What happens to the corpse after a month. The rotting and decomposition of a corpse is the last form of human existence. Not everything goes according to plan

The version officially accepted is that it takes at least fifteen years to completely decompose a buried body in a coffin. But at the same time, after eleven or a maximum of thirteen years, re-burial is allowed in the same grave. Since practice shows that this time is quite sufficient for the final decomposition and the last refuge and human remains, which means that the land can be used again.

The internal organs and tissues of a person begin to self-digest immediately after death. And after a certain period of time, decay begins. Until the moment of burial, the body of the deceased is embalmed or cooled so that it looks presentable. But after it is underground, the restraining factors cease to operate and the inevitable destruction of the body by the process of decomposition begins. The result is bones, liquids, gases and salts.

The human corpse can be compared to the most complex ecosystem. It lives and feeds on a huge number of microorganisms. Disabling immunity shortly after death allows microbes to colonize all organs and tissues. Their process of feeding on cadaveric fluids leads to the further development of putrefaction. After some time, complete decay of all tissues occurs and a bare skeleton remains, which is also subject to destruction, with the exception of a few especially strong bones.

What happens to a person after death in a coffin in a year

By the end of the first year, the process of decomposition of residual soft tissues had not yet ended. Practical experience indicates the absence of a cadaverous smell during the excavation of the grave in a year, which indicates the cessation of decay. And the remaining tissues either slowly smolder, becoming nitric or carbonic acid, or the process has already completely ended, and only bones remain. This stage is called skeletonization.

Sometimes a certain amount of tendons or some parts of the body that are dry and dense remain on the skeleton. Then begins the process of mineralization, which can last up to thirty years. Its result is the loss of the body of all unnecessary minerals, which turns it into unconnected bones. In this state, the remains can lie almost forever.

What happens to the coffin after burial

For the manufacture of the bulk of the coffins today, an ordinary pine article is used. This material, in the presence of constant moisture, takes only two to three years to turn into dust and crumble. This explains the fact that during the excavations almost never find the remains of the tree from which the coffin was made.

If they want the last refuge of a person to last longer, then it is treated with varnish or made from other types of wood, which are distinguished by hardness and durability. If a person was sent on his last journey in a metal coffin, then he can be preserved for more than a dozen years.

The decomposition of a buried body has several stages that vary in time. It is directly dependent on the environment in which it is located, and in what condition it was buried.

As a rule, the coffin with the deceased is given to the ground on the third day after his death. An increase in this time period is not advisable, not only because it is so conditioned by customs, but also by the elementary laws of biology. If the deceased person is not buried for five or seven days, then this procedure will have to be performed in a tightly closed coffin.

During this time, there will be a massive development of autolysis and putrefaction, accompanied by the destruction of internal organs. The result of these processes will be the formation of putrid emphysema on the surface of the entire body, and bloody fluid will begin to flow from the mouth and nose. This can be prevented only by embalming the body or placing it in the refrigerator.

Autolysis or self-digestion

This is the name of the first stage of decomposition, which begins almost immediately after the death of a person. Digestion of cells occurs as a result of the breakdown of cell membranes, accompanied by the release of enzymes from the cell structure. The most important are cathepsins, which are active inside lysosomes, leading to the destruction of trapped cellular molecules.

The beginning of this process is not affected by any microorganisms, since it starts on its own. First of all, under the influence of autolysis fall internal organs containing the largest amount of cathepsin:

• Brain.
• A medulla found in the adrenal glands.
• Spleen.
• Pancreas.

Further, all cells of the body undergo metamorphoses. The consequence of this is rigor mortis, which is explained by the combination of troponin and calcium coming out of the interstitial fluid. Myosin and actin combine, which leads to muscle contraction. The absence of ATP does not allow the cycle to complete, and therefore muscle relaxation begins only after the start of the decomposition process.

Partially, autolysis is influenced by various bacteria spreading from the intestine throughout the body. The source of their nutrition is the fluid that flows from decaying cells. They, in the full sense of the word, spread throughout the body, using blood vessels for movement. Bacteria first reach the liver. For this, the first twenty hours from the moment of death are enough for them.

rotting

A little later than autolysis, putrefaction begins to develop. The extent to which this will happen is influenced by the presence of several factors:

• What state was the person in before death?
• Under what circumstances did he die?
• What is the temperature and humidity regime of the soil.
• What kind of clothes was he wearing?

The mucous membranes and skin are the first to be affected. If the level of humidity of the earth in the place of burial is increased, then rotting develops quite quickly, the same thing happens in the case of blood poisoning. In cold regions, this process is slower. In addition, the inhibitory factors are:

• Insufficient amount of moisture in the corpse.
• Very tight clothing worn over the body.
• The presence in the body of strong poisons.

The myths about "groaning corpses", common among the people, are provoked precisely by the process of decay. This phenomenon has a scientific name - vocalization. The process of decomposition of a corpse is accompanied by the formation of gases that accumulate in the body cavities. If the body has not yet rotted, then the gas finds natural openings to escape.

