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National Geographic has calculated that the human body produces more than 60 liters of tears during a lifetime. What is their function and why do we cry? At some point, scientists asked this question, not believing that nature endowed a person with the ability to cry just like that, and seriously began to look for a scientific explanation for tears. It turned out that tears caused by emotions are different from those that come to the eyes from the wind, smoke or other irritant. The first arise as a result of processes occurring inside the body. The second are formed spontaneously. Their chemical composition is also different: tears from emotions contain more proteins and hormones.
What are tears
Each of us has tear glands that are constantly active and moisturize the surface of the eye throughout the day. Under the influence of emotions or stimuli, the lacrimal glands speed up their work, and we begin to cry. But what are tears?
A tear is a chemically specific liquid, the main task of which is to moisturize, cleanse and protect the cornea and conjunctiva of the eye from microbes. This substance consists mainly of water, sodium and potassium chlorides. In addition, it contains lysozyme, an enzyme due to which tears have a bactericidal effect (same as saliva and breast milk). By the way, the bactericidal properties of tears were discovered by microbiologist Alexander Fleming long before the discovery of penicillin. But not all the fluid produced by the lacrimal glands is the same. There are three types of tears: basal, reflex and emotional.
Basal
They are produced by the eye all the time. Every time we make a movement for centuries (and this can be about 6 thousand times a day), the surface of the eyeball is slightly moistened. Depending on the characteristics of the body, approximately 1 g of basal tears can form during the day. Their main function is to protect, nourish and moisturize.
The basal tear consists of 3 layers. The first is mucus, which keeps tears in the eye. The second layer is responsible for hydration and prevents the growth of bacteria. The outer layer is lipid. Its main task is to keep the surface of the eyeball smooth. If the gland does not produce enough basal fluid, a condition known as dry eye occurs.
Reflex
Reflex tears roll into the eyes in response to irritation (this can be wind with sand, smoke, or fumes from chopped onions). The mechanism of production of such tears is quite easy to explain. There is a sensory nerve in the cornea. It is he who sends signals to the brain when something gets into the eye. In response, the brain transmits impulses to the lacrimal gland and it begins to produce a protective fluid.
The peculiarity of reflex tears is that a fairly large number of them are produced at a time, which makes it possible to wash off everything superfluous from the surface. A reflex tear is about 95% water. But besides it, the composition of the substance also includes substances with a bactericidal effect. Their role is to protect the eye from dangerous microorganisms that could penetrate along with the irritant.
Emotional
They appear before our eyes due to certain emotions. The researchers studied the chemical makeup of emotion-induced tears and found that it was drastically different from the other two types. It turned out that when we cry with grief or joy, a liquid containing a relatively large amount of protein and hormones flows down our cheeks. Most often it is prolactin and corticotropin. If tears appear in the eyes due to a stressful situation, then they usually still contain adrenaline and norepinephrine. And if a person cries from severe pain, then his tears may contain opiates that have an analgesic effect.
Different theories about the origin of crying
People aren’t the only ones who can cry. Yes, it is quite possible to see crying elephants, otters, seals and crocodiles. However, animals do not cry out of pity or pain. For them, this is just a physiological way to get rid of excess salt. But why a person cries, researchers have several theories. In addition, different versions were put forward at different times.
In the XNUMXth-XNUMXth centuries, it was believed that in strong emotions the human heart heats up, and the body produces special steam to cool it down.
And now the tears are nothing more than a condensate of that same vapor that has accumulated between the brain and the eyes. And who knows how long people would have continued to believe in this if in 1662 the anatomist Nils Stensen had not made a discovery: the source of tears is the lacrimal gland.
Almost 300 years later, the scientist William Frey, having studied the chemical composition of emotional tears, suggested that their task is to remove accumulated proteins and substances from the body, formed due to stress. This theory looks quite plausible, but even it does not answer all questions. For example, why the number of tears does not depend on the severity of stress: while some people in a state of severe shock may not cry at all, others, even with mild stress, can sob for hours.
There is another version. Crying is a protective reaction of the nervous system in unsolvable stressful situations. By nature, it is laid down that a person, as a rule, reacts to stress either with an attack (defense) or an escape. But if neither the first nor the second is possible, we start crying. This is a kind of unconscious way to wait out the danger.
