Substances that make up our body. What does a person consist of? Chemical and mineral composition of the body. Elemental composition of organisms

Lesson Objectives

1. Expanding and deepening students’ knowledge about the role of metals in the life of the human body.
2. Development of independent work skills; the ability to use knowledge previously acquired in the study of biology and chemistry; work with tables; compare, analyze, draw conclusions.
3. Fostering a caring attitude towards nature and human health, a sense of teamwork, respect for each other, and responsibility for a common cause.

Equipment and materials

1. Demonstration material: table “Chemical composition of the human body”; cards with pictures for drawing up a diagram “Penetration of lead ions into the human body.”
2. Handouts: tables “Chemical composition of the human body”, “The influence of metals on the vital functions of the human body”, “Crossroads”; text summary of homework.
3. For practical work: solutions of lead and protein salts, test tubes, pipettes, stands.
4. Video film “Transport in the city.”
5. Excerpts from literary works about the influence of metals on the human body.
6. On the board there is an epigraph: “Nature does not accept jokes; she is always truthful, always serious, always strict; she is always right, but mistakes and delusions come from people” (W. Goethe).

PROGRESS OF THE LESSON

I. Organizational moment

Chemistry teacher. In the last lesson, we finished studying the topic “Metals”, during which we looked at metals as elements of inanimate nature. You know that the role of metals in inanimate nature is very great: they include 92 of the 114 chemical elements included in the periodic table. Today, with the help of a biology teacher, we will talk about the role of metals in living nature.

Biology teacher. Living nature includes all living organisms, including humans, so we will get acquainted with the role of metals in living nature using the example of the human body. ( The teacher asks the students to formulate the topic of the lesson, writes it on the board, and the students write it in their notebooks.)
Today we will remember what you learned about metals in chemistry lessons and about the human body in biology lessons in the 8th grade, generalize and expand this knowledge and apply it to clarify the role of metals in the human body. You will work in teams, so each of you has the opportunity to receive two marks - for individual work and work in a group. For correct answers to questions in chemistry and biology, you will receive two types of tokens. Three tokens of the same type will allow you to receive an “excellent” rating, two tokens will give you a “good” rating. In addition, each correct answer will earn your team 1 point (wrong answers do not count), all points are entered into the team table. Group work will be graded after homework has been reviewed and the lesson has been finalized. Grades for individual work - today at the end of the lesson.

II. Updating knowledge

Chemistry teacher. Nature has created many living organisms - simple and complex, similar and completely different from each other. Together with inanimate nature they formed a complex but harmonious system - the nature of the Earth. As an epigraph to our lesson, we chose the words of the great German poet Goethe. ( The teacher draws the students’ attention to the epigraph written on the board and reads the first part of it..) However, man, through his activities, violates the harmony of nature, thereby harming not only the environment, but also his own health. ( The teacher reads the second part of the epigraph.) A century and a half later, the poet’s words received, unfortunately, complete confirmation.

III. Main part

Biology teacher. The cells of living organisms, including humans, contain organic and inorganic substances. They are listed in the “Chemical composition of the human body” tables, which everyone has on their desk. Chemical elements and their compounds, necessary for the normal functioning of the body in relatively large quantities, are called macronutrients, and elements required by organisms in extremely small quantities are microelements. Among the macroelements there are both non-metals - oxygen, carbon, hydrogen, nitrogen, phosphorus and chlorine, and metals. Name them using the data in the table. 1. Among microelements there are also non-metals and metals. Using the table, try to name them. The data in the table shows how diverse the metals that make up the human body are.

Chemistry teacher. In what form are metals found in the cells of the human body? Let's remember what the biological role of the metals we studied in chemistry lessons is. To do this, we will use the summary tables in the chemistry notebook. ( Students repeat the biological roles of sodium, potassium, calcium, magnesium, and iron. Correct answers receive tokens.)

Biology teacher. Now look at the table. 2. How would you title it? ( Students become familiar with the contents of the table, suggest its name, write it above the table, and paste the table into their workbooks.) What conclusion can be drawn from the contents of this table? It is obvious that metals are necessary for the cells of the human body for normal functioning. Both excess and deficiency of metals have negative effects on the body, and some metals can even have toxic effects. ( The conclusion is written down in a notebook.)

Chemistry teacher. We tried to find confirmation of this in various literary sources. Using your tables, try to determine the effect of which metals we are talking about.

Table 1. Chemical composition of the human body

1. Quote from the article “Help Came Through the Internet” from Reader’s Digest magazine, October 1996:

“A young student studying chemistry at Peking University suddenly began to experience dizziness, severe intestinal cramps, and burning pain in her hands and feet. Then her hair began to fall out. Her parents rushed her to the hospital, but the girl fell into a coma.
According to doctors, dizziness and cutting pains in the palms and feet, as well as in the joints, indicated a serious neuralgic disorder. However, spinal puncture did not reveal any abnormalities. Tests for arsenic and lead poisoning also came back negative.”

2. Quote from Valentin Rasputin’s story “Live a century, love a century”:

(Students work with the tables and come to the conclusion that the first quote refers to thallium poisoning, and the second quote refers to zinc.)

