The count down to Halloween has begun! For the month of October I will be exploring the dark side of science. This week's topic? Human cadavers. What really does happen to our bodies after we die? Medical science, organ donor, or cremation; there are many possibilities.
At the Forensic Anthropology Center at the University of Tennessee Knoxville scientists study human decomposition in different conditions. They have 1.3 acres of land they use for these studies. This helps police and other investigators as they identify corpses and create theories on how the person may have died.
There are five main stages of decomposition: fresh, bloat, active and advanced decay and dry remains. In the fresh stage the skin begins to turn blue (livor mortis) because the heart is no longer circulating the blood thus it is pulled to the lower parts of the body through gravity. The next part of the fresh stage, within 3 to 6 hours, is rigor mortis where the body becomes stiff. Algor mortis is the process of the body loosing heat after death. Soon the blowflies and flesh flies will begin to move in.
The bloat stage is where anorobic metabolism begins. The build up of hydrogen sulphide, carbon dioxide, and methane create distension in the body forcing fluids out of the body orifices and in some cases even causing rupture. This is the stage where the maggots will move in to further the process of decomposition.
During active decay the body will loose the most mass. This stage is when the maggots do the most eating of the body. The leakage of fluids into the surrounding environment will create a cadaver decomposition island, as in no grass will grow around the corpse.
Advanced decay is when the maggots have moved on to other pursuits as there is not as much cadaver material to feed on. The cadaver decomposition island will have more calcium, magnesium, phosphorus and potassium present as well as an increase in soil nitrogen
At this point all that remains is the dry remains, the bones, dried skin and cartilage. The grass and other plants will begin to regrow in the cadaver decomposition island.
Want to know more? Check out the book Stiff: The Curious Lives of Human Cadavers by Mary Roach or go to the UT Knoxville website for forensic anthropology.