When used as such vocal cords, a sound similar to a groan or wheeze is heard. If all the processes went quickly, then this can happen at the moment the coffin is lowered into the grave. It is not difficult to imagine the reaction of those who see off the deceased on their last journey.

The change of the body in the coffin begins at this stage with the hydrolysis of proteins by proteases of microbes and dead cells of the body. Proteins are gradually broken down to polypeptides and below. Their place is occupied by free amino acids. It is they who, when transformed, become the source of the cadaverous smell. The process is accelerated by the appearance of mold on the surface of the corpse, as well as its settlement with nematodes and maggots. Under their mechanical influence, the tissue is destroyed.

First of all, the liver, spleen, intestines and stomach decompose, which is explained by the abundance of enzymes in them. For this reason, the deceased often has a rupture of the peritoneum. The process of decay is accompanied by the release of cadaveric gas that fills the cavities of a deceased person.

Clear signs of the onset of decay include the following:

• The body turns green. The reason for this lies in the formation in the iliac region of sulfhemoglobin, a product of hydrogen sulfide and hemoglobin.
• Putridity of the vascular network. The blood that remains in the veins begins to rot, which leads to the formation of iron sulfide.
• Cadaveric emphysema. The corpse swells due to the pressure of the gas produced during the process of putrefaction.
• The corpse glows in the dark. It is explained by the production of hydrogen phosphide. But this occurrence is rare.

Smoldering

With the greatest speed, the decomposition process occurs during the first six months after burial. But sometimes, instead of rotting, smoldering begins. This happens when there is little moisture in the grave, but a lot of oxygen. As a result, cadaveric gas ceases to be produced and carbon dioxide is released instead.

Two more options - saponification and mummification

There are cases when the corpse neither rots nor decays. This can happen either as a result of special processing, or due to the presence of an environment that is not conducive to the development of these processes. There are two options left:

• Mummification is when the body dries up to such an extent that there is simply nothing to decompose.
• Soaping is the formation of a fat wax.

If the soil in which the burial is made is extremely dry, natural mummification of the corpse may occur. The bodies of those people who, before death, experienced severe dehydration of the body, aggravated by cadaveric drying after death, are well mummified.

In addition, artificial mummification is sometimes carried out, which can be achieved as a result of embalming or treatment with special chemicals that can slow down the decomposition process.

The adiposity is the diametrical opposite of mummification. For its formation, an environment with high humidity is needed, which makes the corpse inaccessible to oxygen, without which neither rotting nor smoldering is possible. In such conditions, the washing of the body begins. Scientists call this process anaerobic bacterial hydrolysis.

Ammonia soap is the main component of the fat wax. It is formed from the muscles, subcutaneous fat, skin, mammary glands and brain. All other parts of the body may remain unchanged or rot.

Decay is a complex set of processes of decay of tissues of a corpse, occurring as a result of the vital activity of microorganisms that multiply intensively after the death of a person, when all the protective-immune barriers that restrain this reproduction during life disappear. Rotting mainly comes from the action of aerobic bacteria that live in the human body during his lifetime: Escherichia coli, Proteus group, hay bacillus group, cocci. Anaerobic microorganisms have less effect. The specific putrefactive odor is mainly due to hydrogen sulfide and its derivatives mercaptans formed during the breakdown of proteins.

The first distinct signs of rotting of a corpse may appear within a day after death. They are expressed in a dirty green coloration of the skin of the iliac regions due to the formation of sulfhemoglobin in the vessels abdominal wall(a product of the combination of hemoglobin with hydrogen sulfide). Further at a temperature environment+ 20 - + 35 ° С rotting usually develops as follows. Dirty green coloration extends to the trunk, head and limbs and by the end of the second week covers the skin of the entire corpse. Against this background, brown stripes of a tree-like branching subcutaneous venous network often appear.

As a result of the formation of a large amount of putrefactive gases, the corpse swells, its facial features change. All corpses in this stage of decay acquire almost the same appearance, which makes it difficult to identify them (Fig. 89). When feeling the corpse, a crunch is felt from the developed subcutaneous putrefactive emphysema. Because of the extravasation of fluid, approximately 4-6 days after death, blisters filled with fetid contents begin to form.

A sharp swelling of the corpse can lead to tears in clothes, in some places the skin of the corpse also bursts, sometimes simulating damage. An increase in intra-abdominal pressure can cause post-mortem "delivery" in dead pregnant women and post-mortem "vomiting" from squeezing food masses out of the stomach. Hair, nails and epidermis are separated from rotten corpses with a slight mechanical impact. Simultaneously with the external manifestations of decay, the disintegration of internal organs occurs. The brain decomposes faster than others, it turns into a greenish structureless mushy mass.

