Significance of postmortem phenomena: 1, determining death 2, estimating time of death 3, inferring cause of death 4, body spasm 5, suggesting whether the body has been moved 6. Some phenomena after death are easily confused with changes before death. According to the sequence of postmortem phenomena, it is divided into: 1 according to the sequence of postmortem phenomena, it is divided into: early postmortem phenomena: it refers to the early postmortem phenomena issued within 24 hours after death. Changes in the birth of a corpse. Include excessive biological reaction, muscle relaxation, corneal opacity, excessive biological reaction, muscle relaxation, corneal opacity, leatheroid, necrophilia, necrophilia, necrophilia, necrophilia, necrophilia, necrophilia, necrophilia, necrophilia, necrophilia, necrophilia, necrophilia, necrophilia, autophagy and autophagy. Family digestion, etc. Post-death phenomenon: refers to the changes that occur within 24 hours after death. 2. Late death: refers to the changes that occur within 24 hours after death. Can also be divided into: change. It can also be divided into: destructive type: including corpse corruption, moldy corpse and white bones; Destruction types: including carrion, moldy corpse and white bone; Preservation types: including mummies, corpse wax, peat tanning and impregnation. Preservation types: including mummies, corpse wax, peat tanning and impregnation. Section 1 Definition of early postmortem phenomenon (1) Supernatural reaction: tissues, cells and some organs of human body formed after somatic death, 1, definition: tissues, cells and some organs of human body formed after somatic death can still maintain a certain life function and respond to stimuli to a certain extent, which is called Supernatural reaction. Become a super-life reaction. 2. Expression of Supergrowth Reaction (1) decapitation reaction (8) Postmortem contraction reaction of vascular smooth muscle (2) Myocardial contraction (9) postmortem delivery (3) Muscle supergrowth reaction (10) (4) Muscle contraction caused by electrical stimulation (10) Sweating reaction of sweat glands (. It is inferred that muscle relaxation (2) After muscle relaxation somatic death, muscle tension disappears and limbs become soft. 1 defines somatic death, muscle tension disappears and limbs become soft, which is called muscle relaxation. Relax your muscles. Forensic significance: Indentation can judge the parking posture after death; 2. Forensic significance: Indentation can judge the parking posture after death, whether to move the body, and when to move the body. And the time to move the body. Parchment-like transformation (III) After parchment-like transformation dies, water quickly evaporates from the thinner part of the skin, 1, which means that after death, water quickly evaporates from the thinner part of the skin, and it dries and hardens locally, showing yellow-brown or dark brown, which is called leather transformation. Dry and hard, yellowish brown or dark brown, called leathery. Under the conditions of dry air, high temperature and fast airflow, leather samples are easy to form under the conditions of dry air, high temperature and fast airflow. It is easy to form leather. 2. Forensic significance: it can make abrasion more obvious; It is easy to be mistaken for forensic significance: it can make bruises more obvious; Damage or corrosive poison. Damage or corrosive poison. Corneal opacification (4) Corneal opacification (corneal opacification) After death, the corneal transparency decreases and becomes turbid, 1. Definition: After death, the cornea becomes opaque, cloudy and grayish white, and finally the pupil can't be seen at all, which is called corneal opacity. 2. The factors affecting corneal opacity include whether the eyelids are closed, the temperature and humidity of the surrounding environment. Including whether the eyelids are closed, the temperature and humidity of the surrounding environment. Forensic significance: estimating the time of death. Mild 6 3, forensic significance: estimated time of death. Mild 6 ~ 12h, moderate 15 ~ 24h, severe 12h, moderate 15 ~ 24h, severe >: 48h (5) After the corpse died, metabolism stopped, 1. Definition: After the death of a corpse, metabolism stops, heat is no longer generated, and heat in the body is constantly emitted. The heat in the body is first conducted to the body surface, and then continuously dissipated through the heat dissipation surface. The heat in the body is first conducted to the body surface, and gradually dissipated due to the convection of the surrounding air, and the temperature of the corpse gradually drops to the ambient temperature, or algor mortis. Forensic autopsy, forensic autopsy, generally measures rectal temperature or liver surface temperature to calculate the time of death. To calculate the time of death. 