Postmortem Guide
post·mor·tem (adj.)
1. Occurring or done after death.
2. Of or relating to a medical examination of a dead body
Seven stages after death in order:
Pallor Mortis:
Itâs a postmortem paleness which happens in those with light/white skin almost instantly (in the 15â25 minutes after the death) because of a lack of capillary (smallest blood vessels) circulation throughout the body. The blood sinks down into the lower parts (due to gravity) of the body creating Livor Mortis. Pallor Mortis has little to no use on determining the time of death because it happens to fast. If the body is found quickly, it can be said the death occurred either less than 30 minutes ago or more. While Pallor Mortis the lips also turn blue/purple from of lack of oxygen.Â
Hairy skin influences the results and any hair must be removed by shaving before colour determination,
Among the living, there is a skin colour difference between the sexes which disappears after death,
A living person can look so pale that âdeath-paleâ. Deep shock, also heart failure can make the face look gray; the person then also has blue lips.
Algor Mortis:Â
After the heart stops beating, the body immediately starts turning cold. This phase is also known as death chill. Each hour, the body temperature falls about 0.83 degrees Celsius (1.5 degrees Fahrenheit) until it reaches room temperature (which is 25 degrees Celsius (77 degrees Fahrenheit) .
The healthy body temperature is 36 degrees Celsius (96.8 degrees Fahrenheit).
Iâm going to do this over Celsius because of all the countries in the world only three of them donât use the metric system.
36-25=11 degrees Celsius [How much colder the body will get with Algor Mortis].
11/0.8 = 13.75
Meaning the body will take around 14 hours to reach room temperature after the moment of death.
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The wikipedia page however states that the body will lose 2° Celsius during the first hour and 1° Celsius per hour until the body nears ambient temperature (and letâs accept thatâs also room temperature - 25 degrees Celsius)
Then, the first hour the body will drop to being 34 degrees celsius- then 34-25= 9
This shows that the body will drop to room temperature in 10 hours after the moment of death.
The Glaister equation estimates the hours elapsed since death as a linear function of the rectal temperature:
 (98.4 degrees Fahrenheit - Rectal Temperature in Fahrenheit) / 1.5
This is used in forensics.
Of course all of these are considering that there are no other factors affecting the rate of algor mortis.
Rigor Mortis:
Temperature of the Body - Stiffness of the Body - Time Since Death
Warm                - Not Stiff           - Not Dead
Warm                - Stiff              - Dead between 3 - 10 hours
Cold                 - Stiff              - Dead between 10 - 38 hours
Cold                 - Not Stiff           - Dead for +36 hours
(Not precise)
At the time of death, a condition called âprimary flaccidity" occurs
Itâs one of the recognizable signs of death, caused by chemical changes in the muscles after death (later to be explained), causing the limbs of the corpse to become stiff and difficult to move or manipulate after the âprimary flaccidity". Rigor Mortis is reason why the word âstiff" is a slang term for a dead body. It progresses in a downward, head-to-toe direction most likely because the muscle groups on the face are smaller than the ones that are of the lower limbs (which is called Nystenâs law).Â
Nystenâs law:Â Rigor Mortis affects first the muscles of mastication (eating muscles, jaw etc.), next those of the face and neck, then those of the trunk and arms, and last those of the legs and feet.
It begins with the eyelids, neck, and jaw and then follows (including the internal organs). In humans, it commences after about two to four hours, reaches maximum stiffness after 12 to 18 hours (at this stage, you can move the joints only by force, breaking them in the process), and gradually dissipates until approximately 48 to 60 hours after death (which is when decay starts to set in). If the position in which a body is found does not match the location where it is found (for example, if it is flat on its back with one arm sticking straight up), that could mean someone moved it.