Due to the destruction of the skin and muscle tissue, gases are released from the corpse into the environment, it gradually decreases in size, and the ongoing decay processes lead to the complete destruction of soft tissues. What remains is a skeleton covered in a dirty, sticky mass. Cartilage and ligamentous apparatus are destroyed last of all, and bones can be preserved for many years. Under favorable conditions, the soft tissues of a corpse located on the surface of the earth can completely decompose within 3-4 summer months. Slightly slower is rotting in water and even more slowly in corpses buried in the ground. The soft tissues of a corpse in a wooden coffin are completely destroyed in 2-3 years.

The rate of decomposition of a corpse is affected by a large number of endo- and exogenous factors, so it is almost impossible to judge the severity of decay on the prescription of death. Optimal conditions for the vital activity of bacteria and, accordingly, for the development of decay, they consist in a certain ratio of temperature and humidity. Rotting develops most quickly at an ambient temperature of about + 30 -4 - + 40 ° C and moderate humidity. It completely stops at temperatures around 0 °C and above + 55 °C and slows down sharply in the temperature range from 0 °C to + 10 °C. In winter, corpses can stay in cold rooms for several weeks without signs of decay.

During decay, significant changes in the concentration of alcohol in the tissues and fluids of the corpse occur, and this is associated not only with the post-mortem diffusion of alcohol from the stomach, but also with its post-mortem formation and destruction in decaying tissues. Therefore, when examining alcohol intoxication in cases of examining corpses in a state of pronounced putrefactive decomposition, only one question can be resolved - did the deceased take alcohol shortly before death [Novikov P.I., 1967]. For forensic chemical research in these cases, the muscles of the limbs, the stomach with its contents and urine are removed.

When corpses are buried in dry sandy soil and in crypts, when they are in attics under iron roofs in summer and in other similar conditions with sufficient ventilation in the presence of dry warm air, the processes of decay quickly stop and the corpse becomes mummified. At

mummification, the corpse dries up, its soft tissues become hard, the skin becomes brownish-brown, sometimes almost black

Color, its mass decreases sharply.

The corpses of children and malnourished persons undergo mummification faster. Distinguish artificial and natural mummification. An example of the first is not only the mummies of the ancient Egyptians, but also the mummification that occurs after the modern preservation of the corpse.

The forensic significance of mummification lies primarily in the fact that it preserves to some extent the appearance of the corpse, and this allows you to determine its gender, height, age, identify injuries and individual anatomical features, and in some cases identify.

The significance of mummification in determining the prescription of death is small, since the rate of drying depends on a combination of many factors that are difficult to account for. It is believed that complete mummification of an adult corpse occurs in 6-12 months, but it can occur even faster, even in 30-35 days.

If the corpse falls into cold water or into moist clay soil, then decay also soon stops, and after a while the soft tissues of the corpse turn into fat wax.

The process of fat wax formation consists in the decomposition of fats into glycerol and fatty acids (oleic, palmitic, stearic), and the latter, reacting with calcium and magnesium salts contained in water or soil, form solid and water-insoluble soaps. Therefore, the fat wax is, in its chemical composition, a mixture of solid fatty acids and their salts (soaps).

The tissues of a corpse, which are in the state of a fat wax, appear as a dense, homogeneous amorphous mass, in which only in some places it is possible to reveal single elements of their histological structure. Externally, the fat wax has the appearance of a gray-pink or gray-yellow mass of a rather dense consistency, crumbling in places and emitting an unpleasant rancid odor. The formation of fat wax begins already 2-3 months after the corpse enters the appropriate conditions, and for the complete transformation of all tissues and organs into fat wax, a period of about 1 year is needed. Children's corpses turn into adiposity faster - after 4-5 months.

Due to the absence of any regularities in the rate of formation of fat wax, this phenomenon can be used to determine the prescription of death with great care. The forensic meaning of adiposity is similar to that of mummification. Zhirosk to some extent preserves the appearance of the corpse and the damage it has. In a forensic chemical study, poisons, in particular alcohol, can be detected.

Peat tanning

This type of late conservation change occurs when a corpse enters a peat bog. In the water of such swamps, a large amount of humic acids and other tannins found in peat are dissolved. The corpse under their action seems to be tanned, the skin integuments thicken and acquire a dark brown color, the internal organs sharply decrease in size, the bones become soft. The corpse, which is in a state of peat tanning, is preserved for many years.

Other types of natural preservation of corpses

Corpses are well preserved at low ambient temperatures, when they get into water with a high concentration of salts, into oil and other liquids with preservative properties. Frozen corpses persist indefinitely.

Image copyright getty

The decomposition of the human body after death is a very curious topic, if you muster up the courage and take a closer look at the details, the correspondent believes.

"It's going to take a lot of work to straighten it all out," dissector Holly Williams says, raising John's arm and gently bending his fingers, elbow and hand on it. "As a rule, the fresher the corpse, the easier it is for me to work with him."

Williams speaks in a low voice and carries himself positively and easily, contrary to the nature of his profession. She practically grew up in a family funeral home in the north of the US state of Texas, where she now works. She had seen dead bodies almost daily since childhood. She is now 28 years old and, according to her, she has already managed to work with about a thousand corpses.

