Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine
With strangulation asphyxiation (hanging, looping), the neck organs are squeezed by a loop in which the ring, knot and free end are distinguished (the latter is fixed immovably).
On the skin of the neck from the impact of the loop, damage is formed – a strangulation furrow. Depending on the diameter or width of the loop, the pressure and the duration of compression, it can have a different width and depth. Rigid and semi-rigid loops during tightening around the neck cause damage to the epidermis, which are subjected to posthumous drying (parchment). Because of this, the strangulation furrow is clearly distinguished in the form of a dense, somewhat in-depth brown band, covering completely or partially the circumference of the neck.Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine. If the loop was soft and wide, and neck compression short, then the strangulation furrow may be slightly visible, and sometimes even absent.
A stranded groove that completely surrounds the entire circumference of the neck is called closed, and the interrupting or embracing only part of it is unclosed. Like loops, strangulation furrows are single and multiple.
In the forensic medical examination, the corpse is established and reflected in the research part of the expert’s conclusion such features of the strangulation furrow as its location, direction (horizontal or oblique), closedness, width, depth, color, density, relief (surface character), others features. From the width and the relief of the furrow, one can sometimes judge the material from which the loop was made.
When inspecting the corpse at the scene, the loop from the neck, as a rule, is not removed.
Hanging is a form of strangulation asphyxia arising from the compression of the neck’s organs by a loop drawn under the weight of the body of the deceased.
In social and legal terms, hanging is most often suicide, although there are also murders and accidents.
When hanging in an upright position, the legs usually do not touch the supports. When hanging in a vertical position with bent legs, sitting, reclining and lying down, the body touches the support, and to squeeze the organs of the neck of the loop, effort is sufficient from 4 to 10 kg.
Death in hanging is caused not so much by violation of airway patency, as by compression of the blood vessels of the neck. As a result, the blood supply to the brain is disrupted, there is a rapid loss of consciousness, because of which a person, as a rule, can not independently escape from the loop, and then the death of brain cells occurs.
The hinge node when hanging is most often located behind, in the nape of the neck (typical hinge overlap), less often on the side or front surface of the neck (atypical hinge overlap).
In the forensic medical examination of a corpse, in cases of hanging, there are signs of acute death and particular signs of hanging. The same applies to other types of mechanical asphyxia, so that in order not to repeat, here and below we will only consider specific features of a specific type of mechanical asphyxia.
Particular signs of death. 1. Location of the strangulation furrow when hanging in the upper part of the neck. The furrow has an oblique direction, usually unclosed and uneven in depth (deeper on the side of the neck opposite to the site of the node).
2. Fractures of the hyoid bone or thyroid cartilage of the larynx with hemorrhages in surrounding soft tissues (a sign of unstable).
3. Hemorrhages in the subcutaneous tissue and neck muscles. They are formed as a result of both compression and stretching of the neck. Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine.
4. The tongue often protrudes from the mouth and is impaired by teeth.
5. Transverse tears of the inner membrane (intima) of the common carotid arteries. Occur due to neck stretching.
6. Cadaver spots on the lower limbs, forearms, and hands (when the corpse is in the vertical position for a long time).
In doubtful cases, in order to exclude the hanging of a hanging (that is, killing in some way with the subsequent suspension of a corpse), histological examination of the strangulation furrow is performed to reveal signs of its lifetime.
Loop Removal is a kind of strangulation asphyxia that occurs when the neck is looped evenly and tightly. More often than not, this happens with murders, very rarely – in case of accidents and suicides. Neck compression is accomplished by tightening the knot with the loose ends of the loop or by twisting. By the mechanism of the onset of death, looping is in many respects similar to hanging.
Particular signs of death. 1. The location of the strangulation furrow is more common in the middle section of the neck. The furrow has a horizontal (that is, a transverse direction to the neck) direction, usually closed and uniform in depth along the entire circumference of the neck.
2. Possible fractures of the hyoid bone, cartilage of the larynx with hemorrhages in surrounding soft tissues.
3. Hemorrhages in the subcutaneous tissue and neck muscles. They are formed as a result of the compression of the tissues by a loop.
Depression by parts of a person’s body is a kind of strangulation asphyxiation, arising from the compression of the neck with fingers, between the shoulder and forearm, between the hip and shin, foot, etc.
Particular signs of death. 1. Scuffs and bruises on the neck. Most often appear on the anterolateral surfaces of the neck. Bruising is oval and small in size from the pressure of the pads of the fingers, abrasions – an arcuate shape from the action of the nails. When the neck is compressed between the forearm and the shoulder, there is usually no external damage to the neck.
2. Hemorrhages in the subcutaneous tissue and neck muscles. As a rule, they are more extensive than external damages.
3. Fractures of the hyoid bone, cartilage of the larynx with hemorrhages in the surrounding soft tissues. In this case, muff-shaped hemorrhages enveloping the vascular nerve bundles of the neck, trachea and esophagus are revealed. This characteristic is noted frequently.