Rigor Mortis can be massaged out by the mortician doing the embalming process. Embalming chemicals act to fix (denature- meaning they canât work properly anymore) cellular proteins so they cannot act as a nutrient source for bacteria (embalming fluid also kills the bacteria themselves so they canât decompose the body - at least for a while until new ones come along). Depending on the the formaldehyde, the body can be made into one that is pliable or become hard as a rock. Body features are âset" by the mortician prior to injection of embalming fluid and massaged into the tissues. Formaldehyde fixes tissue or cells irreversibly, the end result also creates the simulation, via color changes, of the appearance of blood flowing under the skin and makes up for the paleness of Pallor Mortis.
If the ambient (room) temperature is too close to body heat, Algor Mortis will be quicker, and this would mean the body will get stiff with Rigor Mortis quicker. If the body is kept cold, Rigor Mortis could be postponed even a few days.Â
The onset of rigor mortis is affected by the individualâs age, sex, physical condition, and muscular build.
Rigor mortis may not be perceivable in many infant and child corpses due to their smaller muscle mass. If thereâs enough muscle mass in children, elderly and in those with a fever or a debilitating disease, it will progress quickly.
Physical exertion just prior to death: If someone dies while engaged in strenuous activity like exercising or struggling against drowning, rigor mortis can set in immediately (because this means more lactic acid being released and more muscles contracting even before death). This instant onset, sometimes called âcadaveric spasmâ. This is why the victim of a violent attack may still be clutching the attackerâs hair or a piece of clothing, because the muscles remain locked with Rigor Mortis.
Fat acts as insulation, causing rigor mortis to develop more slowly.
Because rigor mortis leaves a lot of room for doubt, forensic pathologists rely on other indicators that provide greater certainty as to time of death. These include:
Body temperature: The body cools at the rate of 1.5 to 2 degrees per hour. A body that registers approximately 92 degrees Fahrenheit (33.33 degrees Celsius) has been dead about four hours.
Stomach contents:Â By determining the degree of digestion of the last meal, examiners can gauge how long the person lived after eating.
Insect activity: Flies gather around the eyes, mouth and other openings to feed on the bodyâs fluids. Forensic entomologists can determine approximately how long someoneâs been dead by observing the life cycle of the flies, as well as their eggs and larvae. (See below for more)
Cause of Rigor Mortis:
(Taken almost all from here because it explains it well)
Thick filaments, made of the protein molecule myosin.
Thin filaments, made of the protein molecule actin.
When you lift a weight or scratch your head, a nerve impulse sets off a biochemical reaction that causes myosin to stick to actin. These two molecules lock together, pulling the muscleâs thick and thin filaments toward each other.
When thousands of filaments pull together all at once, over and over, you have a muscle contraction. You can read more about all the steps of this process in How Muscles Work.
Once the actin and myosin molecules stick together, they stay that way until another molecule, adenosine triphosphate (ATP), attaches to the myosin and forces it to let go. Your body uses the oxygen you breathe to help make ATP. That oxygen supply ends, of course, with death. When the person canât breath with oxygen and create ATP with it, the body resorts to breathing without oxygen, creating lactic acid in the muscles, pumping (or making it diffuse) calcium ions (lactic acid) to places where there are less of it and in here it bounds with troponin to let myosin and actin slide together. Without the new ATP that would normally come with breathing, the thick and thin filaments canât slide away from each other (causing a permanent state of muscular contraction) until it starts to break down with enzymes or bacteria during decomposition.
During rigor mortis, another process called autolysis takes place. This is the self-digestion of the bodyâs cells. The walls of the cells give way, and their contents flow out. Rigor mortis ends not because the muscles relax, but because autolysis takes over. The muscles break down and become soft on their way to further decomposition.
Basically, a biochemical chain reaction that causes a living personâs muscles to move stops working when someone dies. When the reaction stops, the muscles become locked in place.
