Let's learn to copy the party! The point is that you can't explain this problem clearly in a few words. Electricity and its uses have long been known and used by people. When hands are cold in winter, electricity and heat will be generated as long as you rub your hands hard with each other; If you wipe the metal bar with a piece of fur, more charge will be generated on the metal bar. At this time, when it touches a small piece of paper, the small piece of paper can be attracted and attached to the metal bar. As for modern families, almost everything is inseparable from electricity. Electric lights, electric fans, refrigerators, telephones, televisions and so on. But do you know that our human body also has electricity generation and constant change? As we said before, our human body is made up of many cells. Cells are the most basic unit of our body, because only when all cells in the body perform their duties can the life phenomenon of the human body continue. Similarly, from an electrical point of view, cells are also a basic unit of bioelectricity and a "micro-generator". It turns out that a living cell, whether in an excited state or a quiet state, is constantly changing its charge, which scientists call "bioelectricity". The potential a cell has when it is not stimulated is called "resting potential". The potential produced when cells are stimulated is called "action potential". The formation of electric potential is due to the positive charge on the outside of cell membrane and the negative charge on the inside of cell membrane. The state of charge inside and outside the cell membrane is called "polarization state" by doctors. Because of life activities, all cells in the human body will be stimulated by the internal and external environment, and will also respond to the stimulation, which is more obvious in nerve cells (also called neurons) and muscle cells. This reaction of cells is called "excitability" by scientists. Once the cell is stimulated and excited, the cell membrane will produce rapid and short-term potential fluctuation on the basis of the original resting potential, which can spread to the surrounding area, thus forming an "action potential". Since the above potential changes exist in cells, doctors can measure them with extremely sophisticated instruments. In addition, because the electrical changes under pathological conditions are different from those under normal conditions, doctors can see whether there is some disease in the organ composed of cells. There is an instrument called ECG recorder, which is used to check whether there is any disease in people's heart. This instrument can record the waveform image produced by the change of myocardial potential from a specific part of the human body, which is commonly called electrocardiogram. Doctors can judge whether the patient's heartbeat is regular, whether there is cardiac hypertrophy, whether there is myocardial infarction and other diseases by analyzing ECG. Similarly, the human brain can generate electric current like the heart, so doctors can record the EEG by placing an electrode recorder on the scalp of the patient, so as to know whether there is something wrong with the patient's brain. Of course, because the EEG is weak compared with the ECG, scientists have to enlarge the EEG by 654.38+00000 times to reflect the changes of brain tissue, such as whether there is a tumor in the brain and whether the subject may have epilepsy (commonly known as epilepsy). Scientists believe that with the development of electrophysiological science and electronics, EEG records will be more detailed, and even one day such instruments can correctly measure people's thinking activities. Electricity is ubiquitous in living things. Biologists believe that every cell that makes up an organism is a miniature generator. There are opposite charges inside and outside the cell membrane, positive charges outside the membrane and negative charges inside the membrane. The uneven distribution of potassium and sodium ions inside and outside the membrane is the basis of cell bioelectricity. However, the voltage and current of bioelectricity are very low and can only be measured with precision instruments. So bioelectricity was first discovered by Italian biologist galvanic until 1786. Any subtle activity of human body is related to bioelectricity. External stimulation, heart beating, muscle contraction, eye opening and closing, brain thinking, etc. Are accompanied by the generation and change of bioelectricity. When a certain part of the human body is stimulated, the sensory organs will be excited. Excitement travels along the afferent nerve to the brain, and the brain responds according to the information from excitement and gives instructions. Then the efferent nerve transmits the instructions of the brain to the relevant effector organ, and it will complete the corresponding action according to the instructions. The information conveyed by this process-excitement-is bioelectricity. In other words, the "stimulus response" between the senses and the brain is mainly realized through the conduction of bioelectricity. 