She is in charge of collecting the bodies of the recently deceased in the metropolis of Dallas - Fort Worth and preparing them for burial.

“Most of the people we go after die in nursing homes,” says Williams. “But sometimes there are victims of car accidents or shootings. It also happens that we are called to pick up the body of a person who died alone, lay for several days or weeks and has already begun to decompose. In such cases, my work is greatly complicated. "

By the time John was brought to the funeral home, he had been dead for about four hours. During his lifetime, he was relatively healthy. He worked all his life in the oil fields of Texas and therefore was physically active and in good shape. He quit smoking decades ago and drank alcohol moderately. But one cold January morning, an acute incident happened to him at home. heart attack(caused by some other, unknown causes), he fell to the floor and died almost immediately. He was 57 years old.

Now John lies on Williams' metal table, his body wrapped in a white sheet, cold and hard. His skin is purplish-gray, indicating that the early stages of decomposition have already begun.

self absorption

A dead body is actually far from being as dead as it seems - it is teeming with life. Increasingly, scientists are leaning toward viewing the rotting corpse as the cornerstone of a vast and complex ecosystem, emerging shortly after death, flourishing and evolving through decay.

Decomposition begins a few minutes after death - a process called autolysis, or self-absorption, starts. Shortly after the heart stops beating, cells become starved of oxygen, and as toxic by-products accumulate chemical reactions cells become more acidic. Enzymes begin to absorb cell membranes and leak out when cells are destroyed. This process usually begins in the enzyme-rich liver and in the brain, which contains a lot of water. Gradually, all other tissues and organs also begin to disintegrate in a similar way. Damaged blood cells begin to flow out of the destroyed vessels and, under the influence of gravity, move into the capillaries and small veins, causing the skin to lose color.

Image copyright getty Image caption Decomposition begins within minutes of death

The body temperature begins to decrease and eventually equalizes with the ambient temperature. Then comes rigor mortis - it starts with the muscles of the eyelids, jaw and neck and gradually reaches the torso and then to the limbs. During life, muscle cells contract and relax as a result of the interaction of two filament proteins, actin and myosin, which move along each other. After death, cells lose their energy sources, and filament proteins freeze in one position. As a result, muscles stiffen and joints become blocked.

In these early post-mortem stages, the cadaveric ecosystem consists mainly of bacteria that also live in a living human body. A huge number of bacteria live in our bodies, different nooks and crannies of the human body serve as a haven for specialized colonies of microbes. The most numerous of these colonies live in the intestines: there are trillions of bacteria - hundreds, if not thousands of different species.

The intestinal microcosm is one of the most popular areas for research in biology, general state human health and a huge range of different diseases and conditions, from autism and depression to disturbing intestinal syndrome and obesity. But we still know quite a bit about what these microscopic passengers do in our lifetime. We know even less about what happens to them after we die.

immune collapse

In August 2014, forensic expert Gulnaz Zhavan and colleagues from the University of Alabama in the US city of Montgomery published the first ever study of thanatomicrobiome - bacteria that live in the human body after death. Scientists have made such name from the Greek word "thanatos", death.

“Many of these samples came to us from criminal investigations,” says Zhavan. “When someone dies as a result of suicide, murder, drug overdose or a car accident, I take samples of their tissues. Sometimes there are ethically difficult moments, because we need the consent of relatives."

Image copyright Science Photo Library Image caption Soon after death, the immune system stops working, and nothing prevents bacteria from spreading freely throughout the body.

Most of our internal organs do not contain germs during life. However, shortly after death, the immune system ceases to function, and thus nothing prevents it from spreading freely throughout the body. Usually this process begins in the intestines, at the border of the small and large intestines. The bacteria living there begin to absorb the intestines from the inside, and then the tissues surrounding it, feeding on the chemical mixture that flows from the collapsing cells. These bacteria then invade the blood capillaries digestive system and to the lymph nodes, spreading first to the liver and spleen, and then to the heart and brain.

Zhavan and her colleagues took liver, spleen, brain, heart and blood samples from 11 cadavers. This was done in the interval from 20 to 240 hours after death. To analyze and compare the bacterial composition of the samples, the researchers used two state-of-the-art DNA sequencing technologies in combination with bioinformatics.

Samples taken from different organs of the same corpse turned out to be very similar to each other, but they were very different from samples taken from the same organs in other dead bodies. Perhaps to some extent this is due to the difference in the composition of the microbiomes (sets of microbes) of these bodies, but it may also be the time that has passed since death. An earlier study of decomposing mouse carcasses showed that the microbiome changes dramatically after death, but the process is consistent and measurable. Scientists were eventually able to determine the time of death to within three days within a nearly two-month period.

Unappetizing experiment

Zhavan's findings suggest that a similar "microbial clock" seems to work in the human body as well. Scientists have found that bacteria reach the liver about 20 hours after death, and it takes them at least 58 hours to get to all the organs from which tissue samples were taken. Apparently, bacteria spread systematically in a dead body, and counting the time after which they enter a particular organ may be another new way to determine the exact moment of death.

