FREE online courses on the Basics to Forensic Entomology - DEAD What happens
after that
Everybody will die, that is one thing that we are absolutely
certain of. What exactly is death, and what happens in the time after death?
From a biological point of view, death is a process, not an event. This is
because the different tissues and organs in a living body dies at different
rates. We can divide death into somatic death and cellular death. Somatic death
is when the individual is not longer a unit of society, because he is
irreversibly unconscious, and unaware of himself and the world.
Cellular death is when the cells quits respiration and
metabolism. When all cells are dead, the body is dead. But all cells do not die
simultaneously, except perhaps in a nuclear explosion. Even in a victim of a car
bomb, where the body becomes fragmented, individual cells will continue to live
for a few minutes or longer. Different cell types can live for different times
after cardiac arrest. Nervous cells in the brain are particularly vulnerable to
oxygen deprivation and will die within 3-7 minutes after complete oxygen
deprivation.
In many countries brain stem death is considered legal death,
even if the body is kept alive with artificial means. This opens up for organ
transplants of heart, liver and lungs, where the donor has to be dead.
What we will discuss in this course, is what happens after
cardiac arrest in a body which is lying dead outdoors (or indoors).
One of the first things that happen after death is that the
temperature in the body starts to drop. Before the temperature in the body core
drops, a temperature gradient must be established from the outside to the core.
After this gradient has become established the body temperature will drop with a
theoretically predictably rate. This fact can be used to estimate time of death.
Even if one succeeds in predicting when the temperature of the body core was 37
degrees Celsius, one has to remember that the time it takes to form the
temperature gradient will vary from individual to individual, and will vary from
almost no time, to over two hours.
After the onset of putrefaction (about two days after death)
the body temperature will increase again, due to the metabolic activity of the
bacteria and other decomposing organisms.