2. Factors affecting the corpse's cooling Environmental factors: different regions, different seasons, (1) Environmental factors: different regions, different seasons and different times of the day have different temperatures. The temperature is different. Physical factors: body fat, age, cause of death. (2) The factors of the corpse itself: the fatness, age and cause of death of the corpse. (3) Other environmental factors: clothing, cold water, soil, air humidity Other environmental factors: clothing, cold water, soil, air humidity, ventilation. Ventilation. 3. Forensic significance The cold corpse is one of the important bases for inferring the time of death. (1) corpse cold is one of the important evidences to infer the time of death. It was previously believed that when the temperature of the corpse dropped to 20℃, the death was confirmed. Confirmation of death at 20℃ (2) Confirmation of death when the body temperature drops to 20℃. (6) The blood in the blood vessels of the corpse stopped due to circulation, 1. It is defined as that the blood in the blood vessels of a corpse sinks to the lower part of the corpse due to its own weight due to the stop of circulation, so that it sinks to the lower part of the corpse, deposits in the blood vessels of the uncompressed part, and presents unclear colored spots through the skin, which becomes the essence of the corpse). Spots (essence). The development of necrophilia: Generally, necrophilia appeared after death 1 hour. 2. The development of necrophilia: necrophilia began to appear 1 ~ 2 hours after the death of ordinary people. Usually divided into three stages. Usually divided into three stages. The decline period of (1) generally appears in small blocks or stripes 2 hours after death, and in small blocks or stripes 2 hours after death. Fusion in the form of fragments after hours, fusion in the form of fragments at uncompressed parts of the body after 12 hours, fusion in the form of fragments at uncompressed parts of the body after 3-6 hours, and fusion in the form of fragments at uncompressed parts of the body after 6- 12 hours. Purple, the compressed part is pale. Pressing the corpse spot with your hand can subside, and removing your finger can reappear. If you turn the body over and press it with your hand, the corpse spots can disappear, and remove your fingers to reappear. Then the original lividity partially or completely disappears, and the body, then the original lividity partially or completely disappears, and the lividity re-forms in the new lower part. Forming lividity. Cut the skin of the dead point and see blood drops flowing out of the blood vessels. Cut the skin of the dead point and see blood drops flowing out of the blood vessels. It is easy to wipe off with gauze, and it can flow out again after wiping off. It's erased, and it can flow out again after it's erased. (2) In the infiltration stage, most of the dead spots were large dark purple12 24 hours after death; 12 ~ hours, 12 ~ 24 hours after death, and the lividity is mostly deep purple; Shiatsu can't completely subside, turn over the corpse, can't completely subside, turn over the corpse, and it is still possible to form a fuzzy new corpse spot in the new lower part, and the original corpse spot can't completely disappear. Fuzzy new corpse spot, the original corpse spot can not completely disappear. When cutting dead point skin, when cutting dead point skin, squeeze out a small amount of blood from blood vessels by hand, and there may be reddish blood-like liquid in the tissue. Drops, at the same time, there can be reddish blood-like liquid flowing out of the tissue. Tissue dyed red cannot be erased. Red is indelible. (3) 24 hours after death, the necrotic spots were fixed. After 24 hours, after death, the corpse spot is fixed. No matter whether the corpse is directly pressed or turned over, the original corpse spots will not disappear again. Cut the skin and subcutaneous tissue of the corpse spot and turn over the corpse. The original corpse spot will not disappear. The skin and subcutaneous tissue of the corpse spot were cut, and the section was dark purple or purplish red, and no blood dripped out of the blood vessels. The section is dark purple or purplish red, and there is no blood dripping from the blood vessels. 3. The distribution of corpse spots appears in the uncompressed part of the lower body and the uncompressed part of the lower body. When the posture of the corpse is different, the position where the corpse spots appear is different. Now the parts are different. 