Corpse changes. Forensic medical examination of corpses: lecture Early cadaveric phenomena and their forensic medical significance

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The timing of death, determined by the nature of changes in cadaveric spots - 1998.

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The timing of death, determined by the nature of changes in cadaveric spots - 1998.

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— 1998.

Analysis of the results of mathematical processing showed that the experimental data reject the hypothesis about the distribution of dynamometry data according to the normal law. Therefore, a specific digital gradation of dynamometry indicators for the corresponding intervals of the postmortem period as an independent diagnostic test in forensic medical practice is unacceptable.

Podolyako V.P. Diagnostic capabilities of dynamometry indicators when deciding the issue of how long ago death occurred “Forensic medical examination.” –M., –1998, 1. –p. 3–6.

Stages of formation of cadaveric spots

1. Stage hypostasis continues for 12 hours after death. The liquid part of the blood is in the vessels and when pressure is applied to the spots, the blood is squeezed out of the vessels, and after the pressure stops, it quickly fills them again. This leads to the disappearance of cadaveric spots when pressure is applied, as well as to their movement to the underlying sections when the body position changes.
2. Stage stasis(diffusion) is observed after 12 hours from the moment of death and lasts up to 24 hours. Cadaveric spots turn pale, but do not disappear when pressed. This is due to the fact that the liquid part of the blood, stretching the wall of the vessel, begins to seep into the tissue. In parallel with this, hemolysis of red blood cells occurs. At this stage, the spots do not move when the position of the corpse changes, but somewhat reduce their intensity.
3. Stage imbibition develops on the second day after death. Cadaveric spots are well fixed, do not move, and do not turn pale when pressed, since the soft tissues are saturated with blood.

The time for restoration of the original color of cadaveric spots after pressure with a dynamometer, depending on the duration of death (according to N.P. Turovets, 1962)

Time to restore the original color of cadaveric spots depending on the duration of death (according to A.I. Mukhanov, 1968)

Time to restore the color of cadaveric spots (in seconds) after dosed pressure on them (according to V.I. Kononenko, 1971) 1

During dosed dynamometry of cadaveric spots, the research conditions are strictly standardized. The surface area of ​​the dynamometer in contact with the skin of the cadaveric spot is 1 cm 2. Pressure is applied with a force of 2 kgf/cm 2 for 3 s. The dynamometer should be positioned perpendicular to the surface of the skin. When cadaveric spots are localized on the posterior surface of the body, pressure is applied in the lumbar region along the midline, and when cadaveric spots are located on the anterior surface of the body, pressure is applied along the midline of the sternum body. The time for color restoration of cadaveric spots is recorded using a stopwatch. Under these conditions, as the author (V.I. Kononenko) notes, the accuracy of determining the duration of death does not exceed ±2–4 hours.

The timing of death, determined by the nature of changes in cadaveric spots (Jaklinski, Kobiela, 1972).

Time to restore the original color of cadaveric spots depending on the stage and duration of death (according to Yu.L. Melnikov and V.V. Zharov, 1978)

Dynamometry indicators in the sacral region with the corpse in the supine position (according to V.P. Podolyako, 1998) 2

Dynamometry indicators in the forehead and sternum when the corpse is positioned face down (according to V.P. Podolyako, 1998) 2

Literature

1. Kononenko V.I. Complex physical and chemical study of cadaveric spots (forensic medical assessment of the dynamics of their development): abstract of thesis. dis. ... dr. - Kharkov, 1971.
2. Diagnostic capabilities of dynamometry indicators when resolving the issue of how long ago death occurred / Podolyako V.P. // "Forensic-medical examination". - M., 1998. - No. 1. - P. 3-6.

Cadaveric spots

Cadaveric spots.

Corpse spots(hypostatici, livores cadaverici, vibices) are perhaps the most famous sign of the onset of biological death. They belong to early cadaveric phenomena, and are, as a rule, areas of skin of a bluish-violet color. Cadaveric spots arise due to the fact that after the cessation of cardiac activity and loss of tone of the vascular wall, passive movement of blood occurs through the vessels under the influence of gravity and its concentration in the underlying areas of the body.

Time of occurrence

The first cadaveric spots appear after 1-2 hours in case of acute death, in agonal death - 3-4 hours after the onset of biological death, in the form of pale areas of skin coloring. Corpse spots reach their maximum color intensity by the end of the first half of the day. During the first 10-12 hours, there is a slow redistribution of blood in the corpse under the influence of gravity. Cadaveric spots can be mistaken for bruises, and vice versa. An incision protects against such an error: in case of bruising, coagulated blood appears, but if staining occurs only from hypostasis, then, depending on the time elapsed after death, they find either only simple hyperemia, or saturation of the corresponding tissues with blood serum.

Characteristic color

Since cadaveric spots are blood visible through soft tissues and skin, the color of cadaveric spots depends on the cause of death.

• In asphyxial death, cadaveric spots have an intense bluish-violet color, like all the blood of a corpse, supersaturated with carbon dioxide.
• In carbon monoxide poisoning, carboxyhemoglobin is formed, which gives the blood a bright red color, and cadaveric spots acquire a distinct reddish-pink tint. They acquire the same color for a while if a corpse is transferred from a warm room to a cold one or vice versa.
• In case of cyanide poisoning, cadaveric spots have a cherry color.
• In cases of death from hypothermia and drowning in water, cadaveric spots with a pinkish-red tint.
• In cases of poisoning with methemoglobin-forming poisons (nitrates, nitrites, Berthollet salt, methylene blue and others) and at certain stages of decay, cadaveric spots have a gray-brownish tint.
• In case of death from massive blood loss, 60-70% of blood is lost during life, cadaveric spots are weakly expressed, never cover the entire lower surface of the corpse, have the appearance of islands delimited from each other, are pale, and appear at a later date.

Stages of development

In agonal death, the timing of the appearance and intensity of coloring of cadaveric spots are determined by the duration of the terminal period. The longer the terminal period, the later the cadaveric spots appear and have a paler color. This phenomenon is due to the fact that during agonal death the blood in the corpse is in a state of varying degrees of coagulation, while during acute death the blood is liquid. In the development of cadaveric spots, depending on the timing of occurrence, three phases are distinguished.

1. Hypostasis stage- is the initial stage of development of a cadaveric spot, begins immediately after the cessation of active blood circulation and ends after 12 - 14 hours. At this stage, cadaveric spots disappear when pressed. When the position of the corpse changes (turns over), the spots can completely move to the underlying sections.
2. Stage of stasis or diffusion- cadaveric spots begin to transform into it approximately 12 hours after the onset of biological death. At this stage, gradual thickening of the blood in the vessels occurs due to the diffusion of plasma through the vascular wall into the surrounding tissue. In this regard, when pressed, the cadaveric spot turns pale, but does not completely disappear, and after some time it restores its color. When the corpse's position changes (turns over), the spots may partially move to the underlying sections.
3. Stage of hemolysis or imbibition- develops approximately 48 hours after the moment of biological death. When pressing on the cadaveric spot, there is no change in color, and when turning the corpse over, there is no change in localization. In the future, cadaveric spots do not undergo any transformations other than putrefactive changes.

Meaning and methods of assessment

• cadaveric spots are a reliable, earliest sign of death;
• they reflect the position of the body and its possible changes after death;
• allow you to approximately determine the time of death;
• the degree of severity reflects the speed of death;
• the color of cadaveric spots serves as a diagnostic sign for some poisonings or may indicate the conditions in which the corpse was located;
• they allow us to talk about the nature of the objects on which the corpse was located (brushwood, folds of linen, etc.).

Significance in ascertaining the fact of the occurrence of biological death

The forensic medical significance of cadaveric spots lies not only in the fact that they can be used to determine the duration of death. Their main significance is that they are a reliable sign of death: none of the intravital processes can imitate cadaveric spots. The appearance of cadaveric spots indicates that the heart stopped working at least 1 - 1.5 hours ago, and, as a result, irreversible changes have already occurred in the brain as a result of hypoxia.