Biology teacher. I would especially like to dwell on harmful effects heavy metals on the human body. One of the “suppliers” of heavy metals such as lead, copper, chromium is road transport, or more precisely its exhaust gases. Let's watch a short video clip ( a fragment of the video film “Transport in the City” is shown). This picture is typical for all large cities, including Chelyabinsk. Let's take a closer look at the effect of lead ions on the human body. In table 2 it is written that lead, even in small quantities, causes anemia, kidney failure, and brain diseases. In addition, lead can replace calcium in bones. How can lead ions enter the human body? Let’s draw up a diagram “Penetration of lead ions into the human body.” One student will do this work at the board, using magnetic cards with drawings, the rest will draw up a diagram in a notebook and accompany it with appropriate notes.

Table 2

Chemistry teacher. It has been established that the content of lead ions is especially high in areas adjacent to roads. This was tested by students from our school. There is a table on your tables. "Crossroads". It presents the results of studies of soil samples taken at the intersection of Dovator and Fedorov streets. As can be seen from the table data, the largest number of lead ions is found near the road itself, the smallest - at a distance of about 100 m. Let's check experimentally how lead ions affect living organisms. To do this, we will do a laboratory experiment “Interaction of lead salts with protein.” We will write the conclusion in a notebook. ( Students perform a laboratory experiment, independently draw a conclusion, and write it down in a notebook..)

Table 3. "Crossroads"

V. Homework

Biology teacher. Today we looked at the influence of some metals on the vital functions of the human body, but we did not pay enough attention to the problem of the penetration of metal ions into it. You will look at this problem while doing your homework. ( Groups of students are given homework of varying degrees of difficulty; lists of students in each group are distributed along with the text of the homework).

1st group. Consider the ways of penetration of sodium, potassium, calcium and iron ions into the human body, using the text of a chemistry textbook. Present the results in table form in your chemistry notebook.

2nd group. Familiarize yourself with the contents of labels and instructions on household chemicals and present your assumptions in table form.

3rd group. Using reference and additional literature, draw up diagrams of the penetration of selenium ions and heavy metals - copper, cadmium, mercury - into the human body.

V. Independent work

Chemistry teacher. To conclude our lesson, we invite you to do a little independent work. Each of you will receive a card with text. Using Table 1, try to determine what metal we are talking about; write its name instead of dots on the card. ( At the end of the work, students conduct a mutual check, the results are entered into the team table.)

VI. Summing up the lesson

Chemistry teacher. Our lesson is almost over. All that remains is to remember once again what you learned today, answer a few questions, draw a final conclusion and write it down in your notebook. (Students read the questions written on the board, answer them, discuss the conclusion, write it down in their notebooks.)
The biology teacher sums up the lesson, announces the total points for the teams, comments on the individual work of the students, and gives grades based on the number of tokens.

“Everything is chemistry” is an expression that can most often be heard from chemistry teachers at school, however, it is correct. Because, ultimately, absolutely everything consists of chemical elements. Our body too.

1. Oxygen. Not only is it an essential part of the air and drinking water we breathe, it also occupies a significant place in our body. With 65% of our body's total mass, oxygen is the most important chemical element within the human body.

2. Carbon boasts not only the largest number of chemical compounds in the periodic table (the most famous of them are coal and oil). He also takes an honorable second place on our list.

3. Hydrogen, like oxygen, is a component of air and drinking water. And it also refers to the basic components of the human body. 10% of our weight is made up of hydrogen.

4. Although nitrogen is also found in the air, it is better known as a coolant in liquid form. However, its mysteriously evaporating gases should not be misleading - 3% of our body mass consists of nitrogen.

5. Even if it is only 1.5%, calcium is an important metal in our body. It is what gives strength to our bones and teeth.

6. Phosphorus, as a luminous substance, is known to everyone. But not everyone knows that it is thanks to phosphorus in the body that DNA, the basis of human life, is formed.

7. Potassium, with a modest 0.2%, takes little part in body processes. It belongs to the electrolytes that our body needs primarily during sports. Its deficiency can cause feelings of exhaustion and cramps.

8. Could sulfur, with its unpleasant appearance and smell, be important for our body? Yes, that's exactly it. Sulfur is an essential component of amino acids and coenzymes.

9. First sulfur, now chlorine. You might think that our body consists of only poisons. Of course, there is no elemental chlorine in our body, but there is chloride. And it is vitally important for us, since it is contained, for example, in blood plasma.

10. We consume sodium primarily in the form of sodium chloride, also known as table salt. The element is important for the protection of cells and the movement of nerve signals.

11. Magnesium is vital for all organisms on earth, naturally, for us people too. Despite its insignificant part - 0.05% of our body weight, a lack of magnesium leads to clearly noticeable consequences: Nervousness, headaches, fatigue and muscle cramps are just some of them.

12. The male body contains more iron than the female body. One of the reasons that's the difference in nutrition. Another is that women lose iron during menstruation. Therefore, the average mass of this element in the human body varies from 2 to 5 grams.

13. Cobalt is a component of vitamin B12, which is essential for human existence. An overdose of cobalt leads to numerous diseases, including cancer.

14. Copper is lethal for microorganisms even in small quantities, but humans need it for the formation of vital enzymes. Heavy metal makes up 0.05% of our body weight. We get it through vegetables, chocolate and nuts.

17. Selenium is an essential micronutrient. At the same time, in case of an overdose, it is highly toxic, so its use as a dietary supplement causes great debate in scientific circles.