4, the color of the corpse spot The longer the person dies, the darker the color. The longer the time after death, the darker the color. But it mainly depends on the color of hemoglobin and its derivatives. Depending on the color of hemoglobin and its derivatives. CO poisoning: CO poisoning: cherry red cyanide poisoning: cyanide poisoning: bright red potassium chlorate, nitrite, lead poisoning: potassium chlorate, nitrite, lead poisoning: taupe nitrobenzene poisoning: nitrobenzene poisoning: blue-green 5. Internal factors affecting the death spot: mainly related to the cause of death. (1) Internal cause: mainly related to the cause of death. External cause: the low-position oppressed part is pale; (2) External cause: the low-position oppressed part is pale and the shape of the oppressed object is 6. Visceral congestion can cause postmortem congestion, and the blood volume in the same organ is uneven, uneven, with less upper part and more lower part. There are many places. 7. Forensic significance Lividity is one of the earliest signs of death. (1) Lividity is one of the earliest signs of death. (2) Lividity can be used to infer whether the position of the corpse has changed at the time of death or after death. Whether there is any change. (3) According to the development degree of lividity, the time of death can be roughly inferred. The color of the spots on the body can indicate some kind of poisoning. (4) The color of the corpse spot can indicate some kind of poisoning. The thickness and brightness of the corpse spot can indicate the blood flow and personality of the corpse. (5) The density and lightness of the corpse spots can indicate the blood flow and characteristics of the corpse. Lividity can point out the influence of external environmental conditions on the corpse. (6) Lividity can indicate the influence of external environmental conditions on the corpse. Lividity should be distinguished from subcutaneous hemorrhage. (7) Lividity should be distinguished from subcutaneous hemorrhage. Subcutaneous hemorrhage can occur in any part of the body, with small scope and clear edge, and may be accompanied by exfoliation and local swelling, inflammatory reaction, exfoliation and local swelling, and inflammatory reaction. It won't fade. (7) Rigor and corpse spasm After death, all muscle groups become stiff to fix joints. 1. It is defined that all muscle groups become stiff after death to fix joints, and the body is in a stiff state, which is called rigor mortis (rigidity, rigor mortis). Stiffness). 2. Mechanism of rigor mortis: The mechanism of rigor mortis is related to the exhaustion of ATP in muscle: 3. The time for rigor mortis to occur and relieve is generally 1. Generally, rigor mortis begins to appear at 1 ~ 3 hours after death, and it begins to appear at 4 ~ 6 hours after the body size, and joints can also be detected, and it is the hardest at 24 hours. Joints can also be tested, and the most difficult thing is 24 hours. Hours are the hardest. Within 4 hours after death, the formed rigor mortis was destroyed artificially, and it will not happen again within 4 ~ 6 hours after death for a long time. This phenomenon is also called rigidity. It can happen again for a long time, which is also called fossilization. But the intensity is weaker than the initial rigor mortis. More than 6 hours after death, the damaged rigor mortis is not easy to form again. For the weak. After more than 6 ~ 8 hours of death, the damaged rigor mortis is not easy to form again. 4. The order of rigor mortis formation is divided into ascending type and descending type. There are two types: ascending type and descending type. 5. Factors affecting the occurrence of rigor mortis (1) Individual factors (2) Cause of death (3) Ambient temperature 6. Corpse spasm is a special phenomenon after death. The moment of death is a special phenomenon after death. At the moment of death, the muscles directly enter the stiff state without relaxation, and when they relax, they directly enter the stiff state and maintain the posture and action at the moment of death, which is called corpse spasm. Action, become a corpse spasm (corpse spasm). Most of them are local and systematic. Most of them are local and systematic. 7, myocardial and smooth muscle rigor mortis 8, forensic significance rigor mortis is the confirmation of death. (1) A stiff corpse is a confirmation of death. We can guess the time of death. (2) The time of death can be calculated. It helps to judge the state at the time of death, and the body has been moved. (3) It helps to judge the state at the time of death, and the body has been moved. (8) autolysis and autodigestion 1. Definition: After death, the cellular structure of tissues and cells is destroyed due to various enzymes inherent in cells. Due to various enzymes, the cellular structure is destroyed, which softens and even liquefies organs. This is called autolysis. Liquefaction is called autolysis. 