If the victim resists, she is subjected to repeated attempts at handcuffing. The attacker puts pressure on her 46
chest, abdomen and limbs. Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine. As a result, additional randomly distributed lesions appear on the neck, multiple bruises, sometimes hemorrhages, liver ruptures, rib fractures.
Asphyxia from compression of the chest and abdomen – a kind of compression asphyxia due to the limitation of respiratory movements of the chest and a sharp violation of blood circulation from strong pressure on the chest and stomach. Pressures are usually made by any heavy objects, fallen or overturned on the victim and severely limiting or stopping the respiratory movements of the chest and abdomen. From a sharp increase in intra-thoracic pressure, blood flow from the peripheral parts of the body (head, limbs) to the heart, as well as arterial blood from the lungs, is disrupted.
Particular signs of death. 1. Severe cyanosis of the skin of the face, neck, upper and lower extremities with multiple small hemorrhages in the skin. A person with these signs is called an ecchymotic mask (ecchymosis – intradermal hemorrhage).
2. Disturbance of outflow of arterial blood from the lungs. At autopsy, carmine edema of the lungs is observed-the lungs are swollen, bright red in color. This feature is rare.
3. Impressions of a relief of clothes, seams or folds of linen on a skin of a breast, a stomach, a back.
4. Fractures of individual ribs. As a result of severe compression of the thorax and abdomen, multiple fractures, ruptures of internal organs and other gross injuries are formed. Death does not come from mechanical asphyxia, but from blunt trauma.
Closing the breathing holes is the form of obstructive asphyxia that occurs due to the closure of the mouth and nose holes with hands or soft objects. In infants, a so-called shedding is possible, i. E. accidental closing of the mouth and nose holes by any part of the body of the asleep mother during feeding or under other circumstances. There are no injuries, other than all-asphic attributes, here it is not found. True, in such a situation, another cause of death is possible: undiagnosed acute pneumonia in the life of the child, as a result of which respiratory insufficiency develops. In addition, death from the closure of the mouth and nose can occur in a patient with epilepsy, when during a fit he finds himself buried in a pillow. Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine. Epilepsy is used to diagnose medical records, as well as histological examination of the brain.
Particular signs of death. 1. Minor abrasions and bruises on the face around and near the mouth and nose holes. Sometimes abrasions have an arcuate shape from the action of the nails.
2. Abrasions and bruises on the mucous membranes of the lips (from pressing them to the teeth) and on the gums.
3. When closing the respiratory holes with soft objects in the cavities of the mouth, pharynx, in the respiratory tract, their particles (fluff, wool, textile fibers, etc.) are sometimes found. External injuries on the face in such cases may be absent.
Closure of the airway is a form of obstructive asphyxia, in which the foreign body, loose, semiliquid or liquid contents found in the airways are the cause of the violation or complete cessation of external respiration. To foreign bodies belong pieces of food, fragments of dental prosthesis, peas, coins, small children’s toys, etc., to loose and semi-liquid masses – sand, grain, vomit, to liquid – water, blood, kerosene, gasoline.
The features of the mechanism of the onset of death in these cases depend on the size and position of the foreign body. If it completely blocks the lumen of the airways, a variant appears that is typical of mechanical asphyxia.
A small foreign body, fixed directly at the glottis and not completely covering the airways, can cause swelling of the vocal cords, mucous membrane of the larynx and completely cover the airways. The same foreign body, fixed at the site of the bronchial discharge from the trachea, where there is a strong reflexogenic zone, can cause a primary reflex stop of the heart. Large foreign bodies are always found in a forensic study of a corpse. If the airways cover the loose bodies, then they are found in large numbers in the oral cavity, in the larynx of the larynx, in the trachea and in the large bronchi.
Semi-liquid food masses usually penetrate into the deep divisions of the respiratory tract. In such cases, the lungs are swollen, their surface is tuberous. The color of the lungs on the sections is variegated. When pressing on the lungs of small bronchi on the surface of the cut, particles of food masses protrude. When microscopic examination in the alveoli and small bronchi, muscle fibers, starch grains, plant cells and other elements of the food mass are found. Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine.
Closure of the respiratory tract by blood occurs, as a rule, in people lying on the back with fractures of the base of the skull, cut wounds of the larynx and trachea, abundant nasal bleeding. Aspirated (breathed) blood penetrates deep into the lung tissue, so the latter are enlarged in size (acute emphysema), on the cuts are dryish and mottled. Variation is determined by the alternation of small light and dark red polygonal areas. Microscopic examination confirms this picture, also revealing an accumulation of unchanged erythrocytes in the alveoli and bronchioles. The contents of the stomach and blood can end up in the respiratory tract posthumously, for example, during resuscitation (artificial respiration and indirect heart massage). However, in the absence of active respiratory movements, they fall only into the initial parts of the respiratory tract. The evidence of intravital penetration of blood and food masses is based on their detection in small bronchi and alveoli during histological examination.
