/kloc-Claude Bernard, a famous French physiologist in the 9th century, said: Medicine is a science about diseases, and physiology is a science about life. Contemporary physiology and medicine have developed rapidly, and some ancient disciplines have undergone revolutionary changes. The newly formed and emerging interdisciplinary subjects put forward new ideas and requirements for the theory and practice of medical science. In order to popularize physiological and medical knowledge, meet the needs of teenagers for physiological and medical knowledge, and improve their physical and mental health, this book is specially written. This book has a new theme, in order to broaden the minds and horizons of teenagers: it covers a wide range of contemporary physiological and medical knowledge, such as the essence of life, bioelectricity, cardiopulmonary bypass, heart transplantation, hypothermia anesthesia, holographic medicine, human beings and the environment, and so on, in order to get some enlightenment for teenagers.
Health, a Chinese word, means that a person is in good physical, mental and social condition. Health is the basic right of people and the first wealth of life. The traditional concept of health is "disease-free health", while the modern concept of health is overall health. The World Health Organization puts forward that "health is not only the absence of physical diseases, but also mental health, good social adaptation and morality".