Livor Mortis:Â
(Post-mortem lividity, hypostasis, suggillation) Â
Itâs one of the signs of death, a settling of the blood in the lower (dependent) portion of the body, causing a purplish red discoloration of the skin. It stars before Rigor Mortis When the heart stops functioning and is no longer agitating the blood, heavy red blood cells sink to the bottom of the corpse with gravity. Livor mortis starts twenty minutes to three hours after death and is congealed in the capillaries in four to five hours. Maximum lividity occurs within 6â12 hours. The intensity of the color depends upon the amount of reduced hemoglobin in the blood. The discoloration does not occur in the areas of the body that are in contact with the ground or another object, in which capillaries are compressed. As the vessel wall become permeable due to decomposition, blood leaks through them and stains the tissue. This is the reason for fixation of hypostasis. Livor Mortis can even help you with knowing when the person died.Â
If the Livor Mortis is not where where itâs suppose to be, where depending on how the body is located where gravity pulls down (for example if the body is sitting on a chair but the Livor Mortis is on the back instead of the feet), it means the body is moved.Â
Putrefaction:
2â3 days: Discoloration appears on the skin of the abdomen. The abdomen begins to swell due to gas formation.
3â4 days: The discoloration spreads and discolored veins become visible.
5â6 days: The abdomen swells noticeably and the skin blisters.
2 weeks: The abdomen is bloated; internal gas pressure nears maximum capacity.
3 weeks: Tissues have softened. Organs and cavities are bursting. The nails fall off.
4 weeks: Soft tissues begin to liquefy and the face becomes unrecognizable.
(The decomposition of organic matter (proteins) by bacteria and fungi that results in bad smelling gas and the liquefaction of most organs.)
In terms of thermodynamics, all organic tissue is a stored source of chemical energy and when not maintained by the constant biochemical efforts of the living organism it will break down into simpler products.
The breakdown of proteins in a decomposing carcass is a spontaneous process but one that is accelerated as the anaerobic microorganisms (organisms that can live without oxygen), already present in the digestive tract when it was alive, consume and digest the proteins that comprise the creatureâs cells.
As cells and their proteins are digested, the tissues of the body are left in a weakened state. Proteins are broken down into smaller components and these are excreted by the bacteria. The excreted components, which include gases carry the putrid odor associated with a decomposing body. The gases are initially constrained within the body cavities but diffuse though adjacent tissues and into the circulatory system. Once in the blood vessels, the gases can then spread to other parts of the body. The result is visible bloating of the torso and then limbs. The increased internal pressure due to the rising volume of gas also helps to weaken and separate tissues. At some point, some part of the body will rupture, releasing the gas. As the bacteria consume all available proteins, the process of decomposition progresses into the next stage: skeletonization.
The exact rate of putrefaction is dependent upon many factors such as weather, exposure and location. Thus, refrigeration at a morgue or funeral home can slow down the process, allowing for burial in three days or so following death without embalming. The rate increases dramatically in tropical climates.
This phase is delayed by the embalming process, but eventually the body will succumb. Enzymes in the pancreas make the organ begin to digest itself. Microbes will tag-team these enzymes, turning the body green from the belly onwards (the body first turns green, then purple, then black as it progresses).Â
After putrefaction, decay moves quickly to turn the body into a skeleton. However, some bodies take an interesting turn on the way. If a body comes into contact with cold soil or water, it may develop adipocere, a fatty, waxy material formed from the bacteria breaking down tissue. Adipocere works as a natural preservative on the inner organs. It can mislead investigators into thinking a body died much sooner than it actually did, as was the case of a 300-year-old adipocere corpse recently found in Switzerland.
Decomposition:
-Stages of DecompositionÂ
1. Fresh
The fresh stage begins immediately after the heart stops beating. Since blood is no longer being pumped through the body it drains to the dependent portions of the body, under gravity, creating an overall bluish-purple discolouration (Livor Mortis). Shortly after death, within two to four hours (depending on conditions), the muscular tissues become rigid and incapable of relaxing (Rigor Mortis). From the moment of death, the body begins losing heat to the surrounding environment, resulting in an overall cooling (Algor Mortis).
Once the heart stops, chemical changes occur within the body and result in changes in pH, causing cells to lose their structural integrity. The loss of cell structure brings about the release of cellular enzymes capable of initiating the breakdown of surrounding cells and tissues. This process is known as autolysis. Visible changes caused by decomposition are limited during the fresh stage, although autolysis may cause blisters to appear at the surface of the skin.