18. To this day, it has not been fully clarified how necessary fluoride is for our body. An indisputable fact is that most fluoride is found in bones and teeth. Fluoride, like selenium, is highly toxic in overdose

Every educated person should know what does the human body consist of. At least in general terms. After all, everyone has their own appeal, since this is information about us.

Human tissue

Cells that are identical in structure and function form tissues. There are four types of tissues in our body.

Epithelial tissue

Epithelial tissue (integumentary tissue) forms the skin and mucous membranes of internal organs.

Its main function is to protect the body and individual organs from external influences and actively participate in the metabolic process.

Epithelial tissue cells in the intestines, for example, absorb nutrients.

Connective tissue

From connective tissue consists of blood, lymph, bones and fat. Some cells of this type of tissue carry nutrients throughout our body, others (osteocytes) serve as support for the body, and others form the basis of the human defense system.

Muscle tissue

The name of muscle tissue speaks for itself. The word “muscle” comes from the Latin “musculis”, which in turn comes from the word “mus”, which means mouse.

And indeed, when contracting, our muscles seem to run under the skin. Long cells (up to 12 cm) contain the thinnest filaments that can contract - these are myofibrils and myofilaments.

Nervous tissue

Nervous tissue consists of very special cells called neurons.

They contain a body, where the nucleus is located, and processes (axons and dendrites). The length of the axon, a long process, can reach 1.5 meters.

A weak electrical discharge passes through it from cell to cell. It's called a nerve impulse.

Did you know that the smallest cell in the human body is the red blood cell? Its diameter is about 7 microns (1 micrometer is 0.0001 centimeters).

And the largest cell is the egg. Its diameter is about 0.1 mm. It can be seen even with the naked eye.

If you like interesting facts about everything - be sure to subscribe to any social network. It's always interesting with us.

Microelements are chemical elements contained in plant and animal organisms in small quantities (in thousandths or less of a percent, and in some cases, hundredths of a percent). Microelements that are contained in organisms in quantities of one hundred thousandths of a percent or less (for example, gold, mercury) were called ultraelements by V.I. Vernadsky. Some of the microelements are necessary for the life of all organisms, others - for certain species, the significance of some has not yet been clarified. To carry out basic life functions, plants need copper, boron, molybdenum, manganese and zinc. Some plant species also require silicon, aluminum, titanium, vanadium, chromium, osmium, cobalt, nickel, arsenic, iodine, fluorine, gallium, lithium, beryllium and selenium. Animal organisms need copper, cobalt, zinc, manganese, iodine, fluorine, silicon and bromine. Arsenic, aluminum, nickel, barium, beryllium, lithium, rubidium, strontium, titanium, cadmium, molybdenum and vanadium play an important role in the body of some animal species. In addition, scandium, germanium, zirconium, antimony, tin, silver, cesium, lanthanum, mercury, tungsten, gold, thallium, lead, bismuth, cerium, radium, thorium and other microelements, the significance of which is not yet known, are found in the organisms of plants and animals. clarified.

The content of many microelements in individual tissues and organs of plants and animals has not yet been sufficiently studied. It is known that the blood of a number of vertebrates contains 24 microelements. Some of these trace elements (for example, copper, zinc, manganese, tin, cadmium, lead) are concentrated in formed elements, others (for example, titanium, cobalt, silicon, aluminum) are concentrated in blood plasma.

15 trace elements (copper, zinc, manganese, lead, titanium, molybdenum and others) were found in the mammal's brain. Some trace elements accumulate in certain organs and tissues: gonads (zinc), pituitary gland (zinc, chromium), pancreas (zinc, nickel), spleen of embryos and placenta (cobalt), liver of embryos and newborns (copper), kidneys (cadmium ), lungs (lithium), retina (barium), vitreous body of the eye (silicon) and others. Selective concentration of microelements by individual tissues and organs can be very significant.

Trace elements are part of a number of compounds that have a special function: enzymes, for example carbonic anhydrase (zinc), mono- and polyphenoloxidases, as well as formicodehydrase (copper), arginase (manganese); vitamins, such as vitamin Bi (cobalt); hormones, such as thyroxine (iodine), insulin (cobalt, zinc); respiratory pigments, such as hemocyanin (copper). Microelements were also found in a number of compounds whose role in the body has not yet been clarified (for example, zinc compounds with phosphatides in plants, zinc and manganese compounds with proteins in invertebrate animals, protein compounds of copper and cobalt in vertebrates).

Object of study: human body.

Subject of research: the influence of microelements on physiological processes in the human body.

Fundamental question: trace elements: evil or good?

Purpose of the work: using various sources of information to study the physiological effects of some microelements on the human body.

Job objectives:

Study the literature on this issue

According to the method of M. Hamm and A. Rossmeier, conduct a study of the content of calcium, potassium, and iron in the human body.

Chapter 1. Chemical composition of the human body

English scientists calculated the daily consumption of various elements with food. It turned out, for example, that a resident of Great Britain daily absorbs 5400 mg of chlorine and 4600 mg of sodium, 23.2 mg of iron, 0.32 mg of lead, 0.3 mg of silver and antimony, 0.01-0.001 mg of gold, 0.001-0 each. .0001 mg of platinum and uranium. In total, the daily ration for 40 elements was determined.