2. Factors affecting autolysis (1) Temperature (3) Differences in organs and tissues (3) Morphological changes of autolysis (4) autodigestion After death, the gastrointestinal wall is dissolved by digestive juice, which is called autodigestion. Family digestion. (2) Death process 5. Forensic Significance (1) According to the development of autolysis, it is obvious that a long time has passed after death. According to the development of autolysis, it is obvious that a long time has passed after death. (2) Distinguish autolysis from pathological changes. The lesion has a life response. Distinguish autolysis from pathological changes. The lesion has a life response. (3) At autopsy, gastrointestinal digestion should not be mistaken for poisoning or other diseases. He is ill. In the second section, the postmortem phenomena in the late postmortem phenomena can be divided into two categories: destructive and preservation. Post-mortem phenomena can be divided into two categories: destructive and preservation. (1) Postmortem phenomenon 1, corpse decay (1) Definition: After death, putrefying bacteria grow and multiply in the corpse, so that protein, fat and carbohydrate are decomposed into simple organic matter and inorganic matter, while protein, fat and carbohydrate are decomposed into simple organic matter, food and putrid gas, so that the soft tissue of the corpse gradually decomposes and disappears. The process by which the soft tissue of a corpse is decomposed and disappeared by substances and decaying gases. (2) Corruption process: Corruption process: corpse odor: 3-6h:3 corpse green: 24-24 corpse green: 24-48h:3 putrefaction bubble: 3-4d:5 corrupt giant: 5-7d: putrefying bacteria: aerobic bacteria, (3) putrefying bacteria after death. Macroscopic venation of anaerobic bacteria corruption (4) Influencing factors Temperature: 20 ~ 1) Temperature: 20 ~ 35℃ Humidity: Generally, corpse tissues contain more than 70% water; 2) Humidity: Generally, corpse tissues contain more than 70% water; 3) air: aerobic bacteria; Factors of the corpse itself: aging, emaciation and dehydration. Edema, 4) factors of the corpse itself: aging, emaciation, dehydration, slow anemia, rapid edema and obesity. The order of decay of corpse tissues and organs is related to the density of organs, 5) the order of decay of corpse tissues and organs is related to the density and water content of organs, and 5) the forensic significance can roughly estimate the time after death. 1) can roughly estimate the time after death. Knowing all kinds of corruption phenomena of corpses, 2) knowing all kinds of corruption phenomena of corpses can avoid suspected mechanical suffocation or poisoning death. Or poisoned. 3) The corpse is highly corrupt, which can make the corpse submerged in water float, which is conducive to exposing crimes. Expose a crime. Autopsy should be carried out as soon as possible. 4) The autopsy should be carried out as soon as possible. 2. Molding a corpse Molding a corpse (definition: the corpse is placed in a humid environment, (1) Definition: When the corpse is placed in a humid environment, under the temperature conditions suitable for the growth of fungi, under the temperature conditions for a long time, a layer of white mildew spots and mildew filaments grows on the bare part or the bare whole body surface of the corpse, which is called a moldy corpse. A layer of white mildew spots and mildew silk was born, which is called mildew corpse. (2) Forensic significance 1) Personal identification is possible. Personal identification is possible. Some lesions can be found. 2) Some lesions can be found. We can do toxicology analysis. 3) Toxicological analysis can be carried out. 3. Definition of Avicennia marina: The soft tissue of the corpse gradually softens and liquefies after corruption; (1) Definition: After the soft tissue of a corpse decays, it gradually softens and liquefies until it completely dissolves and disappears, and the hair and nails fall off until it completely dissolves and disappears, leaving only bones, which is called a corpse. Skeletonized remains are called bones. Animal damage to the corpse will accelerate ossification. Animal damage to the corpse will accelerate ossification. Generally, the soft tissue of a corpse buried in the soil will turn gray and muddy. Body, 2 ~ 3 years later, the soft tissue becomes gray and turbid. Skeleton (2) Forensic significance Skeleton can preserve the traces of injury for a long time. 1) Injuries can be preserved on bones for a long time. Some metal poisons are poisoned, and bones can be used as experimental materials. 2) some metal poisons are poisoned, and bones can be used as test materials. We can determine the age, sex and race of the deceased. 