Significance in determining the duration of death

The nature of the change in the cadaveric spot when pressed allows forensic experts to roughly establish the duration of death. When analyzing the behavior of a cadaveric spot, it is necessary to take into account the cause of death, the rate of its onset (acute or agonal), and the research methodology. Fairly approximate results can be obtained by applying finger pressure on the spot, so standard methods with a dosed area and pressure force have been developed. Pressure is carried out using a standard calibrated dynamometer. The author of the method, V.I. Kononenko, based on the research conducted, proposed tables for determining the duration of death based on the results of dynamometry of cadaveric spots. The error of the method, according to the author, is within ±2 - ±4 hours. The lack of indication of the confidence interval of the error is a significant drawback of the technique, which reduces its significance for practical application.

In folklore

• From the protocol from the scene of the incident: “Corpse spots the size of 10 and 20 kopeck coins were found on the murdered person, with a total area of ​​three rubles and twenty kopecks.”
• From a letter to Kashpirovsky: “Dear doctor, after your sessions, my cadaveric spots disappeared and the suture from the autopsy dissolved.”

Notes

Links

Wikimedia Foundation. 2010.

Encyclopedic Dictionary F.A. Brockhaus and I.A. Ephron Wikipedia

Clinical death continues from the moment the cardiac activity, breathing and functioning of the central nervous system ceases and until irreversible pathological changes develop in the brain. In a state of clinical death, anaerobic metabolism in tissues continues due to the reserves accumulated in the cells. As soon as these reserves in the nervous tissue run out, it dies. In the complete absence of oxygen in the tissues, the death of cells in the cerebral cortex and cerebellum (the most sensitive parts of the brain to oxygen starvation) begins within 2-2.5 minutes. After the death of the cortex, restoration of the vital functions of the body becomes impossible, that is, clinical death turns into biological death.

In the case of successful active resuscitation measures, the duration of clinical death is usually taken to be the time elapsed from the moment of cardiac arrest to the start of resuscitation (since modern methods of resuscitation, such as maintaining the minimum required blood pressure, blood purification, artificial ventilation, exchange transfusion or donor artificial blood circulation, allow you to maintain the life of nervous tissue for quite a long time).

Under normal conditions, the duration of clinical death is no more than 5-6 minutes. The duration of clinical death is influenced by the cause of death, conditions, duration, age of the dying person, the degree of his excitement, body temperature at the time of dying and other factors. In some cases, clinical death can last up to half an hour, for example, when drowning in cold water, when, due to low temperature, metabolic processes in the body, including the brain, slow down significantly. With the help of prophylactic artificial hypothermia, the duration of clinical death can be increased to 2 hours. On the other hand, some circumstances can greatly shorten the duration of clinical death, for example, in the case of dying from severe blood loss, pathological changes in the nervous tissue that make it impossible to restore life can develop even before cardiac arrest.

Clinical death is, in principle, reversible - modern resuscitation technology makes it possible in some cases to restore the functioning of vital organs, after which the central nervous system “turns on” and consciousness returns. However, in reality, the number of people who have experienced clinical death without serious consequences is small: after clinical death in a medical hospital, about 4-6% of patients survive and fully recover, another 3-4% survive, but suffer severe disorders of higher nervous activity, the rest die . In some cases, with a late start of resuscitation measures or their ineffectiveness due to the severity of the patient’s condition, the patient may switch to the so-called “vegetative life”. In this case, it is necessary to distinguish between two states: the state of complete decortication and the state of brain death.

Biological death is a necrotic process in all tissues, starting with the neurons of the cerebral cortex, the necrosis of which occurs within 1 hour after the cessation of blood circulation, and then within 2 hours the death of cells of all internal organs occurs.

The fact of the occurrence of biological death can be established by a doctor or paramedic based on the presence of reliable signs, and before their formation, based on the combination of the following symptoms:

Absence of cardiac activity (no pulse in large arteries; heart sounds cannot be heard, no bioelectrical activity of the heart);

The time of absence of cardiac activity is reliably more than 25 minutes (at normal ambient temperature);

Lack of spontaneous breathing;

Maximum dilation of the pupils and their lack of reaction to light;

Absence of corneal reflex;

The presence of postmortem hypostasis in sloping parts of the body.

With some intracerebral pathology, as well as after resuscitation measures, a situation sometimes arises when the functions of the central nervous system, primarily the cerebral cortex, are completely and irreversibly lost, while cardiac activity is preserved, blood pressure is preserved or maintained by vasopressors, and breathing is provided by mechanical ventilation. This condition is called brain death (“brain death”).

The diagnosis of brain death is very difficult to make. There are the following criteria:

Complete and persistent lack of consciousness;

Persistent lack of spontaneous breathing;

Disappearance of any reactions to external stimuli and any types of reflexes;

Atony of all muscles;

Disappearance of thermoregulation;

Complete and persistent absence of spontaneous and evoked electrical activity of the brain (according to the encephalogram).

The diagnosis of brain death has implications for organ transplantation. Once it has been identified, organs can be removed for transplantation into recipients.

In such cases, when making a diagnosis, it is additionally necessary to:

Angiography of cerebral vessels, which indicates the absence of blood flow or its level below critical;

Conclusions of specialists: a neuropathologist, resuscitator, forensic medical expert, as well as an official representative of the hospital, confirming brain death.

According to the legislation existing in most countries, “brain death” is equated to biological death.

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Introduction

Chapter 1. The Dying Process

Conclusion

Introduction

Forensic medicine is a branch of medicine that resolves medical and biological issues that arise during the activities of forensic investigative bodies, and also assists health authorities in improving the quality of their work. Forensic medicine is not a random, mechanical collection of medical disciplines used for targeted legal practice, as it was at the beginning of the development of forensic medicine.

Currently, forensic medicine is an independent medical science that studies a certain range of issues and has its own research methods. As forensic medicine developed, a number of sciences emerged from it as independent disciplines, for example, forensic chemistry, forensic psychiatry, and forensic toxicology. Forensic medicine is connected with all other medical sciences, these are pathological physiology, pharmacology, surgery, histology, traumatology. How medical science uses laboratory research methods, X-ray, microbiological, and physiotechnical research methods. With the help of the latter, for example, the type of weapon, the mechanism of injury, and the establishment of the intravital origin of the injury are determined.

Among the legal sciences, criminology is very close to forensic medicine, which is a legal discipline that studies the tactics, methods and techniques of crime investigation. In order to successfully conduct an investigation or trial, and correctly evaluate an expert’s opinion, a lawyer must have an understanding of the capabilities of forensic medicine and the limits of the competence of forensic medical examination. Under this condition, he will be able to correctly select the right experts, formulate questions for the experts, and critically evaluate their conclusions. Often, the investigator himself has to examine the corpse at the scene of the incident, and having knowledge of the basics of forensic medicine, the investigator will be able to navigate in determining how long ago the death occurred, the nature of the injuries, and the features of the incident.

The system of the subject is determined by the existing practice of forensic medical examination and can be presented in the following form: the parocessual part, which sets out the rules for conducting a forensic medical examination, provides the content and interpretation of various laws, regulations, instructions relating to forensic medical examination; the material part, which sets out medical and natural scientific information that makes up the content of forensic medicine as a science. This part is divided into several sections:

1. Department of the doctrine of death (Thanatology) - includes the doctrine of death, its occurrence, its signs, post-mortem changes on the corpse, the difference between violent death and death causing suspicion of violence. This also includes techniques for forensic medical examination of corpses.

2. Department of injuries (forensic traumatology): - includes the study of various injuries, their recognition and precise characteristics, determination of their effect on the body, clarification of the methods and circumstances of injury and their legal assessment.

3. Department of poisoning (forensic toxicology) - poisonings that are important in forensic medicine are studied, as well as their clinical recognition, treatment and prevention.

4. Department of controversial sexual conditions - includes questions regarding sexual functions, determination of infection with sexually transmitted diseases, all types of research regarding violations of sexual integrity (rape, molestation), determination of the child's identity.

5. Pregnancy and childbirth (forensic obstetrics) - studies ways to recognize pregnancy, its duration, recognition of births that have taken place, methods of abortion. This section also includes a chapter on infanticide.

6. Department of forensic medical examination of material evidence - studies biological evidence: blood, semen, hair and interpretation of its results.