The figures, of course, are averaged, referring to the average “capita”. There are bound to be big differences in the daily 'micronutrient menu' for 60 million Brits. In addition, each of them has a different menu in summer and winter, on weekdays and holidays.

Of course, for the inhabitants of other areas - Java, Tibet or Sudan - the daily diet of microelements will look different.

And what does a person himself consist of? What chemical elements are included in the tissues of his body and in what quantities?

Academician V.I. Vernadsky was very interested in this problem. He summarized all the materials available in the early 20s. , and in 1922 In Petrograd, his brochure “The chemical composition of living matter in connection with the chemistry of the earth’s crust” was published. There was a table placed there, the numbers of which answered the question: what does a person consist of?

Three quarters by weight are oxygen and hydrogen. The German physiologist Emil Dubois-Reymond was right when he called man “Animated Water.” If we add carbon, calcium and nitrogen here, then the share of five elements accounts for 97.4%. Dozens of other chemical elements taken together make up 1/40 of a person's weight, but they are present everywhere, penetrating his flesh, brain, and blood.

The composition of humans is close to the average composition of living matter. This is not surprising, because humans are omnivorous creatures.

In me. and long threads of fur, and fruits, and grains, and roots suitable for food, I am all filled to the brim with four-legged animals, I am all filled with birds.

In old popular publications there are calculations like the following: the lime contained in the human body is enough to whitewash a chicken coop, iron is enough for a medium-sized nail, phosphorus is enough for 2200 matches, etc.

Sixty years ago, V.I. Vernadsky wrote about the presence of 24 elements in the human body.

Now we know that the presence of 43 elements has been established in a human tooth, and, in addition, another 25 elements can be found in dental tissue. (In reality, according to the law of universal dispersion, teeth must contain all the chemical elements found in earth's crust. Some of them are simply not yet determined due to very low concentrations.)

In 1964, the quantitative content of 78 elements was established in blood serum. Note that the blood of healthy people of average age 35 years was studied; they were all Red Cross donors. It's easier to say what's not in the blood. There are no noble gases, transuranium elements and elements numbered 84-89 (polonium, astatine, francium, radium, actinium).

The blood is salty. It has long been noted that there is a striking similarity in the composition of human blood and sea water.

If we compare the ionic composition of these two liquids, then in the blood the share of sodium and chlorine is 76.2%, and in sea water - 85.7%. For potassium, the figures will be 2.3 and 1.1%, respectively, and the calcium content in both cases is the same - 1.2% each. Similar values ​​were also noted for other elements. This similarity is not accidental. It constantly reminds us of those hypotheses according to which the origin and development of life occurred in the ocean.

Of course, any determination of the content of trace elements in the human body, based on blood, muscle or bone tissue etc., is nothing more than a kind of “snapshot”, “freeze frame”. After all, those several dozen elements, the presence of which is established in the human body, are in continuous movement - they enter the body, remain in it, linger, accumulate, and leave it. Some microelements are slow, others are hasty. This whole motley and time-varying (within certain limits) picture is associated with metabolic processes, the composition of food and water, the composition of inhaled air, and depends on the age and individual characteristics of the body.

So, almost the entire periodic table is in a piece of rock, in a lump of humus, in a daily lunch, in a drop of blood and in a drop of sea water, in a meteorite speck of dust! V.I. Vernadsky called this distribution of the element a “microcosmic mixture” (in small doses everywhere).

Yes, you can find something in common in the composition of humans and reeds! But, on the other hand, by carefully comparing the composition of two organisms, one can always notice elements whose concentration differences are very large. In percentage terms, a person contains 34.5 times more calcium and 40 times more iodine than cane, but 20 times less nickel. Cane contains 80 times more iodine than alfalfa.

So, when comparing the chemical composition of different living organisms, contradictory features that are in dialectical unity are revealed. The content of the predominant elements - oxygen, hydrogen and carbon - is always characterized by close numbers. But differences in the concentration of individual microelements can be very significant, which gives each species chemical uniqueness.

“It seems to us that the position is indisputable that the chemical composition of an organism is its sign - species, generic, etc.,” writes academician A.P. Vinogradov.

Among the elements of the periodic table, 21 biophiles are distinguished, i.e., such elements that are necessarily included in the composition of any living organism (theoretically, based on the law of microcosmic scattering, we must assume the presence of all elements known on Earth in any organism. Those elements that are analytically Today they are not detected, they are present, apparently in very small concentrations). These are, first of all, oxygen, hydrogen, carbon, nitrogen and sulfur - the magnificent five from which protein molecules are formed. This is followed by the very widespread phosphorus, chlorine, magnesium, potassium, sodium and iron. The remaining 10 belong to trace elements: iodine, boron, cesium, vanadium, manganese, copper, zinc, molybdenum, cobalt and selenium. Biophiles are part of any living creature, be it a person, a pine tree or a hermit crab. Without them, life is impossible. Other microelements, although not as universal as the ten mentioned, also significantly influence the development of life, despite more than modest, often almost imperceptible concentrations.

At the same time, their quantitative content in the body is by no means indifferent. The same element (even a biophile), depending on its concentration, can be both beneficial and harmful and may deserve both a word of praise and a fair accusation.

Chapter 2. Chemistry of microelements and human health

2. 1. Alkali metals and human health

Sodium and human health

Biological role of sodium

Maintains the constant osmotic pressure of the blood, necessary for the normal functioning of tissue cells. Participates in the regulation of water metabolism, since sodium ions contribute to an increase in water consumption and the binding of water in the body, as well as an increase in blood pressure.