3) The age, sex and race of the deceased can be determined. (2) Postmortem phenomenon of preservation The corpse is interrupted by some internal and external factors, which prevents the soft tissue from disintegrating and liquefying, and the corpse is partially or completely preserved, which is called preserving the corpse (corpse). Embalmed corpse (embalmed corpse). 1, Mummy (1) Definition: A corpse does not rot due to rapid evaporation of water, which is defined as dryness; a corpse does not rot due to rapid evaporation of water, but is preserved in a dry state, which is called mummy or mummy. The withered state is preserved, called mummy or mummy. (2) Formation mechanism and conditions 1) Environmental conditions: dryness, ventilation and high temperature are the environmental conditions for mummy formation; dryness is the first condition. The first condition. Mummy 2) Physical condition: emaciation and dehydration; Newborns, young children and the elderly; Physical condition: emaciation and dehydration; Newborns, young children and the elderly; Arsenic poisoning. Arsenic poisoning. Signs of mummies: shriveled, fragile or flexible and hard; (3) Signs of mummies: shriveled, fragile or flexible, hard, with reduced volume and weight, 70% smaller and 70% lighter than before; (4) Forensic significance: 1) Some pathological changes can be preserved before, and some personal characteristics and injury forms can be preserved before. 2) You can keep some personal characteristics and injury patterns. Nectar wax) 2. Definition of corpse wax: The corpse is soaked in wet soil with insufficient air for a long time. (1) Definition: When the corpse is soaked in wet soil with insufficient air for a long time, the corruption progresses and stops slowly, and the adipose tissue of the corpse stops slowly due to saponification or hydrogenation, and the adipose tissue of the corpse becomes yellow-white waxy substance due to saponification or hydrogenation. It's called corpse wax. Formation mechanism: It is a complex biological and chemical process. (2) Formation mechanism: It is a complicated biochemical process. Appearance of corpse wax: waxy, greasy and easy to collapse; (3) Appearance of corpse wax: waxy, greasy and easy to collapse, but brittle and fragile. And fragile. Forensic significance: preserve the wounds before death. (4) Forensic significance: preserve the wound before death. 3. Definition of Peat Tanned Bodies: (1) Definition: Bodies soaked in acidic peat swamps rich in humic acids and tannins stop developing due to the action of acidic substances, while corpses in peat swamps stop developing due to the action of acidic substances, and their skin is tanned, muscle and other tissue proteins are gradually dissolved, skin tanning, muscle and other tissue proteins are gradually dissolved, and bones and teeth are decalcified. Weight reduction, softening and bending, decalcification, and make the body obviously smaller, weight reduction, softening and bending, this kind of preserved corpse is called peat tanned corpse (preserved corpse is called peat swamp tanned corpse). Bog). Forensic significance: It can preserve the damage before death. (2) Forensic significance: it can preserve the injury before death. Impregnation) 4. Definition of immersion: After the intrauterine death of a fetus more than weeks, (1) Definition: After the intrauterine death of a fetus more than 8 weeks, it cannot be completely dissolved and absorbed, but is immersed in sterile amniotic fluid to change its autosolubility, completely dissolved and absorbed, and immersed in sterile amniotic fluid to change its autosolubility. This is called impregnation. Degree of impregnation: Grade I, Grade II and Grade III. (2) Degree of maceration: first degree, second degree and third degree. Soak in the third quarter and destroy the body 1. Animals destroy corpses and flies destroy corpses most frequently, followed by ants, leeches and flies, followed by ants, leeches, mice and birds. Dogs, fish, wolves, birds, etc. Fly maggots: 6 young corpses in summer are adult corpses 3 1, and fly maggots: young corpses in summer last for 6-8 days, and adult corpses last for 3-4 weeks. After being eaten by fly maggots, only bones are left. The soft tissue was eaten up by maggots, leaving only bones. 