Image copyright Science Photo Library Image caption Anaerobic bacteria convert hemoglobin molecules into sulfhemoglobin

"After death, the bacterial composition changes," says Zhavan. "They are the last to reach the heart, brain, and reproductive organs." In 2014, a group of scientists under her leadership received a $200,000 grant from the US National Science Foundation to conduct further research. "We will use next-generation genome sequencing and bioinformatics to find out which organ has the most accurate timing of death - we don't know yet," she says.

However, it is already clear that different sets of bacteria correspond to different stages decomposition.

But what does the process of carrying out such a study look like?

Under the city of Huntsville in the US state of Texas in a pine forest lies half a dozen corpses in various stages of decomposition. The two freshest, limbs spread apart, are laid out closer to the center of a small fenced enclosure. Much of their droopy, blue-grey skin is still intact, the ribs and ends of their pelvic bones protruding from the slowly rotting flesh. A few meters away lies another corpse, now essentially a skeleton, its black, hardened skin stretched over its bones, as if it were wearing a shiny latex suit from head to toe. Farther away, behind the remains scattered by the vultures, lies a third body, protected by a cage of wooden planks and wire. It is nearing the end of its post-mortem cycle and has already been partially mummified. There are several large brown mushrooms growing where his belly once was.

natural decay

For most people, the sight of a rotting corpse is at least unpleasant, and more often than not, it is repulsive and frightening, like a nightmare. But for the Southeast Texas Applied Forensics Science Lab, it's business as usual. This facility opened in 2009 and is located on 100 hectares of forest owned by Sam Houston University. In this forest, a plot of about three and a half hectares has been allocated for research. It is surrounded by a three-meter-high green metal fence with barbed wire running on top, and inside it is divided into several smaller sections.

At the end of 2011, university employees Sybil Buchely and Aaron Lynn and colleagues left two fresh husks there to decompose in natural conditions.

Image copyright getty Image caption Bacteria reach the liver about 20 hours after death, and it takes them at least 58 hours to get to all other organs.

When bacteria begin to spread from the digestive tract, starting the process of self-absorption of the body, putrefaction begins. This is death at the molecular level: the further disintegration of soft tissues, their transformation into gases, liquids and salts. It also goes to early stages decomposition, but gains full momentum when anaerobic bacteria come into play.

Putrefactive decomposition is the stage at which the baton passes from aerobic bacteria (which require oxygen to grow) to anaerobic bacteria - that is, those that do not need oxygen.

During this process, the body becomes even more discolored. Damaged blood cells continue to leak out of the disintegrating vessels, and anaerobic bacteria convert hemoglobin molecules (which carry oxygen around the body) into sulfhemoglobin. The presence of its molecules in stagnant blood gives the skin a marbled, greenish-black appearance, characteristic of a corpse in the stage of active decay.

Special Habitat

As the gas pressure builds up in the body, abscesses appear over the entire surface of the skin, after which large areas of the skin separate and sag, barely holding on to the decaying base. Eventually the gases and liquefied tissues leave the corpse, usually exiting and flowing out of the anus and other orifices of the body, and often through torn skin on other parts of it. Sometimes the gas pressure is so high that the abdominal cavity bursts.

Image copyright Science Photo Library Image caption Different sets of bacteria correspond to different stages of decomposition

Cadaveric distention is generally considered to be a sign of transition from early to late stages of decomposition. Another recent study showed that this transition is characterized by noticeable changes in the set of cadaveric bacteria.

Buchelly and Lynn took samples of bacteria from different parts of the body at the beginning and end of the bloating stage. Then they extracted the microbial DNA and sequenced it.

Buchelly is an entomologist, so she is primarily interested in the insects inhabiting the corpse. She views the dead body as a special habitat for various kinds necrophage insects (corpse eaters), and in some of them the entire life cycle takes place entirely inside the corpse, on it, and in its vicinity.

When a decomposing organism begins to leave liquids and gases, it becomes completely open to the environment. At this stage, the corpse's ecosystem begins to manifest itself especially rapidly: it turns into the epicenter of the vital activity of microbes, insects and scavengers.

larval stage

Two types of insects are closely associated with decay: carrion flies and gray blowflies, as well as their larvae. The corpses give off a foul, sickly-sweet smell, caused by a complex cocktail of volatile compounds that constantly changes as they decompose. Carrion flies sense this smell with the help of receptors located on their antennae, sit on the body and lay their eggs in holes in the skin and in open wounds.

Each female fly lays about 250 eggs, from which small larvae hatch in a day. They feed on rotting meat and molt into larger larvae, which continue to eat and molt again after a few hours. After feeding for some time, these already large larvae crawl away from the body, after which they pupate and eventually transform into adult flies. The cycle repeats until the larvae no longer have food left.

Image copyright Science Photo Library Image caption Each female fly lays about 250 eggs.