Activates digestive enzymes, regulates the functioning of nervous and muscle tissues. Sodium metabolism is controlled by adrenal hormones, which promote sodium and water retention in the body.

Sources of sodium in the human body

1. Food products. The natural sodium content of foods is relatively low.

The daily requirement for sodium is 1-2 g.

2. Eating foods prepared with table salt.

The body's response to sodium deficiency

Sodium deficiency can occur with prolonged vomiting or diarrhea, which will lead to a decrease in blood volume and low blood pressure. Sodium absorption decreases with heavy sweating (in hot climates), as well as with heavy physical exertion.

The body's response to excess sodium

Since sodium has the ability to bind water in the body (1 g of table salt can bind up to 100 ml of water), the body experiences thirst. Everyone knows how thirsty you feel after drinking salt water. When tissues and blood vessels are oversaturated with table salt, excess water occurs, which leads to overload of all organs. The kidneys are the first to suffer (when urine is formed, they process blood with a high sodium content). As a result, swelling of the legs and face occurs.

The heart also suffers, as it is forced to work with greater load.

Limiting salt intake is also advisable in the last months of pregnancy.

Research in London has shown that eating too much salt can lead to a life-threatening condition for people with asthma. It is important to control salt consumption in case of a disease such as hemorrhoids, since when it is consumed in excess, the liquid remains in the circulatory system, which contributes to the swelling of the veins in the anus.

In people suffering from osteoporosis (bone loss), with a high sodium content in food, there is a greater release of it, and with it calcium, an element so necessary for the body.

It is known that in ancient times people did not add salt to food. At the dawn of humanity, it was worth its weight in gold, and tribute was paid with it. The great Plato called salt a gift of the gods. Man began to use table salt in food only in the last 1-2 thousand years, first as a flavoring seasoning, and then as a preservative. For thousands of years, people have used salt, unaware of the insidiousness of the pretty white crystals. (It is known that many peoples of Africa, Asia and the North still do without salt.). Calvin Smith, an ordinary factory doctor at one of the Ford plants in Detroit, did not suspect this either. Regularly examining workers, Smith found that for some, blood pressure was always normal, for others it periodically jumped, and for others it became higher and higher from year to year (the latter were treated by the doctor for hypertension).

Ford, as you know, was the first in the world to introduce a conveyor belt at his factories, and during a common lunch break, thousands of workers sat down at the table, receiving standard portions of the same food. Being present in the canteen on duty, Smith noticed that some workers never used the salt shaker, other workers tried the food and sometimes added salt, while others, without trying, always added salt. For the time being, the doctor automatically recorded these habits of the workers, but one day it dawned on him: those who never salted their blood pressure remained normal for many years, and those who always added salt to their food included his patients with high blood pressure. This is how the world learned that excess salt in food causes hypertension.

About 50% of all hypertensive people react to salt because they are salt-sensitive, meaning their blood pressure changes markedly when salt intake is increased or decreased. Such salt sensitivity, according to most representatives of medicine, is hereditary. It is more pronounced with excess body weight and is more often observed in older people.

Salt sensitivity also occurs in people considered to be generally healthy with regard to blood pressure.

Abuse of salt over many years can provoke hypertension in them.

Limiting salt intake should be gradual, over 2 or 3 months, while adhering to the following steps:

1. Taste your food before adding salt.

2. Remove the salt shaker from the table.

3. Use less salt when preparing food. To begin with, limit ¾ of your usual amount. Then add half as much salt.

4. Add herbs, pepper, garlic, dry mustard, lemon juice, spices, and nutmeg to your food.

5. Limit your salt intake, which you get from prepared foods (canned soups, vegetables, meat, fish).

Potassium and human health

Biological role of potassium

Regulates the acid-base balance of the blood.

Participates in the transmission of nerve impulses.

Activates the work of a number of enzymes.

It has protective properties against the unwanted effects of excess sodium and normalizes blood pressure. In the body of people who eat a lot of potassium-rich vegetables - vegetarians - the amount of potassium and sodium are in balance. These people most often have lower blood pressure than their meat-loving fellow citizens.

Has an antisclerotic effect.

Potassium has the ability to enhance urine formation.

Potassium enters the body with food. Its daily intake is 1400-7400 mg. The best source of potassium is plant foods. These are watermelons, melons, oranges, tangerines, bananas, dried fruits (figs, apricots, rose hips). Berries rich in potassium include lingonberries, strawberries, black and red currants. There is a lot of potassium in vegetables (especially potatoes), legumes, wholemeal products, and rice.

The body's response to potassium deficiency

With a lack of potassium in the body, muscle weakness, intestinal lethargy, and cardiac dysfunction are observed. Sudden death may occur with increased loads. There is poor transmission of nerve impulses. Diuretics (diuretics) reduce potassium absorption. When preparing food, it is necessary to pay attention to the fact that potassium compounds are water-soluble. This circumstance requires you to wash products containing it before chopping them and cook them in a small amount of water.