Death in a confined space is a rare kind of mechanical asphyxia. It develops, for example, in children who, during games, hide in tightly locked chests, cabinets, refrigerators of the old type and can not get out of them, as well as people with a polyethylene bag thrown over their heads and snug against the neck. The same happens to a person who is in the compartment of a sinking ship or in some other confined space (for example, in an insulating gas mask). In such cases, in the air of a limited space, a high concentration of carbon dioxide released during breathing is gradually created, and death comes not so much from a lack of oxygen as from an excess of carbon dioxide. It has been calculated and experimentally proved that by the time of death of a person in a confined enclosed space, the ambient air contains a reduced but permissible concentration of oxygen, while the carbon dioxide content reaches a lethal level (8-10% or more). Carbon dioxide is always biologically active. Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine. Its concentration in the inspired air of 0.5% leads to increased respiration and increased ventilation of the lungs (concentration 2.5-3% is dangerous for the life of the child), 4-5% – to sharp irritation of the mucous membranes of the respiratory tract, higher – to the development of asphyxiation .
Forensic medical examination of the corpse in this case does not reveal any specific morphological changes, reveals only the signs of fast-pending death.
The fact of death from prolonged stay in a confined space can be established by calculation, based on the combination of the following initial data: the health status and age of the victim, the volume of the enclosed space and time spent in it, the amount of oxygen and carbon dioxide in the enclosed space by the end of the specified interval time. The conclusion about the cause of death is made in a hypothetical form, applied to the specific conditions of the place of death.
Drowning – This is the vast majority of accidents during bathing, water sports, accidental human entry into water (for example, in winter fishing).
There are also rare cases of suicide, sudden death as a result of the deceased disease or severe trauma in the water. There are drowning and as a way of killing when a healthy person is pushed into the water (say, from a bridge, from a boat) or brought to a helpless state by poisoning, intoxication, trauma, and then dumped into the water. Reservoirs are used in this case as a place of concealment of a corpse and its parts. Often there is a surfacing of corpses from former burials in the ground with the formation of new streams and reservoirs on the territory of old graves (cemeteries).
When drowning, the vital activity of the body is disrupted as a result of entering the fluid in the respiratory tract, most often water. Drowning must be regarded as a particular kind of oxygen starvation with a rather complex mechanism of the onset of death. It is a question of drowning in fresh water. Variants of drowning in other liquid media (sea water, liquid mud, gasoline, oily liquids, etc.) have not been studied enough.
There are two main types of drowning – true and asphyxic.
With true drowning the water penetrates deeply into the respiratory tract, into the lungs, and enters the blood in large quantities. Due to a sharp disruption in the physicochemical properties of the blood, a rapid cardiac arrest occurs. Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine.
Particular signs of death. 1. Persistent white or pink finely bubbly foam around the mouth and nose holes, in the airway lumen. Formed in the process of drowning with stirring the inhalation paths of water, mucus and air.
2. Acute emphysema of the lungs. Often on the surface of the lungs, shallow shallow parallel grooves are visible – the prints of the ribs. The swelling of the lungs results from the fact that water penetrating the respiratory tract presses on the air that remains there, the latter expands the lungs from the inside, pressing them against the walls of the chest.
3. Pale red hemorrhages on the surface of the lungs up to 0.5 cm in diameter with fuzzy boundaries (Rasskazov-Lukomsky patches). In their origin, these are the modified Tardieux spots, but more pale and vague because of the dilution of blood by water.
4. The blood in the left half of the heart is lighter than in the right side (due to the impurity of water).
5. The presence in the internal organs (excluding the lungs) and in the bone marrow of long tubular bones of plankton elements – the smallest microorganisms living in the water column and carried by the current. When drowning, plankton, along with water, penetrates into the bloodstream and flows through various organs through the flow of blood. Of practical importance is the so-called diatom plankton – a special class of algae that have a strong silica shell (shell), which does not break down when the corpse rotates, by the action of concentrated acids and alkalis. Establishing the presence of plankton is laborious enough and is conducted in forensic laboratories. It is usually resorted to in cases when other signs of drowning are doubtful or absent (for example, with pronounced decay of the corpse). To study from the corpse take an unopened kidney or a long tubular (femur) bone. It is necessary to investigate also a control sample of water from a reservoir in which a corpse is found. The coincidence of diatom species in the body of water and bodies proves not only the fact of drowning, but also that drowning occurred in a particular pond.
With asphyxial drowning water ingress into the upper respiratory tract causes a persistent spasm of the glottis with complete overlap of the airway lumen. Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine. Water into the lower respiratory tract and into the lungs does not enter or falls in a small amount in the final stage of dying.
Particular signs of death. I. At autopsy, there are signs of acute death, among which there is a marked swelling of the lungs.
2. A small amount of white or pink finely bubbly foam is possible around the mouth and nose holes.
3. The stomach and intestines often contain a lot of liquid. The diagnostic value of this sign is significantly increased if it reveals inclusions that are characteristic of the drowning environment (silt, algae, grains of sand, oil products, etc.).
One of the signs of drowning (a sign of VA Sveshnikov) is the presence of fluid in the sinus (cavity) of the underlying bone, which forms the base of the skull. It occurs in approximately 75% of cases with both types of drowning. However, there is an opinion about the possibility of postmortem penetration of water into this sinus.
Stranding furrow, Certain types of mechanical asphyxia – Forensic medicine