The fact that when a person is sad, he cries, no one is surprised. That’s the way we are. And for many, this explanation alone is enough. But not scientists. They studied the mechanism of tear formation. So, the American psychologist Jay Efran put forward his theory of the origin of crying. His version is also based on the fact that emotional tears arise due to stress. But the scientist is sure that in this case we cry not directly at the moment of tension, but at the next stage – when, after the extra efforts made by the body during the period of stress, inhibition of the nervous system occurs. And that’s when the crying starts. In this case, tears play the role of relaxation. Speaking scientifically, it is easiest to burst into tears at the moment of a sharp change in the activity of the sympathetic and parasympathetic nervous system, that is, during the transition from strong emotional stress to calm.
Today, researchers do not have a single version of why nature endowed a person with the ability to cry. According to another theory, tears are a way to show one’s weakness. Crying is a form of non-verbal communication. It is used by small children and paralyzed people.
Israeli researchers believe that tears are a social trigger for empathy. In many cultures, a crying person was perceived as someone in need of emergency care.
Tears of grief
Crying because of sad events (for example, the death of a loved one) is the first stage of accepting and understanding grief. According to researchers, it reduces sadness and anger by about 40%. However, tears do not always bring relief. A study in the Netherlands of about 200 women found that people who suffer from anxiety or depression feel worse after crying. However, psychologists say that the constant containment of emotions does not lead to anything good. From time to time, it is useful for each person to throw out everything that has accumulated along with tears. And this is not just a figurative statement. Together with the secretion of the lacrimal glands, the body is released from various substances. But we are talking mainly about crying, provoked by emotions. In this case, tears contain leucine-enkephalin. It is a peptide neurotransmitter that acts as a natural pain reliever. In addition, along with emotional tears, substances responsible for stress are removed from the body (some of them are toxic to our bodies). By the way, the signal of the nervous system that causes the secretion of emotional tears, among other things, activates the production of natural analgesics in the body. So sometimes crying can be pain-relieving.
Why do we cry with happiness
Although tears are usually associated with unpleasant emotions and grief, sometimes they also appear in moments of joy. American researchers decided to study why this happens.
The fact is that our body does not care because of what the overexcitation arose: from grief or great happiness. In any case, he tries to subdue strong emotions and restore balance. And he does it in the easiest way for himself – by crying. Tears block excess excitement. By the way, according to the same principle, another, at first glance, not quite adequate reaction of the body works – laughter during severe stress caused by grief. In this way, our body tries to relax and balance emotions.
Women’s and men’s tears
Why do some people have eyes, as they say, always “in a wet place”, while others do not cry even in extreme situations? The propensity to cry is influenced by various factors, including gender, the culture in which a person lives, his upbringing.
Women cry more often than men. This is a scientifically proven fact. German ophthalmologists have calculated that women can cry from 60 to 64 times a year, while men usually shed tears from 6 to 17 times over the same period. The researchers also determined that men cry on average for 2-4 minutes, while women’s tears can drag on for 6 minutes or longer. In addition, in 65% of cases, a woman’s cry turns into a sob, while a man can burst into tears only in 6 cases out of 100.
The main reason for these differences in the hormonal background. Women’s bodies contain prolactin, which, among other things, contributes to the production of tears. Testosterone, known for its ability to suppress tears, predominates in male bodies. By the way, after childbirth, the amount of prolactin in women’s bodies increases, and this fact explains why, after the birth of a baby, women become more whiny.
After the age of 40, the level of prolactin in women’s bodies decreases, which is why the frequency of crying in men and women evens out.
The fair sex is also more prone to tears during the premenstrual period (especially in the last third of the cycle), when hormonal fluctuations occur in the body (a sharp change in the amount of progesterone and estrogen). Also, a tearful mood is a common thing against the background of postpartum or postabortal depression. In these cases, the cause of female tears is also in the hormonal background. After childbirth or abortion, the production of progesterone in the body decreases sharply.
Separately, it should be said about children’s tears. According to scientists, babies cry for about 3 hours a day. They use tears as a way of non-verbal communication. So the baby can report that he is frightened of something, hungry, thirsty, or something hurts him. The crying of children before adolescence has no gender differences: the tearfulness of boys and girls is determined by the temperament of the child. But after puberty, everything changes.