7. Border areas of criminology and forensic medicine - forensic technical examination - these are methods of personal identification, feigned and artificial diseases, and determination of the type of death.

8. Department for the study of medical practice and other types of medical work, medical errors and medical practice.

9. The department for the study of mental state (forensic psychiatry) is developed by psychiatrists, studying methods for determining sanity, various mental illnesses that exclude or mitigate criminal liability or interfere with a person’s civil capacity.

There are two main tasks of forensic medicine:

1. Assistance to the justice authorities.

2. Providing medical and preventive care to the population. In accordance with the order of the USSR Minister of Health N166 dated April 10, 1962, it requires forensic medical examiners to: discuss forensic cases at clinical and anatomical conferences, notify health authorities about facts of gross discrepancies in clinical and anatomical diagnoses and defects in medical work; carrying out analyzes of cases of sudden death, transport injuries, domestic and industrial poisoning, in order to carry out preventive measures and identify defects in medical care.

Chapter 1. The Dying Process

The science that studies the issues of death and dying is called thanatology (from the Greek death - thanos). The dying process can be quick or it can be long. There are several periods in the dying process.

1. Preagonal state: weak, rapid pulse, pale or spotted skin, shallow, rapid breathing. During this period, the body tries to turn on compensatory mechanisms aimed at maintaining and normalizing basic life functions. The preagonal state can last for several hours, even if no medical treatment is provided.

2. Agonal state: the beginning of agony (not in all types of dying) is very clearly registered by a terminal pause. It is characterized by the fact that after rapid breathing, it suddenly stops completely. The pause lasts up to 2 - 4 minutes. Following this, agony begins directly, including a single shallow breath, the amplitude of respiratory movements increases, the person seems to gasp for air. Due to a violation of the respiratory act, breathing stops completely. The cerebral cortex turns off, although at the supomolecular level the processes of life are mobilized and continue. The appearance of the dying person changes sharply: the face becomes pale, sallow, the nose is pointed, the cornea loses its luster, and the mouth opens slightly.

3. Clinical death: begins from the moment the activity of the cerebral cortex, breathing, and blood circulation ceases and lasts 4 - 7 minutes, during which resuscitation measures are most often carried out. Determining the fact of death is the most important moment in the work of a forensic doctor, and even more important in the work of the attending physician. It is not difficult to determine the fact of death 6 - 8 hours after its occurrence, when obvious cadaveric phenomena appear. It is difficult to navigate the first 1 - 2 hours. In a hospital setting, this issue is not difficult to resolve since there is a variety of equipment, however, in accordance with the existing situation, the corpses of persons who died in the hospital are transferred to the morgue no earlier than 2 hours after death, that is, no earlier than absolute signs of death appear on the corpse - cadaveric spots. Currently, to ascertain death, indicative and reliable signs of death are used. Orienting factors include: motionless body position, pale skin, lack of consciousness, breathing, pulse, heartbeat, lack of sensitivity to painful stimuli, lack of pupillary reaction to light. When working at the scene of an incident, a forensic expert most often does not have doubts about the fact of death, since by this time the absolute signs of death are clearly visible: the presence of cadaveric spots and rigor mortis, a decrease in body temperature below + 20 degrees, drying of the sclera and cornea, a sign Beloglazova (change in the shape of the pupil when pressed - cat's eye).

Chapter 2. Early cadaveric changes

Cadaveric phenomena are divided into early (on the 1st day after death) and late (become noticeable from the 2nd day). The early ones include:

1. Cooling.

2. Drying.

3. Cadaveric spots.

4. Rigor mortis.

5. Autolysis.

1. Cooling of the corpse - for diagnosing the duration of death, it has only approximate knowledge, since, along with other factors, it is not yet known what the body temperature was at the moment of dying, and it can fluctuate within significant limits not only in patients, but also in healthy people .

Heat production in the body of the deceased stops and the corpse cools down to ambient temperature. The temperature of the corpse may be lower than the ambient temperature due to the evaporation of moisture. The process is usually completed by the end of the first day. Exposed areas (hands, face) cool faster, their cooling can be noticed after 1 - 2 hours, the armpit is slower. It is recommended to measure temperature in the rectum and deep thermometry (liver) using an electric thermometer with special needle sensors.

Heat transfer depends on external conditions: air temperature, humidity, ventilation, clothing and its nature. Individual characteristics also matter: the development of subcutaneous fat (possessing low thermal conductivity, it slows down cooling), age (faster in children), cause of death (faster in case of alcohol or arsenic poisoning, blood loss accelerates), so the results of thermometry have very relative values .

After death occurs, the process of establishing a thermal balance between the temperature of the dead body and the ambient temperature occurs. For example, if the ambient temperature is higher than the temperature of the dead body, then the corpse heats up; if it is lower, the corpse cools down. The greater the temperature difference between the corpse and the environment, the more intense the cooling (or heating) process. The process of changing the body temperature of a corpse is influenced by the following factors: age, physique, position (posture) of the body, the nature and amount of clothing, cause of death, air movement, humidity and other factors. It is generally accepted that at an ambient temperature of 18 °C, a corpse cools down by 1 °C per hour, and by the end of the day it reaches ambient temperature.

At the present stage, the study of the process of cooling a corpse is the most objective way to establish the duration of death.

Devices based on the ETM-ZB electric thermometer make it possible to measure the temperature in the body of a corpse with an accuracy of hundredths of a degree. It is necessary not only to accurately measure the temperature in the body of a corpse, but also to establish the dynamics of its change within 1-3 hours. The best results are obtained by so-called deep thermometry, for example, inserting a flexible temperature sensor into the esophagus to the level of the diaphragm, as well as studying the temperature in the liver tissue. Measuring the temperature in the rectum gives satisfactory results. For more complete reliability, it is necessary to carry out measurements repeatedly at time intervals.

2. Corpse desiccation. The process of drying of the skin (exposed areas of the body) and mucous membranes (cornea of ​​the eyes, mucous membrane of the mouth, mucous membrane of the labia minora) is observed immediately after death and depends, first of all, on environmental conditions. The intensity of the drying process increases sharply under conditions of elevated temperature. When the eyes are open, the cornea in the shape of a triangle (Larche's spots) dries out and becomes cloudy; the border of the lips of the mouth is dense to the touch and dark red in color. The mucous membrane of the protruding tip of the tongue becomes dense to the touch and red-brown in color during mechanical asphyxia. The skin of the scrotum (or the mucous membrane of the labia minora) may also dry out in the absence of underwear; it becomes dense to the touch and red-brown in color. In areas of the skin, especially in thin places (hands) that have been subjected to compression, areas of drying out can be found, which give the impression of intravital abrasions or bruises. To establish the survival of these formations, it is necessary to place a gauze napkin soaked in water for 2 - 3 hours. After soaking in water, such an area of ​​parchment density turns pale and disappears, while intravital damage remains almost unchanged.

Drying flutters due to the evaporation of moisture from the surface of the body. Evaporation of moisture is a physiological, constantly compensated process that occurs in a living organism. After death, the physiological balance between loss and replenishment of fluid is disrupted, and the body begins to lose moisture through condensation and evaporation.

In places that are most moist during life (lips, sclera), drying is intense and is presented in the form of areas of parchment density. The speed and intensity are influenced by environmental conditions - air temperature, air movement and individual characteristics - degree of nutrition, dehydration, clothing.

Drying of the skin and mucous membranes begins immediately after death, but visually manifests itself after a few hours. It begins with the corneas of open or slightly open eyes (Larchet's spots - drying out in the shape of a triangle 4 - 5 hours after death). The epidermis protects the skin from drying out, so where it is damaged, conditions for drying are created (abrasions, furrows). The lack of a direct relationship between the rate of drying and the period after death, as well as many influencing factors, prevent its use for diagnosing the duration of death.

3. Cadaveric spots - after the cessation of cardiac activity, blood flows under the influence of gravity to the lower parts of the body. Vessels that have lost their tone dilate and fill with blood. Corpse spots appear after 2 - 3 hours.

