Dead Humans: Human Decomposition and More
The Walking Dead’s new season has started. Zombies have once again resurrected from the dead. But why are we excited to see decomposed bodies walk across the Bible Belt in search of fresh goods? Why have zombies risen, not just from the dead but also in popularity? I personally like to see the work done by the make-up artists, kudos to them! If you recall in the opening segment of last week’s episode there was a scene where a zombie squeezed himself between the narrow space of two trucks, ripping his skin as if it was a piece of paper. After the scene, I was left contemplating how the body gets to that point. Though the scene was very extreme it lets our imagination lose!
Dead is inevitable. It is enigmatic. The topic of the afterlife and the human soul is left to personal beliefs; what we can discuss, is the physical transition of life and death. Mary Roach describes in Stiff: The Curious Lives of Human Cadavers ways in which doctors used to assess whether a person was dead or alive until mid-1800’s, she reports:
The soles of the feet were sliced with razors, and needles jammed beneath toenails. Ears were assaulted with…hideous shrieks, [insects] and excessive noises. A French physician invented a set of nipple pincers specifically for the purpose of reanimation. The seventeenth century anatomist Jacob Winslow entreated his colleagues to pour boiling Spanish wax on patient’s foreheads and warm urine into their mouths. For simplicity and originality, though, nothing quite matches the thrusting of ‘a sharp pencil’ up the presumed cadaver’s nose.
After the advent of the stethoscope in the mid-1800’s most of these practices vanished and were gradually replaced with the sounds of the heart, though many physician still felt that putrefaction was the only reliable way to really know if someone was dead or not. During the 1800’s in Germany and other parts of Europe, waiting mortuaries became popular. In these morgues cadavers were place in a warehouse separated by gender or social class into different rooms. Attendants were hired to keep watch for any signs of life through a system where a string was linked to the finger of the dead person and then to a bell. Proven unsuccessful, these mortuaries had close by the 1940’s.
It wasn’t until 1968 when the Journal of the American Medical Association published a paper by Harvard Medical School advocating that irreversible coma causing brain death be the new criterion for death. It would take a bizarre murder case in 1974 for the law to catch-up with medical science and proclaim brain death as the new measure of expiration. The brain survives for approximately six to ten minutes after blood supply has been cut off. During the French Revolution, it was speculated that beheadings caused less suffering than the old time hangings, until a well respected German anatomist S. T. Sömmering and French librarian, Jean Joseph Sue of the Paris School of Medicine agreed that heads could hear, smell, see, and think for approximately 10 seconds after being separated from the body. How did they arrived to those conclusions? I’ll let you do some search on that one.
So what are the stages of a decomposition? There are seven in total: pallor mortis, livor mortis, algor mortis, rigor mortis, putrefaction, decomposition, and skeletonization.
Pallor mortis/livor mortis: is post-mortem paleness. It happens 15 to 20 minutes after blood capillaries stop their function. Blood pools at the bottom due to gravity causing pallor in the upper portion and a purplish hue in the lower portion where blood pools, also known as livor mortis. This stage is of little use to forensic scientist, it tells little about the time of death and it is more noticeable in individuals of lighter skin tone.
Algor mortis: this is the stage in which body temperature fluctuates matching the temperature of its surroundings. In general, corpuses lose about 1.5 degrees Fahrenheit per hour until they reach the temperature of the air around them. In this stage the potassium level inside the gel substance of the eye is good indicator of time of death.
Rigor mortis: starts a couple of hours after death and is characterized by stiffness of skeletal muscle, usually starting in the neck and back. After 3 days forensic scientist use entomological clues (e.g., age of larvae).
Putrefaction: is organ liquefaction and breakdown of foul smelling proteins (putrescine and cadaverine). I presume this is the stage of the zombies in The Walking Dead!
Decomposition: is when the complex macromolecules (e.g., proteins, carbs) of the body are broken down to simpler forms. This is known as the recycling phase.
Skeletonization: is the last stage. Characterized by bone exposure, all tissue is broken down until nothing is left.
Two years ago I read an article in The Atlantic highlighting the “Body Farm” at the University of Tennessee. At the time it was the only institution of higher education carrying forensic experiments on dead bodies to study how the environment affects the rate of decomposition. Netflix has a great documentary about it. In fact there are many industries that employ cadavers for experimentation, e.g., from measuring speed impact in automobile collisions to bullet efficiency. Some scientist are also working on developing ways to dispose bodies more effectively, one such practice is call “tissue digestion” (don’t get scare now) also known as alkaline hydrolysis. In a “Tissue Digestor” the body is broken down completely by adding water and alkali, heating and agitating the system, in approximately 30 minutes the body liquifies and proteins, fats, carbohydrates are neutralized and run down the drain. The only remains are mineralized bone and teeth that gets thrown in land-fills. Let’s not forget to mention that this practice has only been done to dispose animals at veterinary schools; but think about it, this is an Eco-Friendly alternative to the polluting practice of incineration (I will leave a link at the bottom of this blog if you’re interested in more information).
Well it is Saturday and I have to get some anatomy and physiology studying done! As always, if this blog was of your liking do not forget to leave you kudos and subscribe. I’m always happy to hear from any of you so send me an email telling me what can be improved, what you like, don’t like!
And as always keep the flow of information going, until next time!
http://www.biosafeeng.com/tissue_digestion_vs_incineration