Thanatology is the doctrine of death. Forensic Medicine
Forensic medical thanatology is aimed at studying the dynamics and stages of dying. One of the most important parts of this science is tanatogenesis, which determines the true causes and mechanisms of death, and also allows the creation of a more perfect classification of the circumstances of a person's dying.
The concept of death
Death - stopping life. It comes as a result of the termination of the functioning of all organs and is an irreversible process. As a result of the lack of oxygen, the body cells die, and the blood ceases to be ventilated. If there is a cardiac arrest, the blood flow stops performing its functions, which leads to tissue damage.
General concepts of thanatology
Thanatology is a science that reveals the patterns of dying. She also studies changes in organ function and tissue damage as a result of this process.
Forensic medical thanatology acts as a part of the basic science, examines the process of death and its consequences for the whole organism in the interests and purposes of the investigation or for conducting an examination.
During the transition of a living organism to death, it undergoes different terminal states: pre-presonal( with oxygen deficiency), terminal pause( sudden stopping of respiratory system functions), agonal and clinical death. The latter comes as a result of cardiac arrest and cessation of breathing. The organism is between life and death, and with it all its metabolic processes are dying out.
Since dying is natural after the end of a person's life in old age, forensic medicine considers cases of premature death caused by the influence of various environmental factors. 
After clinical, biological death occurs, as a result of which irreversible changes occur in the cerebral cortex. In hospital conditions, it is easier to make a conclusion about the coming death than outside it, in the absence of special tools and instruments. Representatives of the authorities often use the term "moment of death", which forensic medicine regards as the exact time of its onset.
Signs of death
In order to establish the exact time of the end of life, it is necessary to know the signs of the onset of death, which is studied by thanatology. This is primarily oriented: immobility, lack of pulse and respiration, pallor, complete absence of reactions to various kinds of effects.
There are also reliable signs: the temperature drops to 20 °, Lärsche spots appear, early and late cadaveric changes develop( staining, stiffening, putrefaction, and others).
Resuscitation and transplantation
Resuscitative measures are taken in order to preserve human life, when the body functions lose their efficiency. At the same time, irreparable injuries and damage can be caused in the process due to inaccuracy or incompetence of doctors. Judicial tanatology is aimed at identifying the circumstances of death as a result of resuscitation, which makes it possible to assess the injuries and help further investigation. The expert's task is to determine the severity of the injuries inflicted and their role in the process of dying.
The essence of transplantation is the transplantation of organs and tissues from one to the other patient. The law provides that this activity can be carried out only if there is no chance of preserving life and normalizing the health of the donor. In case of craniocerebral trauma, if there is no hope of saving life, resuscitation can be carried out for the purpose of preserving the remaining organs that can be used for transplantation. Thus, the bone marrow can return to normal functioning within 4 hours, and the skin, bone and tendons up to a day( in most cases, 19-20 hours).
The basics of thanatology define the conditions and procedures for conducting transplantation and seizure of organs that are to be performed in public health care. Transplantation is carried out only with the consent of the two parties involved in the operation. It is prohibited to use the donor's biomaterial in case he was against it during his lifetime or his relatives revealed their disagreement.
The removal of organs is possible only with the permission of the head of the forensic department, and in the presence of the expert himself. The procedure should not in any way lead to disfigurement of the corpse.
Since thanatology is the doctrine of death, the organs and tissues withdrawn during the examination can be used as educational and pedagogical material. This requires the permission of a forensic expert who examined this corpse.
Categories of death
The death science considers only two categories of death:
- Violent. It occurs as a result of injuries and water injuries caused by some kind of environmental factors. It can be mechanical effects, chemical, physical and other.
- Non-violent. It happens under the influence of physiological processes, such as the onset of old age, fatal diseases or premature birth, as a result of which the fetus has no chance of survival.
Causes of violent and non-violent death
Forced death can occur for three reasons, as the science of thanatology says. It's murder, suicide or an accident. The forensic experts are engaged in determining what kind of a case belongs to each particular case. In doing so, they inspect the scene and collect evidence of the causes of death. These actions help to confirm that the end of life came by violent means.
The second category is a sudden and sudden death. In the first case, the end of life occurs as a result of illness. In particular, at which the diagnosis was made, but there were no valid reasons for the onset of death. In the second case, dying may come from a disease that occurs without any symptoms.
Types of death
Thanatology determines the types of death, depending on the factors leading to its onset. Thus, the violent end of life can be attributed to the impact of electric current and temperatures that are incompatible with survival, mechanical damage and asphyxiation. To the sudden death can lead to diseases of various organs with all sorts of complications, leading to a fatal outcome.
Due to the fact that a large number of medicines are used under current conditions and various types of operations are carried out, it is possible to find out thаnatogenesis at a deep analysis and examination of the corpse at the opening by a group of specialists.