After death, blood and lymph move under the influence of gravity to the lower parts of the body and organs. The blood vessels in these sections passively expand under fluid pressure. And after 1 - 2 hours, the blood-filled vessels of the skin and subcutaneous fat give the skin first a light purple color, and then a dark purple color, that is, a cadaveric spot is formed. The skin of the body in the overlying parts of the corpse becomes pale due to the movement of blood.

In the formation of cadaveric spots, 3 stages can be distinguished: hypostasis, stasis and imbibition.

1. Hypostasis. Cadaveric spots form immediately after cardiac arrest, the most intensive development occurs in the first hours (2 - 4 hours). When the position of the corpse changes during these hours, blood moves from the places of primary formation of cadaveric spots and the appearance of new ones on other, lower lying parts of the body. In areas of the body of a corpse that are pressed to the plane (interscapular, lumbar and gluteal regions, the back of the thigh and lower leg), cadaveric spots do not form due to compression of the blood vessels containing blood. Due to this mechanism, the pattern of clothing folds is also clearly visible against the background of the formed cadaveric spots. The color and severity of cadaveric spots are influenced by the following factors: cause of death, type of death, duration of dying, condition and amount of blood in the body, and others. As a rule, cadaveric spots have a dark purple color, but when poisoned by various compounds, their color may change. In case of poisoning with carbon monoxide or hydrocyanic acid compounds, the blood becomes bright red and due to this, the cadaveric spots have a red-pink color. When poisoned by poisons (aniline dyes, nitrobenzene and others), cadaveric spots become grayish-brown, and when poisoned by hemolytic poisons (arsenic compounds, many types of fungi, and others), cadaveric spots have a jaundiced tint. When the body contains a small amount of blood, as a rule, with heavy blood loss or when the blood in the vessels is in a state of coagulation, cadaveric spots turn out to be weakly expressed and are presented in the form of local or merging areas.

2. Stasis. Blood hemolysis products gradually diffuse through the vascular wall into the surrounding tissue. Compression of blood vessels over time causes the effect of blanching of the cadaveric spot to a lesser extent. The movement of the body of a corpse and its turning over 6 - 18 hours after death reveals an important forensic circumstance: the cadaveric spots that formed initially and ended up in the overlying sections during the turning over do not completely disappear, and the degree of their blanching decreases over time. New cadaveric spots appear on the underlying areas of the corpse. Their intensity is less, the later the corpse was turned over. After 12 - 15 hours, the plasma sweats, hemolysis products permeate the tissues, the blood thickens, so the cadaveric spots turn pale when pressed and partially move.

3. Imbibition. After the first day, when the corpse is turned over, the cadaveric spots where they formed previously do not disappear and do not form in new places. This principle is the basis for one of the methods for establishing the age of formation of cadaveric spots and, thereby, determining the age of death. To do this, a specially designed dynamometer is used to apply pressure with a force of 2 kilograms per 1 square centimeter with an exposure of 3 s to the area of ​​the cadaveric spot, and then determine the time for restoration of the color of the blanched area to the level of color intensity of the surrounding skin. After 24 - 35 hours, red blood cells disintegrate and the surrounding tissues become saturated with plasma containing hemoglobin. They do not fade or disappear. Cadaveric spots depend on the condition of the blood: liquid blood - cadaveric spots are abundant, anemia - weakly expressed.

4. Muscle rigor. The forensic medical significance of muscle rigor is extremely great, since it helps to fix the body posture at the time of death.

This term was first proposed in 1990. V.N. Kryukov, before this the term “rigor mortis” was widely used, which did not reflect the essence of the processes taking place. The formation of muscle rigor is influenced by the following factors: individual characteristics of the body, environmental conditions, cause of death and mechanism of dying.

After death, passive movements in the joints of the limbs are easily achieved due to sharp relaxation of the muscles. But by the end of 1-2 hours after death, the skeletal muscles gradually become dense to the touch due to the contraction of muscle tissue due to its death, that is, muscle rigor develops. This process occurs in all muscles simultaneously, but ends at different times depending on the characteristics of the structure and blood supply. Since physiologically the extensors are stronger than the flexors, when examining the corpse it can be stated that the fingers are slightly bent or even bent into a fist, the arms are bent at the wrists and elbow joints, and the legs are at the knees. The muscles gradually become more dense to the touch, and at the height of the development of rigor mortis, there is no passive movement in the joints of the limbs.

If muscle rigor is disturbed during the first 24 hours, it develops again, but to a much smaller extent. Resolution of muscle rigor begins by the end of the third day, free passive movement appears in the joints of the limbs.

There is another type of muscle rigor - thermal muscle rigor. It is associated with protein coagulation in skeletal muscles, which occurs at temperatures above 50 °C. Thermal rigor rigor can also occur in cases where normal rigor rigor has already resolved and the corpse was exposed to high temperature, for example in a fire.

Based on the fact that the process of muscle death occurs slowly, under the influence of electrical stimuli it actively responds with its contraction. The duration of the response to an electrical stimulus varies for different muscles: for facial muscles - up to 2 - 5 hours, for the quadriceps femoris muscle - up to 12 - 18 hours. When examining a corpse at the scene of an accident, experts use specially designed portable devices to determine the level of electrical irritability of muscles to determine how long ago death occurred.

During the first hours after death, as a result of impact with a hard blunt object in the area of ​​the biceps brachii muscle, it is possible to obtain an idiomuscular tumor due to local contraction of the striated muscles at the site of damage. The extent of the tumor can provide additional information about the time of death.

Rigor (muscle) rigor - muscle contraction in a living person occurs as a result of the interaction of muscle protein with ATP, which is then broken down releasing a large amount of energy. This energy is used for mechanical muscle work. Relaxation is associated with the resynthesis of ATP from ADP in the presence of oxygen. In the muscles of a corpse, ATP breakdown and muscle contraction gradually occur, and because there is no oxygen, resitis does not occur and the muscles do not relax.

Rigor mortis is intense in case of poisoning with strychnine, cicutotoxin, acids, and so on; weakly - hemolytic poisons, drugs, and so on. With asphyxia - faster due to convulsions. At high temperatures it develops and resolves faster, because biochemical reactions occur with the absorption of heat.

Rigor mortis develops after 3 - 4 hours, after 8 - 14 hours all muscles are in a state of rigor mortis. Allowed after 2 - 3 days.

Descending development and resolution. Rigor mortis, broken 10-12 hours after death, is not restored.

5. Autolysis - the property of biological objects to hydrolytically decompose their own structures under the action of enzymes. After death occurs, enzyme production continues for some time in individual organs and tissues. The active activity of enzymes (pepsin, trypsin, and so on) does not always stop immediately after death, and cells also disintegrate, and enzymes that are normally isolated from tissues are released. Tissue acidosis promotes increased enzyme activity.

Initially, autolysis manifests itself in organs with a high content of proteolytic enzymes (pancreas, adrenal glands, stomach, spleen, liver). There is a softening and liquefaction of organs and tissues, a violation of their structure.

Autolysis has a negative meaning, simulating intravital pathological processes. In addition, it allows you to determine the rate of dying (more pronounced with rapid death).

Conclusion

Death is the natural end of life. In medical practice, the period of death is counted from the moment of final cardiac arrest and death of the cerebral cortex. But at the same time, it is known that damage to the cerebral cortex (5-8 minutes after cardiac arrest) does not at all mean the death of the entire organism. Many organs and tissues survive the moment of cardiac arrest for quite a long time and can be used in transplantation (kidneys, cartilage tissue, heart, liver, bone marrow, skin and other organs).

The first stage of dying is the preagonal state, the second is the terminal pause, then the atonal period begins, then clinical and biological death.

The time period for transition from life to death for different types of injuries is not the same. In case of injuries that are accompanied by a violation of the integrity of vital internal organs (brain, heart, spinal cord), as well as with various types of asphyxia, death occurs in a short period of time, calculated from several seconds to several minutes. In forensic medical practice, this type of death is called “acute.”

As a rule, the onset of “acute” death is usually associated with primary respiratory arrest. During external and internal examination of the corpse in such cases, abundant cadaveric spots of a diffuse nature are found, occupying more than 0.5 of the entire surface of the body, ecchymosis (punctate hemorrhages) in the mucous membrane of the eyelids, cerebral edema, congestion of the internal organs, dark liquid blood in the cavities of the heart and large vessels, acute pulmonary emphysema with foci of edema, swelling of the gall bladder bed.