Oxygen present in the body is quickly depleted by the aerobic (working with oxygen) organisms found within. This creates an ideal environment for the growth of anaerobic (working regardless of oxygenâs presence) organisms. Anaerobic organisms, originating in the gastrointestinal tract and respiratory system, begin to transform carbohydrates, lipids (fat), and proteins (muscle), to yield organic acids (propionic acid, lactic acid) and gases (methane, hydrogen sulfide, ammonia). The process of microbial growth within a body is referred to asputrefaction and leads to the second stage of decomposition, known as bloat.
Blowflies and flesh flies are the first carrion insects to arrive, and seek a suitable oviposition site.
2. Bloat
The bloat stage provides the first clear visual sign that microbial growth is underway. In this stage, anaerobic metabolism takes place, leading to the accumulation of gases, such as hydrogen sulphide, carbon dioxide, and methane. The accumulation of gases within the bodily cavity causes the distention of the abdomen, the eyes to bulge out of their sockets, the tongue to swell and protrude and gives a cadaver its overall bloated appearance,Â
The gases produced also cause natural liquids and liquefying tissues to become frothy. As the pressure of the gases within the body increases, fluids are forced to escape from natural orifices, such as the nose, mouth, and anus, and enter the surrounding environment. The buildup of pressure combined with the loss of integrity of the skin may also cause the body to rupture (In rare instances, this gas has created enough pressure after a few weeks to cause decomposing pregnant women to expel the fetus in a process known as coffin birth.)
If insects have access, maggots hatch and begin to feed on the bodyâs tissues. Maggot activity, typically confined to natural orifices and masses under the skin, causes the skin to slip and hair to detach from the skin. Maggot feeding, and the accumulation of gases within the body, eventually leads to post-mortem skin ruptures which will then further allow purging of gases and fluids into the surrounding environment. Ruptures in the skin allow oxygen to re-enter the body and provide more surface area for the development of fly larvae and the activity of aerobic microorganisms.Â
3. Active Decay
Active decay is characterized by the period of greatest mass loss. This loss occurs as a result of both the feeding of maggots and the purging of decomposition fluids into the surrounding environment. The purged fluids accumulate around the body and create a cadaver decomposition island (CDI). Liquefaction of tissues and disintegration become apparent during this time and strong smell persists. The end of active decay is signaled by the migration of maggots away from the body to pupate.
4. Advanced Decay
Decomposition is largely inhibited during advanced decay due to the loss of readily available cadaveric material. Insect activity is also reduced during this stage. When the carcass is located on soil, the area surrounding it will show evidence of vegetation death. The CDI surrounding the carcass will display an increase in soil carbon and nutrients, such as phosphorus, potassium, calcium, and magnesium; changes in pH; and a significant increase in soilnitrogen.
5. Dry/Remains
During the dry/remains stage, the resurgence of plant growth around the CDI may occur and is a sign that the nutrients present in the surrounding soil have not yet returned to their normal levels. All that remains of the cadaver at this stage is dry skin, cartilage, and bones, which will become dry and bleached if exposed to the elements. If all soft tissue is removed from the cadaver, it is referred to as completely skeletonized, but if only portions of the bones are exposed, it is referred to as partially skeletonized.
Skeletonization:
Skeletonization refers to one of the final stages of decomposition, during which time the last vestiges of the soft tissues of a corpse or carcass have decayed or dried to the point that the bones of the skeleton are exposed. By the end of the skeletonization process, all soft tissue will have been eliminated, leaving only disarticulated bones.
In a temperate climate, it usually requires three weeks to several years for a body to completely decompose into a skeleton, depending on factors such as temperature, presence of insects, and submergence in a substrate such as water. In tropical climates, skeletonization can occur in weeks, while in tundra areas, skeletonization may take years, or may never occur if subzero temperatures persist. Natural embalming processes in peat bogs or salt deserts can delay the process indefinitely, sometimes resulting innatural mummification.