1 ~ 2mV is generated when the heart is beating, 5 ~ 6mV when the eyes are opened and closed, and 0.2 ~ 1mV when the brain is reading or thinking. The bioelectrical changes of heart, muscle, retina and brain of normal people are very regular. Therefore, the patient's electrocardiogram, electromyography, electroretinogram, EEG and so on. You can compare it with healthy people and find symptoms. Among other animals, there are many creatures whose current and voltage are quite large. On the coast of some oceans in the world, there is a large seabird-warship bird, which has superb flying skills. You can catch the flying fish before it falls into the water and never miss it. After 10 years of research, American scientists found that the "electrical cells" of warship birds are very developed, and their retinas and brain cells constitute a set of functional "biological circuits". Their retina is a "biological radar" that is hundreds of times more advanced than any existing radar, and their brain cells are unparalleled "biological computers", so they have the above stunts. There are also some fish that have special power generating organs. For example, torpedoes widely distributed in tropical and subtropical coastal waters can generate a voltage of 100 volts, which is enough to kill some small fish. Electricity on the Nile in Africa contracted, with a voltage of 400-500 volts. The horizontal lines of Amazon River and Orinoco River in South America are shaped like trowels and yellow spoons. It is two meters long and can generate an instantaneous current of 2 amps and a voltage of 800 volts, which is enough to kill cattle and horses and even people in the water. No wonder some people say it is the "devil" in the river. Plants also have electricity in their bodies. Why do mimosa "bend down" and people feel shy when they touch it with their fingers? Why does the golden face of sunflower always smile at the sun? Why does the flytrap catch insects on leaves like a clever frog? It's all because of bioelectricity. For example, when the leaves of mimosa are stimulated, an electric current is generated immediately, and the electric current travels along the petiole to the small spherical organ at the base of the leaves at a speed of 14 mm per second, causing the activity of the spherical organ, which in turn drives the leaves to move and close. Soon, the current disappeared and the blade returned to its original state. In North America, there is an electric bamboo that people and animals are afraid to get close to. Once they accidentally touch it, they will be numb and even knocked down. In addition, some living things, including bacteria, plants and animals, can convert chemical energy into electrical energy and emit light without heating. Especially marine life, according to statistics, 70% species and individuals of shrimp and 70% species and 95% individuals of fish living in moderate depth can emit light. At night, in some areas of the ocean, biological light shines and connects together, forming an extremely spectacular marine spectacle. The bioelectricity phenomenon refers to the electrical phenomenon shown by organisms in their physiological activities, which is universal. There is a potential difference inside and outside the cell membrane. When some cells (such as nerve cells and muscle cells) are excited, action potentials can be generated and spread along the cell membrane. The potential changes of other cells (such as glandular cells, macrophages and ciliated cells) also play an important role in the completion of various functions of cells. With the development of science and technology, the research of bioelectricity has made great progress. Theoretically, a series of breakthroughs have been made in the characteristics of single cell electrical activity, nerve conduction function, bioelectricity generation principle, especially the establishment of membrane ion flow theory. In medical application, the comprehensive determination of organ bioelectricity is used to judge the function of organs and provide scientific basis for the diagnosis and treatment of some diseases. In our clinical work, we often encounter the concepts of excitability, excitability and excitability conduction, which are all related to blocking the bioelectricity next door. Understanding the basic theory of modern bioelectricity is of great significance for correctly understanding these concepts and the basic principles of ECG, EEG and EMG. There are several kinds of cell bioelectricity phenomena: 1. Resting potential The potential difference between the two sides of the membrane in a quiet state of tissue cells is called resting potential or membrane potential. When the cell is at rest, the positive charge is located outside the membrane (the potential outside the membrane is positive) and the negative charge is located inside the membrane (the potential inside the membrane is negative). This state is called polarization. If the potential difference between inside and outside the membrane increases, that is, the resting potential changes in the direction of increasing the negative value in the membrane, it is called hyperpolarization. Conversely, if the potential difference between inside and outside the membrane decreases, that is, the potential inside the membrane becomes negative, it is called depolarization or polarization. In general, if the extracellular potential is zero, the resting potential of nerve fibers is -70 ~-90 mV. The resting potential is caused by K+ leaving the membrane, which is negatively charged and positively charged. 2. Action potential When cells are stimulated, potential changes can occur on the basis of resting potential, which is called action potential. According to different recording methods, the waveform of action potential can be different. Microelectrodes were placed in the cells to record the rapid and reversible changes and show the spike potential. The spike potential replaces the exciting process of eye cells, which is a sign of the generation and conduction of excitement. The spike potential is shown as a gray sharp waveform on the oscilloscope, which can be divided into rising branch and falling branch. The rising branch is a process in which the negative potential in the membrane rapidly drops to zero, which is called membrane depolarization (depolarization), and then the potential in the membrane continues to rise beyond the potential outside the membrane, and the state in which the potential outside the membrane becomes negative and the potential inside the membrane becomes positive is called reverse polarization. Descending is a process in which the potential in the membrane returns to the original resting potential level, which is called repolarization. After the peak potential, there is a slight continuous and slow electrical change, which is called back potential, before