If the moment of cardiac arrest is preceded by an atonal period, which can last from several tens of minutes to several hours, then the resulting disorder of blood circulation leads to congestion. When examining a corpse in such cases, they find abundant, diffuse cadaveric spots, relaxation of the sphincters, pronounced swelling of the tissue of the lungs and membranes of the brain, congestive venous congestion of the internal organs, in the cavities of the heart and large vessels, dark red and yellow blood clots (fibrin).

Depending on the cause in forensic medicine, it is customary to distinguish the category, type and type of death.

Violent death means premature death, which occurred from the consequences of various influences of environmental factors (mechanical, electrical, chemical, etc.).

The type of death should be understood as a set of factors that caused the death of a person under their influence. Death can occur as a result of poisoning, extreme temperatures, hypoxic conditions arising from external causes (drowning, hanging, etc.). These types of deaths are considered under the category of violent deaths. In the category of non-violent death, the type of death is sudden death.

In forensic medicine, the type of sudden death means death that occurs as a result of hidden or even asymptomatic diseases, in the midst of visible, apparent health. Such a death is unexpected for others and raises suspicion of a violent death (for example, poisoning).

In the category of violent death, the type of death means murder (taking the life of one person by another), suicide (taking the life of oneself) or death due to a combination of unfavorable, unforeseen circumstances - an accident.

The responsibility of a forensic medical expert is only to establish the category and type of death, and establishing the type of death is the prerogative of the forensic investigative authorities, since the doctor does not have special (medical) methods for establishing the intent of the act.

The first step of a medical examiner when examining a body at a crime scene is to determine whether there are signs of life or the absence thereof. To do this, the doctor uses orienting signs of death, which include the absence of reflexes from the cornea and pupils, the absence of breathing, heartbeat, and pulse in large blood vessels.

If there are signs of life in the victim, the doctor must begin resuscitation measures and, with the help of the investigative authorities, organize the evacuation of the victim to the nearest medical facility, while he himself remains to continue examining the scene of the incident.

To ascertain death when examining a body at the scene of an incident, the doctor uses, in addition to orienting signs, reliable signs of death that develop in the corpse in connection with the onset of biological death and the development of post-mortem changes in the corpse.

Bibliography

1. Textbook "Forensic Medicine" ed. prof. Tomilina.

2. Forensic medicine" Smolyaninov (for medical universities).

3. Directory for lawyers "Forensic medical examination" Prof. Tomilin V.V.

4. Course of lectures on Forensic Medicine" by Prof. Gromov.

5. Vinogradov “Forensic Medicine” (for lawyers) M: 1991

6. A.A. Solokhin “Qualification tests in forensic medicine” M: 1994,

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The study of cadaveric phenomena allows us to solve a number of very important questions that clarify the circumstances of death, namely: when death occurred, whether the initial position of the corpse changed. Certain options for the development of post-mortem processes on a corpse can provide preliminary information about the causes of death.

Post-mortem processes developing on a corpse, according to their biological essence, can be divided into three large groups.

1. Early cadaveric phenomena are processes caused by the cessation of life support processes for organs and tissues: ϶ᴛᴏ cadaveric spots, rigor mortis, cadaveric cooling, cadaveric drying out and autolysis.

2. The phenomena of tissue survival are the responses of dying tissues to external stimuli - electrical, mechanical and chemical. The more time passes from the moment of death, the less these reactions will last.

3. Late cadaveric phenomena - changes in the corpse that occur after early cadaveric phenomena have completed their development, including: rotting, mummification, skeletonization, fat wax, peat tanning. These processes are closely related to damage to corpses by animals and plants.

The appearance and development of cadaveric phenomena is influenced by many external and internal factors. Knowledge of their influence on the processes of post-mortem changes in a corpse is necessary, since without such knowledge it is almost impossible to use the dynamics of post-mortem processes to solve forensic and, at the same time, investigative problems.

The main internal factors of this plan will be: the degree of fatness, age, the presence of serious chronic or acute diseases, the degree of alcoholization of the body and some others. These processes are significantly influenced by the cause of death and accompanying phenomena, such as blood loss, duration and severity of the agonal period, etc. The nature of clothing matters. External conditions that influence the development of post-mortem processes include ambient temperature, humidity, and the development of flora and fauna of the environment.

The nature and degree of influence of the factors listed above will be presented when describing specific post-mortem processes.

Early cadaveric phenomena.

Cadaveric spots are areas of body tissue posthumously soaked in blood. Outwardly, they look like large area bruises. The color of cadaveric spots, violet-bluish or purple-blue, depends on many reasons, primarily on the color of the blood and its quantity.

Immediately after death, the skin of a human corpse is pale, perhaps with a slight grayish tint. Immediately after death, body tissues still consume oxygen from the blood, and therefore all blood in the circulatory system acquires the character of venous. Cadaveric spots are formed due to the fact that after circulatory arrest, the blood contained in the circulatory system, under the influence of gravity, gradually descends into the underlying parts of the body, overflowing mainly the venous part of the bloodstream. Blood shining through the skin gives it a characteristic color.

To solve the issues of how long ago death occurred, the movement of the corpse, and others regarding cadaveric spots, it is extremely important to understand the processes of development of cadaveric spots. Cadaveric spots in their development go through three stages: hypostasis, diffusion and imbibition.

Hypostasis is the stage at which blood descends into the underlying parts of the body, filling their vascular bed. This stage begins immediately after circulatory arrest, and the first signs of coloration of the skin can be observed within 30 minutes, if there was no blood loss and the blood in the corpse is liquid. Clearly cadaveric spots will remain 2–4 hours after death.

To determine the stage of development of cadaveric spots, the following technique is used: press on the cadaveric spot, if at the point of pressure the cadaveric spot completely disappears or at least turns pale, then measure the time after which the original color is restored. The fact of a change (non-change) in the color of the cadaveric spot and the time of its recovery are the criteria by which the stage of development of cadaveric spots and, ultimately, the time of death are determined.

Cadaveric spots in the stage of hypostasis completely disappear when pressed due to the fact that the blood only fills the vessels and easily moves through them. After the pressure stops, blood fills the vessels again after some time, and the cadaveric spots are completely restored. When the position of the corpse changes in the ϶ᴛᴏth stage of development of cadaveric spots, they completely move to new places, depending on which parts of the body have become underlying. The hypostasis stage lasts on average 12–14 hours.

The diffusion stage is the next stage in the formation of cadaveric spots; it is also called the stasis stage. As a rule, pronounced manifestations characteristic of the ϶ᴛᴏth stage are noted 12 hours after death. In this stage, the overstretched walls of blood vessels become more permeable, and an exchange of fluids begins through them, which is uncharacteristic of a living organism.

Lymph and intercellular fluid gradually penetrate through the walls of blood vessels into them and mix with the blood, they contribute to hemolysis (disintegration, dissolution) of red blood cells. The liquid part of the blood also penetrates the walls of blood vessels and permeates the surrounding tissues. As a result of these processes, the blood thickens. In the diffusion stage, when pressure is applied to cadaveric spots, they do not disappear completely, but become exceptionally pale, and after some time they restore their original color.

It is worth saying that the full development of the ϶ᴛᴏth stage occurs in the period from 12 to 24 hours.

When the position of the corpse changes during this period of time, the cadaveric spots partially move to those parts of the body that become underlying, and partially remain in the old place due to the saturation of the tissues surrounding the vessels. Previously formed spots become somewhat lighter than they were before the corpse was moved.

The imbibition stage is the third stage of development of cadaveric spots. During this period, a mixture of lymph and intercellular fluid leaked from blood vessels permeates the skin, subcutaneous fat and other body tissues in the underlying sections. This process of tissue saturation with blood begins already at the end of the first day after death and ends completely after 24–36 hours from the moment of death. When you press on a cadaveric spot that is in the stage of imbibition, it does not turn pale. Based on all of the above, we come to the conclusion that if more than a day has passed since the death of a person, then when such a corpse is moved, the cadaveric spots do not change its location.