The rate of skeletonization and the present condition of the corpse can be used to determine the time of death.
After skeletonization has occurred, if scavenging animals do not destroy the bones, acids in many fertile soilstake about twenty years to completely dissolve the skeleton of mid- to large-size mammals, such as humans, leaving no trace of the organism. In neutral-pH soil or sand, the skeleton can persist for hundreds of years before it finally disintegrates. Alternately, bones occasionally undergo fossilization, converting into more durable minerals that can persist indefinitely.
1. Nail and Hair Growth
Despite popular belief, hair and nails donât actually grow after the body is dead. The body simply dehydrates after death and the skin shrinks, retracting around the nail beds and the scalp, making hair and nails appear to look longer but actually not growing.Â
2. Muscle Movements, Erections and Ejaculation
Although the brain may die, other areas of the nervous system may still be active. Nurses report seeing reflex action, which involves nerves sending signals to the spinal cord and not the brain (your brain can die with your heart still going but it canât happen vice versa), leading to muscle twitches and spasms after death. Some even say theyâve seen shallow chest movements after death.Â
When the heart stops forcing the blood around the body, it pools in whatever area is lowest (Livor Mortis). Sometimes people die standing up and sometimes people die lying face down. Meanwhile, for all that talk of relaxing muscles after death, it doesnât last forever. Certain types of muscle cells are activated by calcium ions as previously explained in Rigor Mortis, muscles contract but they relax afterwards as well. This can lead to ejaculation. Itâs real. It happens.
3. Has the Body Been Moved?
If Livor Mortis is not in the places it should be, then the body has been moved as explained in the Livor Mortis section.
If the way the body the body was locked with Rigor Mortis doesnât match the way the body is when itâs found, the body has been moved.Â
After death, a succession of fungi, bacteria and animals will colonize the dead body. The substrate on which the body is lying will also change over time. Leakage of fluids from the dead body will lead to the disappearance of certain insects, and other insects will increase as the time goes. A forensic entomologist can then look for how long the body has been there by looking at the fauna at the body, and also estimate the time the body has been lying there by sampling soil insects underneath the dead body. If there is a difference in the estimates, and the analysis of the soil suggests a short postmortem interval, and the analysis of the body fauna suggests a longer postmortem interval, one can suspect that the body has been moved. One can also see that a body has been lying at a particular place long time after the body has been removed, both by botanical means, and by analysis of the soil fauna.
Some times dead bodies are found in concealed environments, where blowflies have no access. If there are blowflies, it means that the body has been moved there. Some Calliphorids are heliophilic, that is, they prefer to lay their eggs on warm surfaces, which means that they usually occur where the bodies lies in sunny places. Other blowflies prefer shade. For example, Lucilia species prefer sunlight, and Calliphora prefer more shady conditions. Some species are synanthropic and occurs in urban areas; other species occur in rural areas. Calliphora vicina is a synantropic fly, very common in cities, and Calliphora vomitoria is a more rural species.
4. CellsÂ
Body cells burst open. The process in which the human body decomposes starts just minutes after death. When the heart stops beating, thereâs Algor Mortis. Almost immediately, the blood becomes more acidic as carbon dioxide builds up (yâknow, since the boyâs not breathing anymore). This causes cells to split open, emptying enzymes into the tissues, which start to digest themselves from within.
5. Embalming
Rigor Mortis can be massaged out by the mortician doing the embalming process. Embalming chemicals act to fix (denature- meaning they canât work properly anymore) cellular proteins so they cannot act as a nutrient source for bacteria (embalming fluid also kills the bacteria themselves so they canât decompose the body- or at least slow it down). Depending on the the formaldehyde, the body can be made into one that is pliable or become hard as a rock. Body features are âset" by the mortician prior to injection of embalming fluid and massaged into the tissues. Formaldehyde fixes tissue or cells irreversibly, the end result also creates the simulation, via color changes, of the appearance of blood flowing under the skin and makes up for the paleness of Pallor Mortis.
