Why the tear is salty. How to explain to the child why tears are salty

Some children's questions can confound any adult. So, many can not immediately answer why the tear is salty. Understand the knowledge of the physiological processes taking place in the body.

Where do they come from and why do they need tears?

In the area of the eyeball, under the frontal bones of the skull, there is a special almond-shaped gland. It produces a tear fluid. From this gland to each eye and eyelids pass tear ducts. On them, and this fluid moves. But this does not explain why the tear is salty.

When a person blinks, the iron is excited and starts to work. Through the channels to the eyeball receives fluid that it washes. Tears of each person are sterile, they contain special substances - enzymes. They are able to destroy bacteria and thereby protect the eyes from potential infection. Enzymes not only protect the eyeball, but also help get rid of foreign bodies that have got into it. In addition, they moisturize it.

Causes of salinity

As a result of the research it was established that the biological fluid produced by the amygdala consists of 99% pure pure water (the formula of which is H ₂ O). The remaining 1% contains various additives, one of which is sodium chloride. In tears, its content is about 0.9%.

This is the reason why tears are salty. The answer is clear to most adults. But nevertheless, even they find it difficult to understand why the organism is arranged in this way.

Less than 1% of sodium chloride, which is contained in tears, gives them a pronounced salty taste. In some cases, the concentration of this substance can vary.

Interesting Facts

Many people, talking about why tears are salty, say that their taste can change. It depends on the concentration of sodium chloride in this biological fluid. This, in turn, is influenced by why a person cries.

For example, it is established that in tears of joy the low content of various trace elements and salts. The same can be said for tears that appear in front of young children. At the same time the thyroid gland is in a state of rest, and the adrenal glands, the cortex of the brain and the heart come into activity.

The most salty, according to endocrinologists, are tears of self-pity. In this case, the amplitude of the thyroid function increases markedly, and the cerebral cortex joins this process. Simultaneously, the adrenal glands begin to function intensely, the frequency of contractions of the cardiac muscle increases. These doctors can explain in a little more detail why the tear is salty.

The mechanism of crying

If a person is overly upset and begins to cry, many of his organs start working in a different mode. At a strong physical load the organism is in the same condition. True, in the latter case, sweat is allocated. By the way, he tastes like tastes. In addition to sodium chloride, magnesium, potassium, adrenaline and norepinephrine are in the pot. All this gives the biological fluid a bitter taste.

The tears released during crying are concentrated in most cases. Eyes with this blush, and the skin as if "burned out." Partly explain why the tear is salty, can be increased activity of the thyroid gland, adrenal gland, cerebral cortex and heart.

Biological features

In addition to tears in the body are other fluids. They all contain a certain amount of chloride and sodium ions. They are found in urine, saliva, sweat, secretion of sputum and even in the blood. This substance is necessary for the body in order to maintain the volume of fluid necessary for functioning and to adhere to osmotic constancy.

For example, substances such as sodium and potassium ensure the integrity of the cells, in addition, they also take an active part in the conduct of nerve impulses. Sodium ions are involved in the process of transporting sugars and amino acids directly into cells. In this case, there is a regularity: the higher the concentration of sodium ions in the intercellular fluid, the better will be the transport of amino acids into the cells.

Also, substances such as sodium and chlorine are necessary for the digestion process, they participate in metabolic processes and create the necessary balance of the acid-base level in the cells. Therefore, to underestimate the importance of sodium chloride in the body is not worth it.

Children's curiosity

Of course, telling a child about the functioning of organs and systems and the importance of the presence of sodium chloride in the body will be useful. But it's unlikely that the kid will understand him. Therefore, it is better from another position to approach the story about why tears are salty. To explain to the child it is possible so.

The usual water freezes in the frost, and the salty water remains in its liquid state long enough. If the organism was arranged differently, then the eyes would freeze in winter even with a slight cold. It would not even be necessary to say that it would be impossible to cry on the street. Do not forget that the eyeball is constantly washed by tears, even when a person does not cry. The concentration of salt in tears is such that they do not freeze even at -70 ° C.