What does death really mean?

The medical concept of brain death The death of an individual is a process. In humans, the heart or brain usually stops working, which is a sign that a person's life is irreversibly dying. However, the remaining organs and tissues of the body can continue to survive for a long time. For example, after cardiac arrest, respiratory epithelial cells can continue ciliary movement; Some cells can survive 120 hours. During this period, organs and tissues (such as kidneys, islets, etc. ) can survive after being transplanted into other individuals. This creates conditions for medical organ and tissue transplantation. At the same time, it also raises a question of how to judge people's death in medicine and law. Clinical death and biological death should first cause the cessation of breathing and blood circulation. Therefore, death can be divided into two stages: clinical death (or relative death) and subsequent biological death (or real death). In the stage of clinical death, although breathing and heart activity have stopped, tissues and cells have not stopped their life activities. Sometimes active first aid methods can be used to restore the basic life functions of the body, which is called "bringing back the dead". According to foreign literature, the clinical death time is generally within 5 ~ 7 minutes, but several patients who have died for tens of minutes have been successfully rescued in China. Biological death refers to the irreversible termination of life activities of tissues and cells, which generally occurs when a large number of individual cells die. Since the 1960s, organ transplantation has been widely used in clinic, and it is often necessary to remove relevant organs from the deceased for transplantation. Therefore, when the real death occurs has become a very important issue in clinical practice. In people's daily life, it is customary to take cardiac arrest as the sign of death. The progress of modern medical technology has broken this traditional concept. At present, it is not uncommon for patients with cardiac arrest to be saved, but patients with brain death are still helpless. Therefore, since the late 1960s, some people in the medical field have argued that cardiac arrest and respiratory arrest should not be regarded as signs of clinical death, but as the boundary between life and death. Its specific signs are general coma, disappearance of reflex, and plain EEG. The legal judgment of death shows that western society attaches great importance to the legal judgment of death. Because organ transplantation needs to ensure the survival of organs, at the same time, it must be confirmed that organs are obtained from dead patients. In addition, in civil or criminal cases, it is sometimes necessary to determine which comes first, which is of great significance to property inheritance, insurance or right of relatives. Therefore, it is necessary to legally determine the signs of judging death. The United States is the first country in the world to put forward "brain death" as a criterion. From 65438 to 0968, a special committee of Harvard Medical School described brain death in detail for the first time. 1980, the United States promulgated the unified death judgment act, which legally determined the standard for judging death. In addition to the United States, Britain, France, Finland, Italy, Australia and other countries have also enacted laws to recognize brain death as the basis for declaring death.