The body's response to excess potassium

With an excess of potassium in the body, the main functions of the heart are inhibited: a decrease in the excitability of the heart muscle, a slowdown in the heart rate, deterioration of conductivity, and a weakening of the force of heart contractions. In high concentrations, potassium ions are present. called cardiac arrest in diastole (phase of contraction of the ventricles of the heart). The toxic dose of potassium is 6 g. The lethal dose is 14 g. Potassium salts can be toxic to the body due to the anion associated with the potassium ion, for example, KCN (potassium cyanide).

Did you know that

Traditional medicine believes that the passionate desire to drink alcohol is associated with a lack of potassium in the body.

2. 2. Calcium and human health

Biological role of calcium

It is a “building material” for the formation of bones and teeth.

Important for regulating the processes of growth and activity of cells of all types of tissues.

Affects metabolism.

Important for the normal functioning of the muscular and nervous systems.

Ensures normal blood clotting.

Has an anti-inflammatory effect.

Provides the body's resistance to external adverse factors.

Sources of calcium in the human body

Calcium comes from consuming milk, dairy products, and cheeses. Good sources of calcium are egg yolk, cabbage, soybeans, sprats, parsley, etc.

The more calcium enters the body with plant foods and cereals, the better the condition of bone tissue. Eating animal fats and drinking water contribute to the intake of calcium into the human body.

The body's response to excess calcium

Excessive intake of calcium into connective tissue cells partially dehydrates them, as a result of which the cells wither and their physiological activity decreases. This leads to increased excitability of the nervous system and the development of urolithiasis. With excessive ingestion of calcium salts, hypercalcemia develops, which leads to the deposition of salts in various tissues and organs.

The body's response to calcium deficiency

A decrease in calcium concentration in the body leads to a decrease in the excitability of the nervous system, resulting in the appearance of seizures. If a negative calcium balance persists for a long time, calcium deficiency phenomena such as osteoporosis may occur.

The most vulnerable and susceptible to injury are the spine, femoral neck, and wrist.

WITH therapeutic purpose Prescribe calcium supplements, which are recommended to be taken with milk.

Osteoporosis, according to the World Health Organization, ranks 4th among other diseases common on Earth, second only to diseases of the cardiovascular system, cancer, and endocrine diseases.

Osteoporosis occurs as a result of a slow and silent loss of calcium, resulting in a decrease in bone volume and strength. Women with fair skin, women who smoke, and drinkers of alcohol and coffee are more susceptible to osteoporosis.

In order for bones to remain hard, a balanced exchange of calcium must occur between them and the blood, promoting constant self-renewal of bone tissue. It is this continuous process of bone self-repair that is supported by estrogens and other hormones.

As estrogen levels in a woman's body decrease with age, bones lose their ability to retain calcium. They become thinner and lighter to such an extent that they become sponge-like.

The concentration of calcium in the blood is controlled by parathyroid hormones. This hormone causes the absorption of calcium in the intestine, its release from the bones and its reabsorption from primary urine in the renal tubules.

Did you know that

Blood with low calcium content does not clot when exposed to air.

If the food of the expectant mother is saturated with calcium and magnesium, then the female sex predominates in the offspring, and excess calcium leads to the fact that she gives birth to predominantly male offspring.

In areas where natural water contains increased amounts of calcium and magnesium ions, so much scale accumulates in every home over the course of a year that it can fill a trash can.

2. 3. Halogens and human health

Chlorine and human health

Biological significance of chlorine

Maintains normal osmotic pressure of blood plasma, lymph, and cerebrospinal fluid.

Participates in the formation of hydrochloric acid, metabolism, and tissue construction.

Necessary for cell disinfection.

Helps get rid of excess weight.

Dissolves deposits on joints.

Sources of chlorine in the human body

Chlorine should enter the body daily in an amount of 3-6.6 g with plant and animal foods, and not in the form of table salt (sodium chloride), because the latter leads to alkalization of the body, thickens the blood and causes diseases of the cardiovascular system. CO2 enters the stomach from venous blood and a reaction occurs: enzyme

CO2+H2O+Cl- → HCl (stomach)+HCO-3 (blood).

This reaction is enzymatic, and the enzyme catalyzes its occurrence towards the formation of hydrochloric acid.

The body's reaction to chlorine deficiency

Disturbances in chlorine metabolism lead to the development of edema, insufficient secretion of gastric juice, etc. A sharp decrease in chlorine content in the body can lead to a serious condition, even death.

The body's reaction to excess chlorine

Excess chlorine in the body causes diseases of the gastrointestinal tract, headaches, and general metabolic disorders.

An increase in its concentration in the blood occurs when the body is dehydrated, as well as when the excretory function of the kidneys is impaired.

Chlorine is excreted mainly through urine (90%) and sweat (6%). The chlorine content in urine depends mainly on its content in food. Of interest is the ability of chlorine, when ingested in excess, to be deposited in the skin, retained in the body, and excreted through sweat in significant quantities.

Cl2 gas is very toxic.

Use of chlorine

Chlorine is used in medicine for disinfecting objects, premises and in public utilities for chlorinating water, since it has a strong disinfectant effect due to its oxidizing properties. The same properties are exhibited by chlorine water (a solution of chlorine in water) and bleach Ca (OCl)2. The action of these agents is based on the fact that in aqueous solutions of these substances there is an acidic environment in which proteins coagulate, and during the reaction of Cl2 with H2O and during the hydrolysis of Ca (OCl)2 in the presence of CO2, a strong oxidizing agent is formed - hypochlorous acid HclO. This acid decomposes in the light into HCl and atomic oxygen O, which is a strong oxidizing agent and destroys the structure of cells, and microorganisms die.