2. Ants and beetles: the epidermis falls off, the tissue is defective, and the wound edge regresses; Ants and beetles: the epidermis falls off, the tissue is defective, and the wound edge regresses. Ants can eat up the soft tissue of the corpse on the ground within 4 ~ 8 weeks, leaving only the periosteum to eat up the soft tissue of the corpse on the ground. Rodents: Biting corpses mostly occurs in eyes, lips and nose tip, 3. Rodents: Biting corpses are mostly in the exposed parts of the body such as eyes, lips, nose tip and auricle. The wound is not big, the edge of the wound is extremely irregular, and his body is exposed. The wound is small, the edge of the wound is extremely irregular, and there are small serrated teeth marks, and the depth is generally only to the subcutaneous fascia. The depth of small tooth marks is generally only to the subcutaneous fascia. The wound tissue is broken and torn, and the wound surface and wound edge are irregular. 4. Dog: The wound tissue is broken and torn, the wound surface and the edge of the wound are irregular, and there is no bleeding reaction. Tooth marks will be left on the broken ends of bones. There are dog paw prints on the body surface. No bleeding reaction. Tooth marks will be left on the broken ends of bones. There are dog paw prints on the body surface. 5. Birds: The wound edges are different in depth, rough and uneven, and the tissues are twisted and torn. Birds: The wound edges are different in depth, rough and uneven, with distorted tissues and bird's paw prints on the body surface. Nonsense, there are bird paw prints on the body surface. Aquarium animals: the damage is mostly in the protruding part of the body surface, which can eat ears. 6. Aquarium animals: the damage is mostly in the protruding parts of the body surface, which can devour the tissues such as ears, lips, eyelids and face and destroy the five senses. Eyelid, face and other tissues, destroying the five senses. Other postmortem injuries: heart massage, corpse disposal, drifting injuries; Two. Other postmortem injuries: heart massage, corpse disposal, drifting injury, dismemberment, postmortem traffic injury, autopsy. Corpse, dismembered body, traffic injury after death, autopsy. Animal damage to corpses: Inference of the time of death in the third quarter 1. Inferring time of death from postmortem phenomena (1) Inferring time of death from corpse temperature (2) Law of corpse cooling (3) Formula and method of inferring time of death from corpse cooling (2) Inferring time of death from supernatural reaction (3) Inferring time of death from various postmortem phenomena. Inferring the time of death according to histological changes. Inferring the time of death according to histochemical changes. Infer the time of death from the chemical changes of the corpse. Judging the time of death according to the growth law of insects. When the temperature is above 30℃, maggots grow 0.24 ~ 0.3 cm per day, and when the temperature is above 30℃, they grow 0.24 ~ 0.3 cm. The body length can reach 1.2cm 1.2cm, 0.3cm when it matures later. It can reach 1.2cm when it matures in about 4 to 5 days. After about 1 week, the pupa breaks its shell and becomes a fly. The soil nearby turned into pupae. After about 1 week, the pupa broke its shell and became a fly. In spring and autumn, maggots grow about 0. 1cm every day and pupate after several weeks. In spring and autumn, maggots grow about 0. 1 cm every day, pupate in about 2 weeks and become flies in a few weeks. Turn into a fly in four weeks. Generally, the fresh pupa shells of 1 day are reddish brown, and those of 1 ~ 2 days are reddish brown. Compared with 10 day, the pupa shell of 15 ~ 20 day is dark brown, dark brown and soft. 10 and 65438+ are dark brown. Pupa shells can be broken into pieces after more than 30 days. Fragile. Pupa shells can be broken into pieces after more than 30 days. At present, there are two main methods to infer the time of death by using the growth law of flies: ① Calculate the age of maggots by measuring the length of maggots found on corpses. Length, calculate the age of maggots. ② The fly larvae found on the corpse were cultured into adults in the laboratory, and the time of death was inferred. Culturing adults in the laboratory to infer the time of death. According to the degree of digestion of gastrointestinal contents, it is generally believed that when the stomach is full of undigested food in its original state, it will die soon after eating; Died soon after eating; Most of the stomach contents moved to the duodenum, and most of the stomach contents moved to the duodenum, where they were digested to a certain extent and died about 2 hours after eating. Digestibility, about 2 ~ 3 hours after eating; Empty stomach or only a small amount of digestion, empty stomach or only a small amount of digestion, digestion or food residue in duodenum, about 4 hours after eating; When there are digests or food residues, it takes about 4-5 hours after eating; Both the stomach and duodenum are empty. After eating for 6 hours, the stomach and duodenum are considered empty, and death is considered at least 6 hours after eating. When more than death.