Under favorable conditions, an actively decaying organism serves as a haven for a large number of third-stage fly larvae. Their body mass produces a lot of heat, causing the internal temperature to rise by more than 10 degrees. Like flocks of penguins around the South Pole, the larvae in this mass are in constant motion. But if the penguins resort to this method to keep warm, then the larvae, on the contrary, tend to cool down.

"It's a double-edged sword," explains Buchely, sitting in his university office, surrounded by large toy insects and cute monster dolls. "If they are on the periphery of this mass, they risk becoming food for birds, and if they remain center - they can just weld. Therefore, they constantly move from the center to the edges and back. "

Flies attract predators - beetles, ticks, ants, wasps and spiders that feed on fly eggs and larvae. Vultures and other scavengers, as well as other large meat-eating animals, can also come to feast.

Unique composition

However, in the absence of scavengers, the fly larvae are engaged in the absorption of soft tissues. In 1767, the Swedish naturalist Carl Linnaeus (who developed a unified classification system for flora and fauna) noted that "three flies are able to devour the carcass of a horse with the same speed as a lion." Larvae of the third stage massively crawl away from the corpse, often along the same trajectories. Their activity is so high that at the end of decomposition, their migration routes can be observed as deep furrows on the soil surface, diverging in different directions from the corpse.

Each species of living being that visits a dead body has its own unique set of digestive microbes, and in different types soils are inhabited by different colonies of bacteria - their exact composition, apparently, is determined by factors such as temperature, humidity, soil type and structure.

Image copyright Science Photo Library Image caption Fly larvae are engaged in the absorption of soft tissues

All these microbes are mixed with each other in the cadaveric ecosystem. Arriving flies not only lay eggs, but also bring their own bacteria with them, and carry away strangers. The liquefied tissues flowing out allow bacterial exchange between the dead organism and the soil on which it lies.

When Buchely and Lynn take bacteria samples from dead bodies, they find microbes that originally lived on the skin, as well as others brought in by flies and scavengers, as well as from the soil. "When the liquids and gases leave the body, the bacteria that lived in the intestines leave with them - more and more of them begin to be found in the surrounding soil," Lynn explains.

Thus, each husk appears to have unique microbiological characteristics that may change over time to suit the conditions of its particular location. By understanding the composition of these bacterial colonies, the relationships between them, and how they affect each other as they decompose, forensic scientists may someday be able to gain much more information about where, when, and how the person under investigation died.

Mosaic elements

For example, identifying DNA sequences in a corpse that are specific to certain organisms or soil types can help forensic scientists link a murder victim to a specific geographic location, or even further narrow the search for evidence to a specific field in some area.

"There have been several trials in which criminal entomology has really come into its own, providing the missing pieces of the puzzle," Bucely says. She believes that bacteria can provide additional information and serve as a new tool for determining the time of death. "I hope that in five years we will be able to use bacteriological data in court," she says.

Image copyright Science Photo Library Image caption Carrion flies are closely associated with decay

To this end, scientists are carefully cataloging the types of bacteria that live on and off the human body and studying how the composition of the microbiome varies from person to person. "It would be great to have a data set from birth to death," Buceli says. "I would like to meet a donor who would allow me to take bacterial samples during life, after death, and during decay."

"We're studying the fluid that leaks out of decaying bodies," says Daniel Wescott, director of the Center for Criminal Anthropology at the University of Texas at San Marcos.

Westcott's area of ​​interest is the study of the structure of the skull. With the help of computed tomography, he analyzes the microscopic structures of the bones of corpses. He works alongside entomologists and microbiologists, including Zhavan (who, in turn, examines soil samples taken from the experimental site in San Marcos where the corpses lie), computer engineers, and the operator who controls the drone - with his using aerial photographs of the site.

"I read an article about drones being used to study agricultural land to see which ones are the most fertile. Their cameras operate in near-infrared, which shows that soils rich in organic compounds are darker in color than others. “I thought that since such a technology exists, then perhaps it can be useful for us too - to look for these little brown spots,” he says.

rich soil

The "brown spots" that the scientist is talking about are the areas where the corpses decomposed. A rotting body essentially changes chemical composition the soil on which it lies, and these changes may be noticeable over the next few years. The pouring out of liquefied tissues from dead remains enriches the soil with nutrients, and the migration of larvae transfers much of the body's energy to its surroundings.

Over time, as a result of this whole process, a "decomposition island" appears - a zone with a high concentration of rich organic matter soil. In addition to the nutrient compounds released into the ecosystem from the cadaver, there are also dead insects, scavenger dung, and so on.

Image copyright getty Image caption Drone cameras operate in the near-infrared range, which, scientists believe, will help to find places where the corpses lay.

According to some estimates, the human body is 50-75% water, and each kilogram of dry body weight during decomposition releases 32 grams of nitrogen, 10 grams of phosphorus, four grams of potassium and one gram of magnesium into the environment. At first, this kills the vegetation below and around, perhaps due to nitrogen toxicity or due to antibiotics contained in the body, which release insect larvae into the soil that eat the corpse. Ultimately, however, decomposition has a beneficial effect on the local ecosystem.