But as for the social factor, it turned out that people living in countries where freedom of expression of emotions is welcomed cry more often. The social factor also partly explains why women cry more than men. In many cultures, it is unsuitable for the stronger sex to flaunt their experiences and pain, although, as recent studies show, keeping accumulated emotions in oneself is dangerous for health and life.
And one more interesting fact. It has been scientifically proven that crying women in the eyes of men lose their sexual attractiveness and cause mostly pity. It’s all about the specific smell of tears, which affects the brain of the stronger sex. Biochemical studies have shown that female tears can reduce testosterone levels in male bodies.
Cry as a sign of frustration
We all cry from time to time, but sometimes excessive tears can be a signal that something is wrong with your health. Sometimes crying for any reason indicates disorders of the nervous system. If this is the case, then you should contact a specialist who can determine the state of the nervous system and, if necessary, prescribe treatment.
In women, crying during PMS is a common occurrence, but if it turns into protracted tantrums, repeats often and for no apparent reason, then perhaps the cause is a serious hormonal failure. In this case, you will need to consult a gynecologist-endocrinologist. By the way, unmotivated mood swings, a tendency to tearfulness may also indicate problems with the thyroid gland.
If there are no deviations in terms of the endocrinologist and neuropathologist, it is possible that a psychotherapist should be consulted for help. People with apathy and low motivation are also often prone to tearfulness.
Crying as a form of manipulation
For many, the crying of other people is just a way of manipulation. However, researchers have their own assumptions about this. In particular, scientists believe that denial and rejection of other people’s tears usually occurs in people who are not capable of empathy. However, false tears as a way to achieve what you want also exist. However, not everyone knows how to cry “to order”. Most often, such abilities are found in sociopathic personalities. They do not know how to sympathize and do not need such an attitude towards themselves, but they are always ready to achieve their goal with the help of tears.
But the famous German psychiatrist Karl Leonhard believed that people of the hysterical (demonstrative) type are more likely to manipulate with the help of crying. As a rule, such people are very keenly experiencing all sorts of life dramas, especially of a personal nature, and often put their emotions on display. Their tears are the result of a specific organization of the psyche. In them, it resembles a nursery, so in most cases, such people use crying for self-defense. You can understand who is in front of you: a manipulator or a person looking for support, you can by his behavior. The tearful hysteria of the manipulators abruptly stops as soon as they get their way.
Why do we cry when we cut onions
Many people love onions but hate cutting them. After all, it is very difficult to chop this vegetable and not burst into tears. Tears shed over onions are reflexive. This is how the glands react to the evaporation of sulfonic acid contained in onion juice. This chemical irritates the mucous membrane of the eye and tears begin to flow involuntarily. Some varieties of garlic and the plant Petiveria alliacea, common in Guinea, also have similar tear properties. By the way, in 2015, Japanese researchers bred a special kind of onion – not causing tears. True, in the end it turned out that the taste of the new vegetable also differs from the usual onion.
To prevent tears from flowing while cutting onions, it is useful to use a proven folk method: moisten the knife in water, and cool the vegetable itself before chopping. Thanks to this manipulation, it is possible to slow down the spread of a gaseous substance from onion juice. And of course, it is better to take the sharpest knife for cutting – it damages fewer vegetable cells and, as a result, less tear substance is released.
benefits of crying
Crying can trigger many positive reactions in our bodies. During crying, different muscle groups relax, the heartbeat slows down, and blood pressure decreases. Crying eliminates emotional tension and even helps to supply the brain with oxygen.
By the way, in the capital of Japan there is a hotel whose rooms are specially designed for those who want to cry to their heart’s content.
Interestingly, according to the observations of psychologists, tears bring relief faster if you cry in the presence of a loved one who is able to support and console. But if a person feels guilty for his crying, then he will not only not bring relief, but will worsen the condition even more.
They bring relief, allow you to relieve emotional tension, calm your nerves, release negative emotions, or help express happiness. Tears are not a sign of weakness or over-sensitivity. This is a physiological reaction of our organisms. When it comes to the causes and consequences of crying, multiple studies provide conflicting results. It is impossible to say unequivocally that tears are good or bad. They are just there, as are all human emotions. Sometimes we lead them, sometimes they lead us. The main thing is to try to observe the measure in everything.