Everyone is equal when facing death, but the dying person will show a different expression. This is the last state when they bid farewell to the living world. is full of tragedy, depression and sadness.
Whether in movies and TV dramas or in the real world, we can indeed see some dying people in shed "cold" tears at the moment when they just closed their eyes. As the saying goes, the flowing person has no intention, and the viewer has his heart. So, where do these tears come from and why do they appear?
Some people explain that is the reluctance of the dying person to his relatives and friends, and a witness of tragedy, while others solemnly say that this is The dying person suffered great physical pain before his death and had nowhere to complain, and finally vented it through tears.
As the saying goes, the reason for the public and the reason for the mother-in-law, these explanations seem to be very reasonable, but if they ask them to explain the scientific basis in detail, there is no trace to be found.
In the folk and even in the religious field, there is a saying full of romanticism , saying that people will go through a process of leaving the body before and after death, , and this process will be extremely long and painful. Tears are born because of this process, so people in many places have tacitly understood and formed an unwritten agreement that filial sons and grandchildren cannot directly contact the body of the deceased, with the purpose of reducing the pain of the deceased.
Of course, this statement has no scientific basis, it only has a habitual and special thinking activity of human beings.
We all know that people have the supreme thinking ability in this world, but to put it bluntly, they are still a group of animals with greater sensibility than reason. always makes assumptions of self-comfort in some extremely special occasions, and these assumptions are just psychological hints of self-deception.
In fact, tears flow out of people's eyes when they are dying is just a normal physiological phenomenon.
First of all, you need to understand the principle of tears formation.
Human tears are divided into two properties, One is stimulating tears and the other is emotional tears.
irritating tears are that when the eyes exposed outside are stimulated by unknown reasons or are in a very dangerous situation, they will make conditioned reflex , which can protect the eyes. For example, when we cut onions or dust and gravel enter the eyes, these irritating substances cause our eyes to feel very uncomfortable.
At this time, the corneal nerves in the eyes will send signals to the central nerve of the brain to invade external stimuli. central nerve will issue instructions to the lacrimal glands, producing tears to dilute or clear external stimuli. Once tears are overflowing, they will flow out from the corners of the eyes. This is what we call tears.
Another type is emotional tears. Compared with the stimulating tears mentioned above, the latter is more like a subjective behavior with purpose and personal consciousness. When people face a very abnormal emotion, such as extreme depression, pain or abnormal happiness, etc., central nervous system will release brain pressure by activating the lacrimal glands.
No matter what kind of tear it is, it ultimately needs to be produced through the organ of the lacrimal gland. According to normal definition, tear refers to the behavior of excessive accumulation of tears secreted by the lacrimal glands, which can no longer be discharged normally and flow out of the palcipar fissure.
From a scientific point of view, the human body's sympathetic nerve controls the normal secretion of tear glands, while the parasympathetic nerve controls the secretion of large amounts of tear fluid. When is on the verge of death, the parasympathetic nerve is relatively excited, and will produce a large amount of tears. When the eyes are closed, it is squeezed and flows out from the corners of the eyes. If there are enough tears, tears can flow out even if the eyes are open.
Of course, there is another explanation for crying after death, that is, within five minutes after death, the pupils will gradually dilate and begin to lose their luster, and the eyeballs in them will also change from the original sphere to a flat structure.
At this time, because many organs in the human body are already in a stagnant state, the body cannot guarantee sufficient blood pressure, the air pressure inside the eyes of will quickly decrease, forming a relatively obvious air pressure difference with the external air pressure. Although the air pressure difference such as will not have a subversive effect, it is still more than enough to make the deceased shed the last tear.
In addition to crying, there are many phenomena that seem very bizarre when people are on the verge of death, but they can be explained by science. For example, the phenomenon of back to light that we often talk about is actually a short process in which adrenaline secretes all the last little energy. Once adrenaline is completely exhausted, people will turn from short excitement to the end of their lives.
In addition, Some people say that they will see the so-called white light when they are on the verge of death. is to find out. Dutch has a research team selected 344 patients for a special study in 2001. Most of the research subjects were elderly patients who survived while cardiac arrest . Among them, 18% of the patients have experienced near-death experience . Most people claim that they have seen white light when they are verge of death.
Later, scientists found through sampling research that the concentration of carbon dioxide in these patients with near-death experience is significantly higher than that of ordinary people. The white light seen by is likely due to hallucinations. Of course, this does not mean that it is caused by excessive carbon dioxide concentration, because the carbon dioxide concentration in some patients is normal, and the real reason is still being studied.
While we are studying the universe, when we look back, we can actually find that has not even studied and understood humans in this world, and many things in have not yet been explained scientifically, but we believe that there should be a scientific explanation for these things.