The biomass of microbes on the island of decomposition of the corpse is significantly higher than in the surrounding area. Roundworms, attracted by the released nutrients, begin to multiply in this area, and its flora also becomes richer. Further research on exactly how rotting cadavers change the ecology around them may help to more effectively locate murder victims whose bodies were buried in shallow graves.

Another possible clue to establishing exact date death can give an analysis of the soil from the grave. A 2008 study of the biochemical changes occurring in a cadaveric decomposition island showed that the concentration of phospholipids in the fluid flowing from the body reaches its maximum at about 40 days after death, and nitrogen and extracted phosphorus - after 72 and 100 days, respectively. As we study these processes in more detail, perhaps in the future we will be able to determine exactly when the body was placed in a hidden grave by analyzing the biochemistry of the soil from the burial.

We all will die. But what will happen to your body after that? This is how it will live after you yourself have already passed away.

Life goes on

You are dead when your brain has irreversibly stopped functioning. In any case, according to the definition fixed in Swedish law. But some parts of the body still continue to live. The body does not die at all in one moment, as many believe. Experts distinguish between individual death and cell death.

Strange sounds

For example, heart valves can be used up to 36 hours after death, and the cornea continues to function twice as long.

A lot of strange things can also happen, for example, the bodies of the dead make strange sounds, people continue to think, and dead men have erections. Let's take a look at some of the things that can happen to your body from 30 seconds to 50 years after you die.

30 seconds

Brain cells are sensitive to lack of oxygen and are among the first to decompose. However, some nerve cells can survive so long that scientists aren't quite sure if you're still perceiving something even though you're already dead.

The dead keep on thinking

Studies have shown that brain activity can be in the region of zero for more than a minute and thus indicate that a person is dead, and then rise to a level that can be compared to full wakefulness, only to then fall back to zero. What happens in this case is still not entirely clear.

According to some assumptions, the brain is reawakened to life because the soul leaves the body. From a scientific point of view, this phenomenon is explained by the fact that a large number of nerve cells emit impulses one last time.

Scientists are speculating whether this might explain why people who have been brought back to life after cardiac arrest report light and strong feelings. In this case, they could be conscious even after their heart stopped beating, and they could retain thoughts and feelings even when brain activity was close to zero for a while.

No one knows

This phenomenon has also led to discussions about whether transplant surgeons should wait for a possible surge in activity before proceeding with the operation.

“It is unlikely that a person is conscious during such brain activity. But the only ones who actually come close to this and can at least say something about it are those who experienced a state of near death, ”says brain researcher Lars Olsson (Lars Olsson) from the Karolinska Institute.

12 hours

After 12-18 hours, cadaveric spots reach their maximum coverage. They arise from the sedimentation of the blood. They can, for example, show whether the corpse has been moved, which, for example, forensic doctors pay attention to when a crime is being investigated.

24 hours

Macrophages are another type of long-lived cells. They are related to the immune system. It was possible to trace that they can work even a day after you died, for example, destroying soot in the lungs after a fire.

36 hours

Even though your heart has stopped beating, heart valves can be well preserved because they have connective tissue cells that live long. Heart valves can be used for transplantation up to 36 hours after a person dies.

72 hours

The cornea also continues to live. It can be used within three days after you died. This is due, among other things, to the fact that the cornea is very close to the surface, in direct contact with air and receiving oxygen from it.

96 hours

When the body begins to decompose, gases are formed. They can cause strange and unpleasant sounds like groans and stifled cries. It happened that this phenomenon was very frightening to people who even thought that the dead man came to life.

After a few days, dirty green spots appear on the body. Often they begin to spread from the stomach - due to bacteria. Well, then spread throughout the body.

Erection occurs

Even though this is very unlikely, cases have also been reported of dead men having erections. This is because blood can collect into clots that still contain nutrients and oxygen.

The blood provides nourishment to cells that are susceptible to calcium. Certain muscles are activated by calcium, and in men this can cause a certain muscle to contract and lead to an erection.

Growing hair and nails

Henrik Druid, a forensic physician and legal scholar, performed about 6,000 autopsies. According to him, many believe that hair and nails continue to grow after a person has died. But this is a delusion.

“The skin loses fluid, shrinks and tightens. It looks like the nails and hair are protruding more than before. But the fact that they are growing is an illusion.”

Fluid outflow

After a couple of weeks, dead bodies are usually already badly damaged.

“Then one can see traces of strong decomposition. For example, the body turns brownish-green in color, fluid-filled blisters develop on the skin that may burst, and fluid may leak from the mouth and nostrils, including from tissues and muscles.

In addition, corpses often swell and emit unpleasant odors. At this point, stiffness stops, and the body becomes very soft: the skin, muscles and organs have already decomposed in order. When the body no longer has immunity, the bacteria in it freely multiply, feed and destroy it.