Since chlorine has a bleaching effect, it is used in the pulp, paper and textile industries.

Hydrochloric acid and human health

Gastric juice, along with other substances, contains hydrochloric acid. Its mass fraction is 0.4-0.5%. At this concentration, HCl is detrimental to living foreign cells: thus it performs a protective function and prevents the development of microflora in the stomach. However, HCl does not affect the cells of the stomach itself. The pH value of gastric juice is 1.6-1.8% (acidic environment) (see for yourself by examining the gastric juice with litmus paper). Gastric juice contains enzymes, one of them is pepsin. When the secretion of gastric juice does not occur, pepsin is in an inactive form - in the form of pepsinogen. Then, under the influence of HCl, which is part of the gastric juice, pepsinogen is converted into pepsin, which breaks down proteins into amino acids. Pepsin acts only in an acidic environment. Hydrochloric acid increases pancreatic secretion. Under the influence of acid, the transition of stomach contents to the duodenum is delayed. The acidity of gastric juice can be examined by taking a sample on an empty stomach or after a test breakfast. The acidity of gastric juice can be normal, zero, low or high.

Zero solubility – no free hydrochloric acid.

Low acidity – too low concentration of acid in the stomach. People suffering from a low level of HCl in gastric juice are more at risk of contracting infectious diseases, since HCl has a bactericidal function; This makes it difficult to digest protein foods. Low acidity can be accompanied by stomach cancer, chronic constipation, and inflammation of the stomach. Such people are prescribed gastric juice (natural or artificial). Means that increase the concentration of hydrochloric acid include carbonated mineral waters, strong tea, black bread, vegetable and fruit juices, various spices (horseradish, mustard, etc.).

Increased acidity – excess hydrochloric acid in the stomach. Often accompanied by gastric ulcer and duodenum. A sign of a stomach ulcer is mild pain in the middle part of the abdomen, always associated with eating.

Sometimes they occur immediately, sometimes after 2-3 hours, or even 5-6 hours after eating (hungry pains). The disease usually begins sluggishly, its attacks alternate at fairly long intervals; exacerbations in spring and autumn. The most serious complication is perforation of the ulcer. The patient feels a dagger-like pain. It is caused by the fact that the ulcer, which has captured all layers of the stomach wall, breaks through, and its contents end up in the peritoneal cavity. In this case, urgent surgery is needed.

One of the signs increased acidity is heartburn. A characteristic burning sensation occurs. It usually goes away if you drink a little alkaline mineral water“Borjomi”, “Essentuki”, No. 4, No. 17 (the water should be heated a little to remove carbon dioxide). To prevent the disease, proper diet, giving up bad habits, observing work and rest schedules, and avoiding stress and conflict situations are of great importance.

In ancient Greece, doctors used dried coral powder to treat heartburn and stomach pain. The main component of corals, calcium bicarbonate Ca(HCO3)2, reacted with hydrochloric acid and neutralized it.

Medicinal substances “antacids” that neutralize the hydrochloric acid of gastric juice, the “progenitors” of which were corals, received their name in connection with the direction of this reaction: from the Greek. “anti” - against and lat. "acidus" - sour.

Antacids as a component of the treatment of gastric ulcers attracted the attention of doctors only at the beginning of the 20th century. The first modern drugs of this group were sodium bicarbonate NaHCO3 - baking soda 0 and calcium carbonate CaCO3 - chalk. However, medications containing soda and chalk have many side effects. For example, as a result of the reaction of sodium bicarbonate with hydrochloric acid, a large amount of carbon dioxide is released:

NaHCO3+HCl = NaCl + H2O + CO2.

Carbon dioxide, dissolving in water, produces carbonic acid, which stimulates the glands of the stomach and provokes a new release of hydrochloric acid. For this reason, bloating and belching after taking such medications are replaced by a new attack of pain and heartburn.

Further research was aimed at developing drugs that are not absorbed in the gastrointestinal tract. Such drugs, which include aluminum hydroxide Al(OH)3 and oxide (or magnesium hydroxide) MgO (Mg(OH)2), absorb hydrochloric acid without releasing carbon dioxide and remove it from the body “in transit”, passing through the gastrointestinal tract. intestinal tract. Aluminum hydroxide has a fixing effect, and magnesium oxide or hydroxide has a laxative effect. In the non-absorbable antacid "Maalox", the ratio of aluminum and magnesium is selected in such a way as to avoid these troubles.

Al(OH)3 + 3HCl = AlCl3 + 3H2O,

MgO + 2HCl = MgCl2 + H2O.

Cabbage, cabbage and potato juice are used as a preventive or additional remedy in the treatment of peptic ulcers. This was practiced back in Ancient Rome, because cabbage contains anti-ulcer vitamin U (from the Latin “ulcer” - ulcer).

Iodine and human health

The iodine content in the human body (body weight 70 kg), according to some data, is 25-30 mg. Of this amount, 15 mg. Located in the thyroid gland. It is located on the front surface of the neck and has the shape of a butterfly - two lobes and an isthmus. In normal condition it should not be visible. The absorption of iodine by the body occurs quite quickly in the stomach. It enters the thyroid gland through the bloodstream.