The division of the process of changing cadaveric spots into stages is quite arbitrary, since these phases do not have clear boundaries, especially at the borderline moments of time around 12 and 24 hours after death, when processes characteristic of both the previous phase and the subsequent one occur simultaneously.

As mentioned above, a variety of information can be obtained from cadaveric spots. In particular, the unusual color of cadaveric spots may indicate the cause of death. If a person died with significant blood loss, the cadaveric spots will be very faint. When dying from carbon monoxide poisoning, they are bright, red due to the large amount of carboxyhemoglobin; when exposed to cyanide, they are cherry red; when poisoning with methemoglobin-forming poisons, such as nitrites, cadaveric spots have a grayish-brown color. On corpses in water or a damp place, the epidermis loosens, oxygen penetrates through it and combines with hemoglobin, which causes the pinkish-red tint of corpse spots along their periphery.

Changes similar to those that occur at the surface of the skin also occur in the internal organs; these changes are studied during the opening of body cavities and internal organs. Do not forget that it will be important to say that cadaveric spots in the head area, especially the scalp, can be mistaken for a hematoma.

Sometimes, against the background of cadaveric spots, post-mortem hemorrhages, called ecchymosis by doctors, can be found. Externally, they look like rounded areas, slightly protruding above the surface of the skin, measuring up to 5x5 mm, and usually appear 5-6 hours after death. It is worth noting that they are more typical for the corpses of young people who died from drowning in water, from hanging in a noose, from alcohol poisoning, etc. They should not be confused with intravital hemorrhages.

In those places where the skin of the corpse was in close contact with hard protruding areas of the surface on which it was located, the relief of the surface is clearly visible in the form of whitish areas of skin not soaked in blood. In the practice of forensic medicine, there are cases when, based on such patterns on cadaveric spots, the surface on which the corpse was located at the time of the formation of cadaveric spots was identified.

As noted above, one of the main methods for studying cadaveric spots will be the method of applying pressure to the cadaveric spot. Pressure is usually applied in the interscapular or lumbar areas, 2–3 cm from the midline. If a corpse is found in a position other than on the back, the most underlying areas of the cadaveric spots are examined. The pressure is produced by a special dynamometer, and in its absence, by the palmar surface of the nail phalanx of the index finger. At ϶ᴛᴏm the pressure force should be 2 kg per 1 sq. cm, pressure duration 3 seconds. It is extremely important to strictly observe these conditions, since failure to comply will lead to an error in the calculations. The time of restoration of the color of the cadaveric spot is recorded using a stopwatch. After pressing on the cadaveric spot, it is extremely important to turn the corpse so that the place of pressure takes its original position, i.e. one in which a cadaveric spot was formed.

Assessing cadaveric spots over time, taking into account external and internal conditions affecting the development of this post-mortem phenomenon, allows us to solve a number of forensic issues.

1. Cadaveric spots are an unconditional sign of death. The presence of cadaveric spots indicates that the person is dead and not in some state such as lethargic sleep, coma, etc.

2. Cadaveric spots indicate the position of the corpse after death and a change in this position.

3. The dynamics of the development of cadaveric spots is one of the post-mortem processes that makes it possible to judge the time of death.

4. The degree of severity of cadaveric spots gives grounds to judge the speed of death (the duration of the agonal period)

5. The color of cadaveric spots in some cases allows us to judge the possible cause of death, as well as the conditions under which the corpse was found after death.

Rigor mortis. Rigor mortis is usually called the condition of the muscles of a corpse, in which they become denser and fix parts of the corpse in a certain position. A numb dead body seems to become stiff.

Immediately after death, all the muscles of the human body relax, lose their natural elasticity during life, the face takes on a calm appearance, this is probably where the word deceased comes from.

The process of rigor mortis develops simultaneously in all skeletal and smooth muscle muscles. But its manifestation occurs in stages: first in small muscles - on the face, neck, hands and feet, then rigor becomes noticeable in large muscles and muscle groups. Pronounced signs of rigor are observed 2–4 hours after death. Rigor mortis increases within 10–12 hours from the moment of death. For about 12 more hours, rigor remains at the same level. Then it starts to disappear. Forensic scientists use the term resolution of rigor mortis to refer to the process of gradual disappearance of rigor mortis in the muscles of a corpse.

Rigor mortis is assessed by forensic doctors during external examination at the place where the corpse was found and in the morgue. The assessment is made using a three-point system (weak, moderate, good) sequentially in each muscle group. The principle of uneven manifestation of rigor mortis in large, medium and small muscles is the basis for determining the duration of death by rigor mortis.

Rigor mortis can be resolved (destroyed) artificially, by applying physical effort (for example, bending and unbending a frozen limb). If rigor mortis is affected in this way within 8–10 hours from the moment of death, then rigor mortis will be partially restored within further in the disturbed muscles. In cases where rigor mortis is exposed after this period of time, it does not recover. By the way, this pattern is used to resolve the issue of the possible movement of a corpse.

Rigor mortis develops not only in skeletal muscles, but also in the smooth muscles of internal organs. As a result, certain post-mortem processes occur in the internal organs, which must be taken into account when examining corpses. Immediately after stopping, the heart is in a relaxed state, then, as muscle rigor increases, its muscles tense, especially in those parts where it is more pronounced, for example, in the left ventricle, blood is squeezed out of the cavities of the heart under the influence of contracting muscles. With painful changes in the myocardium, the heart muscles almost do not stiffen. Post-mortem changes associated with the formation of rigor mortis also occur in other internal organs.

The process of development of rigor mortis is significantly influenced by various external and internal factors. At elevated ambient temperatures (above +25° C), rigor mortis develops faster, but at lower temperatures the process slows down. Rigor rigor grows faster in dry air, and slower in humid air. In persons with developed muscles, rigor mortis grows faster and reaches greater severity, and, conversely, in children, old people, exhausted and sick people, the cadaveric phenomenon forms slowly and is less pronounced. Rigor mortis develops more strongly with injuries and burns, large loss of blood, diseases of cholera, tetanus, and epilepsy. All these factors are extremely important to take into account to avoid erroneous conclusions based on the results of a rigor mortis study. These factors have the opposite effect on the resolution of rigor mortis. For example, at low temperatures, rigor develops more slowly, but also lasts longer; at elevated temperatures, it forms faster, but also resolves faster.

A muscle condition similar to rigor occurs when a corpse is exposed to elevated temperatures (more than 50°–60° C). In muscles exposed to heat, proteins, and with them muscle fibers, contract, which leads to muscle tension. And since the flexor muscle groups are more powerful than the extensor ones, the corpse as a whole takes on a characteristic pose, called the boxer’s pose.

The study of muscle rigor during an external examination of a corpse at the place of its discovery and in the morgue allows one to obtain information for solving the following important problems.

1. Rigor mortis is a reliable sign of death.

2. The dynamics of development and resolution of rigor mortis makes it possible to resolve the issue of how long ago death occurred.

3. Sometimes the dying posture of a corpse, preserved by rigor mortis, makes it possible to judge the position of a person’s body at the time of death and suggest the cause of death.

Cooling the corpse. Normally, in a living person, the body temperature, measured in the armpit, ranges from +36.4° to +36.9° C. In the internal organs and tissues of the body, the temperature is 0.3–0.5 degrees higher. Constant temperature is ensured by thermoregulation processes. These processes stop after the regulatory activity of the central nervous system stops, and the temperature begins to decrease, trying to equalize the ambient temperature. It should be remembered that the body temperature at the time of death of a person can be higher than the specified norm by 1°, 2° and even 3° C due to infectious diseases, poisoning, overheating of the body and similar processes. Excluding the above, according to some researchers, the temperature of a corpse can increase immediately after death by 1°–3° C. According to literary data, increased body temperature of corpses in the first hour after death is observed in approximately 15% of cases.

Naturally, the rate of cooling of a corpse depends on many external and internal factors. First of all, it depends on the ambient temperature. The lower it is, the more intense the cooling of the corpse. If the ambient temperature is higher than body temperature, the corpse will not cool down at all. Air humidity also affects the cooling process; in a damp, cold environment, cooling is more intense. It is important to know that the availability and condition of clothing plays a big role. Do not forget that the temperature, thermal conductivity and heat capacity of the substance on the surface of which the corpse is located are important. Ventilation of the room, exposure to direct sunlight, etc. play a role.