And if you also had some kind of infection, and you already died with harmful bacteria inside, or you had cancer, then the body will decompose even faster.”

Laying of larvae

How quickly the decomposition process will take place also depends on the environment. If the body lies warm, it decomposes faster than if it were cool. A body left in nature is generally destroyed within a month, after it has been taken over by bacteria and insects. In a coffin, the body usually lasts much longer.

“But sometimes the flies have time to lay their faces, including in the openings of the body - the eyes, nose, mouth and anus - before the body hits the ground. This can happen in a matter of days. Then they will go to the coffin with the body and continue to decompose it.”

dug up again

After a year, as a rule, the bodies lying in the ground are completely eaten by bacteria, and only bones remain after them. But there are exceptions. One example is the well-known case from the Swedish city of Arboga, when the body was dug up a year after burial, and it could still be opened.

“It depends on the conditions. For example, it matters how wet or dry it was in the ground and the coffin. Bacteria thrive in a humid environment."

Soap consistency

In water, the body can persist much longer than in the ground, which was confirmed, among other things, during the rise from the bottom of the steamer Freja in 1994. The ship sank 98 years earlier, and yet the bodies were identified.

In the water in the body, the formation of the so-called fat wax occurs, due to which it becomes hard and acquires a soapy consistency, which is unfavorable for bacteria.

As for the skeletons, it is estimated that they should rot in the grave for a period of fifty years. But here, too, things can vary greatly. It happened that the bones were preserved for hundreds of thousands of years.

The decomposition of a corpse is a continuous process that can take from several weeks to several years, depending on the environment. On this site, we have divided the process into stages, which are characterized by certain physical properties corpse. To illustrate the decomposition process, we use a piglet as a model. For, the distribution of fat in a pig is very similar to that of a human. And attracts insects no less. These factors make the pig the best example of how the human body decays. These are newborn piglets (weighing about 1.5 kg) that are accidentally crushed by their mothers - a key cause of piglet death. Their bodies were donated to science Please note - this gallery contains nasty graphics and descriptions.. So, all stages of the decomposition of the corpse.

1. Stage of decomposition: live pig. Live pigs do not externally decompose, but their intestines contain a variety of bacteria, protozoa and nematodes. Some of these microorganisms are ready for a new life. When pigs die, they lose their ability to keep them under control.

2. Stage of decomposition: from 0 to 3 days. Although the body looks fresh from the outside shortly after death, the bacteria that ate the contents of the intestine before death begin to digest the intestine itself. They eventually burst out of the intestines and begin to digest the surrounding internal organs. The body's own digestive enzymes (usually in the intestines) have also spread throughout the body, contributing to its decomposition.
Enzymes inside individual cells are released when the cell dies. These enzymes break down the cell and its connections with other cells.

Insect activity.
From the moment of death, flies are attracted to organs. Without the normal protection of live animals, blowflies and common flies are able to lay their eggs around wounds and natural body openings (mouth, nose, eyes, anus, genitals). The eggs hatch into larvae and enter the body within 24 hours. The life cycle of a fly from egg to larva takes two to three weeks. This may take significantly longer at low temperatures.

3. Decomposition stage: 4 to 10 days. The pig became bloated from the accumulation of gases in the body. Bacteria destroy tissues and cells, releasing fluids in body cavities. They often breathe in the absence of oxygen (anaerobically) and produce a variety of gases including hydrogen sulfide, methane, cadaverine, and putrescine as by-products. People find these gases unpleasant to smell, but they are very attractive to various insects.
The accumulation of gases as a result of the intensive activity of multiplying bacteria creates pressure inside the body. This pressure inflates the body and increases the amount of fluid from the cells and blood vessels into the body cavity.

Insect activity.

4. Decomposition stage: 10 to 20 days. The bloated body eventually collapses, leaving behind a flattened body whose meat has a creamy consistency. The exposed parts of the body are black and there is a very strong odor of decay.
A large volume of fluid in the body flows out of the body, this stage and seep into the surrounding soil. Other insects and mites feed on this material.

Insects consume most of the flesh and body temperature increases. Bacterial decay continues and the bacteria will eventually consume the leftover flesh if the insects are not present.

Insect activity.

5. Decomposition stage: 20 to 50 days(oil fermentation). The pig is now very flat and starting to dry out. All other flesh is removed during this period and the body dries up. It has a cheesy smell caused by butyric acid, and this smell attracts a new set of cadaveric organisms.
The surface of the body that is in contact with the ground becomes moldy.

Insect activity.

6. Degradation stage: 50 to 365 days (dry decomposition). From the pig, only bones and hair remain. The body is now dry and decays very slowly. Eventually all the hair disappears, leaving only the bones.

Insect activity.

What remains are those organisms that can feed on the hair including moths and microorganisms such as bacteria. Ticks, in turn, feed on these microorganisms.

They remain on the body for as long as traces of hair remain obvious. Decomposition time depends on the amount of hair a particular look wears. Humans and pigs have comparatively little hair and this stage of decomposition is much shorter than in other species.