is the functional expression of the
brainstem, and cessation of brainstem functions leads to the cessation of respiration.
Because the brainstem maintains its function through its supply of oxygen and nutrients,
cessation of circulation ultimately leads to cessation of respiration. The functions
of the brain, heart, and lungs are mutually dependent and share the basic role of
maintaining life. An organism dies when one of these life-sustaining organ systems
ceases to function. The traditional concept of death of an organism emphasized the
cessation of respiration or circulation, without consideration of the role of the
brain. This occurred because assessment of brain function was not easy to accomplish.
When mechanical ventilation was not widely used, cessation of brain functions related
directly to cessation of respiration, and assessment of brainstem functions was unnecessary.
 |