it completely returns to the resting potential level. The bioelectric phenomena of myocardial cells are the same as those of nerve fibers and skeletal muscles, including resting potential and action potential when excited, but they have their own characteristics. When myocardial cells are quiet, the membrane potential is about -90mv. The principle of resting potential formation of myocardial cells is basically the same as that of nerve fibers. It is mainly caused by the diffusion of high-yield k+ in cells to the outside of the membrane at rest. Action potential is generated when myocardial cells are stimulated from resting state to excited state. Its waveform is very different from that of nerve fibers, and its main feature is that the repolarization process is complex and lasts for a long time. After a certain point of myocardial cells is stimulated to depolarize, it immediately spreads around until the whole myocardium is completely depolarized. The positive charge outside the depolarized cell membrane disappears, while the unpolarized cell membrane is still positively charged, forming a potential difference. The potential difference between the depolarized and unpolarized parts causes local current to flow from the positive electrode to the negative electrode. During repolarization, repolarization begins at the first depolarization point, and the film is positively charged, and the potential difference between repolarization point and unpolarization point is formed again, resulting in current. It can be seen that many electric pairs move at the same time until the whole myocardial cell is depolarized at the same time, regardless of their strength and direction. This electric couple, which represents the total effect of myocardial depolarization, is called equivalent electric couple. The structure of the heart is three-dimensional, and the direction of the couple changes all the time during depolarization, which is the main reason that affects the upward or downward wave on ECG. Because the size and thickness of each part of the myocardium are different, the depolarization of the heart follows a certain order, so the strength of the equivalent electric pair in the depolarization of the heart has been changing. It mainly affects the amplitude of each wave on ECG. The human body is a volume conductor and the heart lives in the human body. The equivalent couple produced by the heart has its potential distribution in all parts of the human body. During the cardiac cycle, the power intensity and direction of the cardiac equivalent couple are constantly changing. The potential in the body will also change constantly. From any two points of the body, use an instrument (electrocardiograph) to draw a curve, which is an electrocardiogram. With the development of molecular biology and membrane ultrastructure research, people try to understand the change of membrane permeability and the generation of bioelectricity from the molecular configuration changes of some special protein and other substances in membrane structure, which pushes the research of bioelectricity to a new stage. [Edit this paragraph] The mystery of bioelectricity has not yet been revealed, so the application should be cautious. Recently, biologists "eavesdropped" the "sound" of electrical activity in some parts of the human body and found that bioelectricity in the form of electric field plays a vital role in many physiological processes, such as embryonic development, cell division, nerve regeneration and wound repair. However, the exploration of it is not smooth. It was first reported in 1920 that electric field may affect cell behavior. At that time, Sven Ingfa, a Danish scientist, found that the external electric field caused the chicken neurons to grow in a special direction. In 2002, Colin mccaig of the University of Aberdeen in the United Kingdom discovered that bioelectricity played an extraordinary role in the process of corneal repair in rats. In normal cornea, corneal epithelial cells pump out positively charged sodium ions and potassium ions, and then pump out negatively charged chloride ions, thus generating a voltage of about 40 millivolts. The cells that repair the wound in the active stage of division can obtain important spatial information through the electric field and push the repair cells to the wound. If this electric field is cancelled, cells will divide in any direction; If the intensity of this electric field is artificially enhanced, cells far away from the wound will also start to divide along the plane of the electric field. Similarly, neurons use the electric field of cornea to reconstruct themselves. They found that the electric field of cornea can promote the growth of neurons at the wound. However, how does the electric field affect the behavior of cells? At present, scientists have not yet solved the mystery. Colin mccaig thinks there are two possibilities: one possibility is that the electric field attracts the charged protein or fat on the cell surface; Another possibility is that the change of voltage leads to the opening of the calcium channel on the cell membrane, which leads to the entry of calcium ions into the cell, thus activating the second signal molecule and making the signal transmit along the signal chain, but this has not been verified. At present, some institutions have introduced products that use bioelectricity for medical care. After studying for a few days, a training course claimed that it could cure all kinds of diseases, issued a technician certificate and collected more than 1000 yuan, but it was not approved by the national labor department. In the absence of medical school license and teaching space, it is worthy of our vigilance to call bioelectricity medical college. In particular, it is against the common sense of pathology to promote bioelectricity to treat all diseases. These alternative treatment techniques cannot be found in regular hospitals, so patients should be particularly cautious.