People can normally hold their breath for more than 30 seconds, why not strangle their necks for a few seconds?

The breathing action realizes the gas exchange between the human body and the outside world. Through breathing, on the one hand, oxygen in the air can enter our body and participate in the metabolism of the body; on the other hand, carbon dioxide produced by the metabolism of the body can be discharged. < / P > < p > since breathing is mainly controlled by the respiratory center, whether you want to or not, the body must complete the breathing action, which is irresistible to anyone. < / P > < p > however, it has been proved that in terms of breath control, you can only “win for a while, not for a lifetime”. The reason is that our body has a whole set of control system to control breathing, which is also the highest protection of life evolution. < / P > < p > respiratory center is a group of nerve cells that produce respiratory rhythm and regulate respiratory movement in the central nervous system. They are distributed in the cerebral cortex, diencephalon, pons, medulla oblongata and spinal cord, and participate in the generation and regulation of respiratory rhythm, so as to realize the normal respiratory movement of the body. < / P > < p > under normal conditions, the respiratory rate is 16-20 times / min, the rhythm is regular, the breathing movement is even, silent and effortless; the ratio of breathing and pulse is 1:4, that is, breathing once and pulse beating four times; abdominal breathing is the main method for men and children, and chest breathing is the main method for women. < / P > < p > however, in some cases, breathing can also change. This involves the two major respiratory regulation of the human body, respiratory reflex regulation and chemical regulation. Among them, reflex regulation includes lung stretch reflex, proprioceptive reflex and defensive reflex. < / P > < p > proprioceptive reflex: it is the afferent impulse of proprioceptor of respiratory muscle that participates in maintaining normal respiration. When the resistance of respiratory tract increases, it can strengthen the contractile force of respiratory muscle and increase the respiratory force. < / P > < p > defensive reflex: including cough reflex and sneeze reflex. When the receptors of laryngotracheal and bronchial mucosa are stimulated mechanically or chemically, they can cause cough reflex. When the nasal mucosa is stimulated, they can cause sneezing reflex to eliminate respiratory tract irritants and foreign bodies. < / P > < p > chemical regulation is a very important regulation of human body, especially when the internal and external environment of human body changes dramatically, it can play a very good protective role. This includes: the stimulation of CO2 to respiration, the decrease of PaO2 to stimulate peripheral chemoreceptors, and the effect of hydrogen ion on respiration. < / P > < p > the stimulation of CO2 on respiration: the decrease of PaCO2 in the blood can cause apnea; the increase of PaCO2 can stimulate the peripheral and central chemoreceptors, and the reflex can cause the deepening and acceleration of respiration. In severe cases, it can cause muscle rigidity, even convulsion, and cause CO2 anesthesia leading to apnea. If PaO2 is too low, it will inhibit breathing, weaken or even stop breathing. < / P > < p > with the above reflections, when people hold their breath, with the increase of CO2 and the decrease of PaO2 caused by holding their breath, they reflexively force the human body to breathe. Therefore, ordinary people can’t hold their breath for too long. Although some athletes can hold their breath for a few minutes, or even more than ten minutes. But ordinary people, I suggest you don’t try. They are trained professionally. Back to the topic, although people can’t hold their breath for a long time, it’s OK to hold it for a while. But why does strangulation quickly lead to unconsciousness? < / P > < p > at the moment of strangulation, whether the trachea is pinched or not is not important. Even if you can’t breathe at all, you still have dozens of seconds to wake up. The anesthesiologist will ask the patient to hold his breath for 30 seconds in the preoperative anesthesia evaluation of the operation patient. If he can reach the goal, he may think that his breathing problem is not serious. Otherwise, the anesthesiologist will further investigate the patient’s respiratory problems. The real cause of unconsciousness is the strangulation of the arteries on both sides of the neck! < / P > < p > although normal people have four blood vessels for the brain: bilateral internal carotid artery and vertebral artery. However, in human anatomy, the blood supply of internal carotid artery is 2 / 3 of the anterior telencephalon and the anterior part of diencephalon, while the blood supply of vertebrobasilar artery is 1 / 3 of the posterior telencephalon, the posterior part of diencephalon, brainstem and cerebellum. Anatomically, the area responsible for consciousness is in the anterior telencephalon. Therefore, the internal carotid artery blood flow suddenly interrupted, the fastest few seconds can lose consciousness! < / P > < p > now, you know what’s going on. For the sake of safety, we must not strangle and frolic in our life. In addition, once strangled by bad people, don’t try to pull the rope, but try your best to turn your head, even if one side of the artery is not strangled, you will have a certain resistance! 08/16/2020