Thanatology is the doctrine of death, its causes, mechanism, and symptoms. The main types of death are schematically distinguished: cessation of respiration (respiratory death), blood circulation (cardiac death), cessation of the function of vital parts of the central nervous system (brain death). As a result of these processes, general oxygen starvation occurs (see Hypoxia) and the death of the organism. All types of death are interrelated, although one of them is usually the main one. Identification of the main type of death is of practical importance, for example, for resuscitation (see. Revitalizing the body ).