Embalming fluid is injected into the stomach cavity of the deceased during embalming. Many other bodily fluids may be drained or aspirated and replaced with the fluid as well. The process of embalming is designed to slow decomposition of the body so it looks natural.
Arterial solution may include:
Preservative (Arterial) Chemical
Water Conditioner
Cell Conditioner
Dyes
Humectants
Anti-Edemic Chemicals
Additional Disinfectants
Water
Cavity Fluid
For more explanations and terms
Extra information:
During the American Civil War Dr. Thomas Holmes developed an embalming fluid made with arsenic for preservation.
Thereâs a house in British Columbia thatâs made entirely out of embalming fluid bottles.
There are beauticians for the dead and kits made especially for the dead. It includes wound filler, lip wax, old age cosmetics, adult, peach, suntan, deep flesh, and other pieces that apply specifically to the dead. In addition, a good mortician closes the jaw with two wires stapled into the upper and lower gums. The point is to bury the dead looking as lifelike and good as possible.Â
6. Estimating Time of Death with Forensic Enthomology
After the initial decay, and the body begins to smell, different types of insects are attracted to the dead body. The insects that usually arrives first is the Diptera, in particular the blow flies or Calliphoridae and the flesh flies or Sarcophagidae.
The females will lay their eggs on the body, especially around the natural orifices such as the nose, eyes, ears, anus, penis and vagina. If the body has wounds the eggs are also laid in such. Flesh flies do not lay eggs, but deposits larvae instead.
After some short time, depending on species, the egg hatches into a small larvae. This larvae lives on the dead tissue and grows fast. After a little time the larva molts, and reaches the second larval instar. Then it eats very much, and it molts to its third instar. When the larvae is fully grown it becomes restless and begins to wander. It is now in its prepupal stage. The prepupae then molts into a pupae, but keeps the third larval instars skin, which becomes the so-called puparium. Typically it takes between one week and two weeks from the egg to the pupae stage. The exact time depends on the species and the temperature in the surroundings.
The theory behind estimating time of death, or rather the postmortem interval with the help of insects are very simple: since insects arrive on the body soon after death, estimating the age of the insects will also lead to an estimation of the time of death.
For more information on how to estimate the age of blowfly, eggs, larvae, pupae and adults (also just more information generally on insects)Â here.
7. 10 Cool Things Your Body Can Do After You Die
8. Other Uses of the Body
Skin: Anything that can be done with animal skin! Jackets, drums, rugs, furniture, you name it (I suggest looking up Ed Gein or Ilse Koch.)
Fat: Soap or candles can be made out of fat.Â
Bones: Bones can be used for making furniture or objects.
Guts: Violin strings or prophylactics. Â
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Sources:
http://en.wikipedia.org/wiki/Livor_mortis
http://www.mnn.com/health/fitness-well-being/stories/5-weird-things-that-happen-after-you-die
http://health.howstuffworks.com/diseases-conditions/death-dying/rigor-mortis-cause1.htm
http://health.howstuffworks.com/diseases-conditions/death-dying/rigor-mortis-cause2.htm
http://en.wikipedia.org/wiki/Rigor_mortis
http://science.howstuffworks.com/life/human-biology/dying4.htm
http://www.ncbi.nlm.nih.gov/pubmed/10741481
http://www.thefreedictionary.com/postmortem
http://en.wikipedia.org/wiki/Embalming_chemicals
http://answers.yahoo.com/question/index?qid=20080907112606AAxN8IT
http://medical-dictionary.thefreedictionary.com/Nystenâs+law
http://www.cienciaforense.com/pages/entomology/overview.htm#hasthe
http://dictionary.reference.com/browse/putrefaction
http://en.wikipedia.org/wiki/Putrefaction
http://www.tunalilar.com/weird-facts-about-death/
http://science.howstuffworks.com/life/human-biology/dying4.htm
http://www.anomalies-unlimited.com/Death/Stages.html
http://science.howstuffworks.com/body-farm.htm