Of the internal factors, the most important are: fatness (development of subcutaneous fat), massiveness and size, age (children's corpses and the corpses of elderly people cool down faster). People who are exhausted and weakened by the disease, who have lost a lot of blood, lose their temperature more intensely after death.

It must be remembered that when a person is in sub-zero temperatures, the surface parts of the body can be significantly cooled, “icy” to the touch, while the temperature inside the person’s body will be quite high.

Based on all of the above, we come to the conclusion that by studying the process of cooling a corpse, we can obtain useful information for solving a number of issues.

1. A decrease in body temperature in the rectum below +20° C is a reliable sign of death.

2. By changing the temperature of the corpse, you can determine the duration of death.

3. If an elevated temperature is detected in a corpse in the first hour after death, assumptions can be made about certain circumstances preceding death.

Corpse desiccation. Immediately after death, the process of cadaveric desiccation begins. From the most moistened and unprotected areas of the body surface, liquid evaporation begins, which leads to drying and thickening of the tissue, these areas of the tissue darken. Such areas of the body will be those in which the epidermis is damaged - the surface layer of the skin, as well as the surfaces of the mucous membranes exposed to the external environment, areas of transition from the mucous membranes to the skin, areas of loose epidermis, areas of the epidermis affected by certain skin pathologies. Specifically: the first to dry out on a corpse are the intravital and postmortem injuries, the eyeballs, the scrotum and head of the penis in men, the labia in women, the area of ​​the red border of the lips, the tip of the tongue protruding from the mouth, and later the tip of the nose, ears, fingertips and etc.

The time characteristics of the appearance of drying out depend primarily on the temperature of the air surrounding the corpse and humidity. Under normal room conditions, drying becomes noticeable after 2–3 hours on the corneas and whites of the eyes, if they are open. Drying of the corneas looks like clouding; such changes are called “Larchet spots.” After 6–12 hours, the exposed areas of the eyeballs become yellowish-gray.

In windy, dry weather, outdoors, the first signs of clouding of the corneas of open eyes are observed within an hour after death.

In cold conditions, the process of drying out the corpses of newborns occurs very quickly. According to some authors, up to 100 grams of liquid per day can evaporate from such a corpse, which can be very noticeable on a small body.

Areas of the epidermis damaged postmortem (so-called parchment spots), as well as areas around the red border of the lips, areas of pathologically altered epidermis after drying can have a reddish-brown color, thereby simulating intravital damage. However, upon careful examination of such areas of the skin, differences are easily detected.

The process of drying a corpse can continue until almost complete evaporation of moisture from it; in this case, they speak of mummification of the corpse. This phenomenon will be discussed below.

Signs of cadaveric desiccation are analyzed by forensic scientists to determine the time of death, as well as for other purposes.

Cadaveric autolysis. Cadaveric autolysis, like previous posthumous changes, is considered by most authors to be an early cadaveric phenomenon; some assess this phenomenon as a supravital reaction. The essence of the process is essentially that disorganized tissue enzymes after death continue their impact on surrounding structures, destroying them to one degree or another. Signs of enzyme exposure are found mainly during autopsy. Based on them, as well as on other cadaveric phenomena, the question of how long ago death occurred is decided.

Phenomena of tissue experience.

The second group of phenomena studied on a corpse in order to determine the duration of death is phenomena associated with the survival of individual tissues of the body. After the death of the organism as a whole, individual tissues are still capable of exhibiting functions. It is worth saying that to determine the time of death, they use the ability of these tissues to react in response to a particular irritation. In particular, muscles contract in response to electrical or mechanical stimulation, and some tissues react to chemicals. It must be remembered that such tissue reactions are called supravital.

Muscle response to electrical stimulation. If needle electrodes are inserted into the opposite ends of any muscle of a corpse, for example the biceps, and voltage is applied, then the fresh corpse will experience a contraction of this muscle to one degree or another. The force of contraction is assessed on a three-point scale. A strong contraction is observed up to 2–2.5 hours after death, an average contraction up to 2–4 hours, and a weak contraction up to 4–6 hours after death. The technique requires compliance with certain conditions: the use of a current of a certain voltage and strength. The good thing about the technique is that the influence of external conditions on its results is insignificant.

Muscle response to mechanical stress. When struck by a hard object with a limited striking surface, for example, a metal stick, a swelling is formed on a muscle (say, the biceps) of a fresh corpse, which is called an “ideomuscular tumor.” The presence of such a muscle reaction to mechanical impact indicates that a short time has passed since death. Visually, such a reaction can be detected within a period of up to 6 hours from the moment of death. In the period from 6 to 11 hours, the reaction can only be detected by feeling (palpating) the site of impact. At a later date, the reaction to the impact will be negative, which will be reflected in the formation of an indentation at the site of the impact. External conditions and the cause of death do not have a significant impact on this reaction.

On fresh corpses, the muscles respond to mechanical stimulation of the tendons. When a tendon is struck, the contracting muscles contract. It looks similar to how neurologists test tendon reflexes in patients by tapping the knees and Achilles tendons. It is worth saying that a positive reaction to tapping on all tendons indicates that no more than 1.5–2 hours have passed since death. If only some muscles reacted positively, then about 6–8 hours passed.

The reaction of the pupils to the administration of atropine and pilocarpine. After death occurs, under the influence of internal biomechanisms, the pupils of the eyes dilate, then narrow for about 2 hours, then dilate again.

The pupils react to the administration of atropine and pilocarpine (as well as some other chemicals), dilating or contracting, and the strength of the reaction is inversely proportional to the time of death, which is used to determine the time of death. In the period up to 11 hours after death, a double reaction is observed, namely, from the injection of atropine, the pupil dilates, and after the injection of pilocarpine it narrows. A separate reaction (narrowing or expansion) is detected on average up to 24 hours from the moment of death. After 24 hours, the pupils do not respond to the administration of atropine and pilocarpine.

Late cadaveric changes.

In addition to the early cadaveric changes and tissue survival phenomena described in the previous section, a number of processes develop on the corpse, which differ from the first two groups in their later appearance, which is why they were called late cadaveric phenomena.

Late cadaveric phenomena include: rotting, mummification, skeletonization, fat wax, peat tanning, as well as damage to corpses by animals and plants.

In general, all late cadaveric phenomena are characterized by a strong dependence on the conditions of the corpse’s location and a large scatter in the time characteristics of their occurrence, which significantly complicates their use for solving forensic medical issues.

All late cadaveric phenomena, to a certain extent, can be divided into two groups: the first is destructive, the second is preservative. On one corpse, different cadaveric phenomena can simultaneously develop, for example, mummification and rotting, if parts of the corpse are in different conditions.

Rotting. Rotting belongs to the group of destructive cadaveric phenomena. It is worth noting that it develops as a result of exposure to microorganisms on the tissues of a corpse. Under their influence, tissues are destroyed into simpler biochemical and chemical components. As a result of the formation of substances such as ammonia, hydrogen sulfide, methyl mercaptan, data mercaptan and some others, there will be a characteristic putrid-cadaverous odor.

Putrefactive bacteria will be common inhabitants of the human intestine.
It is interesting to note that there they (during human life) are in balance with other microorganisms and vital processes of the body, perform their functions and, under normal conditions, do not go beyond the boundaries of their distribution areas. After the death of a person, everything changes: many types of putrefactive bacteria begin to uncontrollably multiply and spread in the human body, which leads to decay of the corpse.

Initially, putrefaction develops most strongly in the large intestine, and is accompanied by the formation of a large amount of gases, which accumulate in the abdomen. Intestinal bloating can be noted as early as 6–12 hours after a person’s death. Then there will be signs of decay in the form of a dirty green color, first in the right iliac region, then in the left. This coloring occurs due to the formation of sulfhemoglobin from blood hemoglobin and released hydrogen sulfide. Under room conditions, putrefactive staining will remain in the iliac areas on the anterior abdominal wall by the end of the second day. The rot then spreads through the blood vessels, mainly veins, to other areas of the body. This process is accompanied by the appearance of the so-called putrefactive venous network - a clearly visible dirty green pattern of veins. Signs of a putrefactive venous network are observed 3–4 days after death.

Also, on the 3rd–4th day of the development of putrefaction, an increase in the accumulation of putrefactive gases in the subcutaneous fatty tissue and other tissues is noted. Due to this, swelling of the corpse occurs, the so-called putrefactive emphysema. Body parts increase sharply in size: abdomen, chest, limbs, neck, nose, lips, in men - the scrotum and penis, in women - mammary glands. Bloody discharge is observed from the natural orifices of the body; this should be differentiated from the manifestation of injury. After 4–5 days, blisters filled with a foul-smelling reddish-brown putrid liquid will appear on the surface of the skin due to its delamination. Partially exfoliated epidermis can be displaced due to mechanical action, and when this occurs, the reddish dermis, the underlying layer of skin, becomes visible. It must be remembered that such manifestations of rotting imitate skin burns. On days 6–10, the epidermis completely peels off and can be easily removed along with nails and hair. Subsequently, through the damaged areas of the skin, the accumulated and newly released putrefactive gases leave the corpse, the size of the corpse and its parts decreases. The processes of decay soften and disorganize the tissues - the so-called putrefactive melting of the corpse occurs. As a result, bones are exposed in places, especially in those places where they are covered with a small amount of soft tissue. It is worth saying that complete putrefactive decay of the soft tissues of a corpse (skin, fatty tissue, muscles, certain components of internal organs, etc.) under conditions suitable for decay can occur in 3–4 weeks. After this period, bones, ligaments, cartilage, and formations consisting of a large amount of connective tissue are preserved.

A corpse in a state of significant putrefactive changes is a very unpleasant sight. The presence of putrefactive tissue destruction, their greenish-dirty color, and fetid odor create the basis for a negative assessment of the possibilities of productive forensic research of such corpses. Let us note that it seems that it is impossible to establish the cause of death, the mechanism of its occurrence and resolve other issues regarding such a corpse. However, this is not always the case. On putrefactively altered corpses, it is possible to detect and determine damage, traces of imposition, and certain well-defined pathological processes, for example, cardiosclerosis, atherosclerosis, etc. Therefore, any degree of putrefactive decomposition of a corpse will not be a basis for refusing to prescribe and conduct a forensic medical examination of the corpse .

Skeletonization. In the absence of natural and artificially created processes preserving the corpse, such as mummification, fat wax, peat tanning, exposure to salt solutions, freezing, etc., the process of decay turns into the process of skeletonization. The essence of this post-mortem phenomenon is essentially that through putrefactive melting and as a result of eating the tissues of the corpse by insects, the soft tissues of the corpse completely disappear from the bone base. Clearly visible signs of skeletonization can be noted on the corpse after 1 month of the corpse being in ϲᴏᴏᴛʙᴇᴛϲᴛʙ conditions. Almost complete skeletonization (only bones, ligaments and cartilage remain) can occur in 3–6 months, and after a year the skeleton disintegrates into individual bones, as most of the ligamentous apparatus is destroyed.

Conditions that accelerate the decay process naturally accelerate the skeletonization process. In this case, the greatest importance for the complete cleansing of skeletal bones from soft tissues is the presence of a large number of insects and other types of animal carrion eaters, complementing and replacing each other in the destruction of the soft tissues of the corpse.

Of the insects in this regard, the most active are flies and beetles of several species. Rodents, in particular rats, destroy the soft tissues of a corpse at the initial stage of decay and even before its signs appear. Parts of the corpse can be chewed by wolves, jackals, cats and dogs. There have been cases of birds damaging corpses. The intense impact of animals on a corpse accelerates its skeletonization.

In an aquatic environment, a corpse can be actively eaten by aquatic animals, primarily various crustaceans, as well as fish.

Plants growing in Russian latitudes usually do not have a significant effect on the corpse. The corpse exhibits only the development of certain types of mold, and when the corpse is in the open ground, certain plants can grow through it. The study of plants in the bed of a corpse sometimes makes it possible to determine how long ago it was located at the place of discovery.

Under certain conditions where a corpse is located, its tissues are subject to the preservative influence of environmental factors.

Mummification. Mummification is the process of post-mortem changes in the tissues of a corpse, during which moisture almost completely evaporates from them. During this process, tissues become denser and decrease in volume; the weight of a completely mummified corpse is no more than one tenth of the original one.

For the development of mummification, a number of conditions are necessary, in particular: good ventilation of the location of the corpse; high temperature, although mummification can also take place at room temperature under conditions of very good ventilation and dry air; low air humidity. Under the most favorable conditions, complete mummification of a human corpse of average build can occur in 4–6 months, while the average time for complete mummification is indicated by different authors within 6–12 months. Partial mummification can be detected on corpses after 1–2 months. The corpses of children and people with a low content of subcutaneous fat mummify faster than others.

Mummified corpses in ϲᴏᴏᴛʙᴇᴛϲᴛʙcan be preserved for an indefinitely long time without undergoing changes, therefore determining the age of death from a corpse whose mummification has ended is extremely difficult.

It should be noted that forensic medical examination of mummified corpses makes it possible to resolve a number of issues related to the occurrence of death. In particular, dried corpses retain signs of damage, traces of imposition, and some traces of painful changes in organs and tissues. Therefore, such corpses can and should be carefully examined.

Fat wax. Fat wax is a cadaveric change that is associated with late cadaveric phenomena of the preservative type, its second name is saponification. The main conditions for the formation of fat wax will be high humidity in the environment where the corpse is located and minimal air access. Saponification develops in water, in dense and moist soils and in other similar conditions.

The essence of the process is the gradual decomposition of the fat contained in the corpse and the washing out of some of the derivatives formed during this process. The remaining water-insoluble fatty acids combine with alkali and alkaline earth metal salts, forming a substance called fat wax. Depending on which metal salts the fatty acids are combined with, the fat wax can be either a gelatinous substance of a dirty gray color or a dense substance of gray-white color with a greasy sheen.

Various authors indicate that they observed the first signs of saponification of the tissues of a corpse from 25 days to 3 months after death. It is worth saying that complete saponification of a corpse occurs no earlier than 6–12 months on the corpses of adults; on the corpses of children, perhaps a little faster.

The study of saponification processes only tentatively allows us to speak about the duration of death.

Peat tanning. Peat tanning is a preserving late corpse phenomenon, the essence of which is the tanning (compaction) of tissues under the influence of an acidic environment. In forensic medical practice, corpses that have undergone such a change are even less common than corpses in a fat wax state. Mostly such finds were made in peat bogs, where body tissues of deceased people were exposed to long-term exposure to humic acids. Under the influence of these acids, the skin of corpses and internal organs become denser and acquire a dark color. Under the influence of acids, calcium is washed out of the bones and they become soft and flexible. Peat-tanned corpses last a very long time. It is possible to detect and study damage on such corpses.

Various authors have included several more post-mortem processes in the group of preservative cadaveric changes. Salting of corpses is a phenomenon in which the corpse is exposed to concentrated solutions of salts or salt in dry form, through which they stop the processes that destroy the corpse. There are literary data indicating the possibility of preserving corpses when they get into oil. Formalin, certain alcohols and other chemicals have a preservative effect on biological tissues. Low temperature is one of the factors that can preserve corpses unchanged for a long time. The corpses of prehistoric animals are known to have been preserved to this day in permafrost.

The conditions under which the corpse is located from the moment of death until the moment of its examination may change. And then, instead of some post-mortem processes, others begin to develop. In practice, there are common cases when different conditions simultaneously act on a corpse and, consequently, its different parts change in different ways. For example, a corpse located on the soil, from the ground side, rots and is destroyed by corpse-eating insects, and at this time the parts of the body facing upward are mummified due to ventilation and drying.

If a corpse with signs of beginning rotting ends up in a dry, well-ventilated place, the rotting processes are suspended and mummification develops.
It is worth noting that the decay process stops when the ambient temperature drops below 0° C. Conversely, a corpse preserved in some way, for example, frozen in the cold season, can begin to rot and be destroyed by animals when it warms up.