Biological role of iodine

Iodine is necessary for the normal functioning of the thyroid gland. The thyroid gland produces the hormones thyroxine and triiodothyronine, the synthesis of which requires iodine. Without iodine, thyroid hormones, which control the rate of metabolism in the body, cannot be formed.

The entire volume of blood circulating in the body passes through the thyroid gland within 17 minutes. If the thyroid gland is provided with iodine, then during these 17 minutes. Iodine kills unstable microbes that enter the bloodstream through damaged skin, the mucous membrane of the nose or throat, and when food is absorbed in the digestive tract. Persistent microorganisms, when passing through the thyroid gland, become weak until they finally die, provided that it is properly supplied with iodine. Otherwise, microorganisms circulating in the blood remain.

Iodine has a calming effect on the body and nervous system. With nervous tension, irritability, and insomnia, there is a need for iodine to relax the body and its optimistic mood. With a normal supply of iodine to the body, an increase in mental activity is observed.

Iodine is one of the best oxidation catalysts in the body. With its deficiency, incomplete combustion of food occurs, which leads to the unwanted formation of fat reserves.

Iodine restores human energy.

Sources of iodine in the human body

Sources of iodine entering the body are iodine-containing mineral waters, food (sea fish), sea air and sea water. The intake of iodine decreases when eating cabbage and cauliflower.

The body's response to iodine deficiency

With insufficient intake of iodine in the body, the function of the thyroid gland decreases and hypothyroidism develops. With a lack of iodine, children experience growth retardation, physical development, and profound mental retardation.

With a lack of iodine in adults, the symptoms of a lack of thyroid hormones are a decrease in metabolism, a drop in body temperature, hair loss, lethargy, and weakness.

Iodine deficiency is compensated by taking iodized table salt, which contains potassium chloride (25 g per 1000 kg of salt).

Did you know that

Diseases associated with iodine deficiency have been identified by the World Health Organization as a global problem, ranking alongside cardiovascular diseases and cancer.

In order to prevent thyroid diseases, you should never use an alcohol solution of iodine, as it is intended for other purposes.

With an excess of iodine in the soil, a weakening of the synthesis of iodine compounds in the thyroid gland is observed.

Ocean mullet and Japanese crucian carp contain so much iodine that they cannot be eaten due to their medicinal smell.

2. 4. Iron and human health

The iron content in the human body (body weight 70 kg) is, according to some sources, 3.5 g. The distribution of iron in the human body (as a percentage of the total mass of iron) is shown in Appendix 1. A small part of the iron is spent on the growth of the integumentary tissues of the body - the skin and nails. Iron is part of the pigment that colors hair (red hair contains 5 times more iron than any other hair). As can be seen from the data in Appendix 1, the bulk of iron is found in the blood - red blood cells. This became known thanks to the discovery of the Frenchman Mary in the 19th century. Erythrocytes are red blood cells, the main function of which is to carry out gas exchange between the body and environment, i.e., red blood cells carry oxygen in the body that comes in during respiration.

Being part of the iron-containing pigment - hemoglobin, iron determines the red color of this substance, as well as the color of blood. The hemoglobin molecule consists of two parts: a protein - globin (the main part of the molecule, which has a different structure in different living organisms) and an iron-containing group - heme, which is the same in all organisms. The hemoglobin molecule contains four hemes and each contains one iron atom; they account for only 0.35% of the mass of the huge molecule.

It is iron that helps capture oxygen and* release it where it is needed. There are ~25 trillion red blood cells circulating in the human body (they contain most of the total iron in the body), thanks to which we can breathe. The lifespan of red blood cells is 3-4 months, after which, having fulfilled their function, they are destroyed.

The “production” of new red blood cells is a function of the hematopoietic organs, the main one of which is the bone marrow.

In a healthy person, he produces ~200 billion red blood cells every day, for an average human life(70 years old) they enter the blood in an amount of 5 * 10 with a total mass of -500 kg. Each of this myriad of red blood cells needs to be “charged” with hemoglobin, and therefore with iron. To prepare 0.5 tons of red blood cells, approximately 0.5 kg of iron is required. However, the intake of iron into the body from food is measured in a few milligrams per day, tens of grams over the entire human life.

Sources of iron in the human body

Iron enters the body with food.

In order for iron to be absorbed, it undergoes complex transformations. In food products, iron is in trivalent form. The cells of the intestinal mucosa allow iron to pass through in divalent form - in the form of iron (II) chloride salt FeCL2 or iron (II) sulfate FeSO4. It is divalent only in special medications. Having passed the esophagus and entered the stomach, ferric iron is reduced to divalent iron under the action of gastric juice. The most important role in this process is played by hydrochloric acid and other substances that make up the gastric juice. Therefore, with low acidity, iron supplements are prescribed along with hydrochloric acid or gastric juice. Of all the iron that is in food, 2-20% is absorbed, and it is also important that only 2-8% of iron is absorbed from products of plant origin. In animal products, iron atoms are part of protein molecules, which facilitates its absorption.

Affects iron absorption and food composition. Vitamin C and fructose (found in vegetables, fruits, juices, honey) create favorable conditions for the absorption of iron, since they form highly soluble compounds with it. B vitamins play an important role. However, in addition to “friends,” iron also has “enemies.” The “enemies” of iron are tea, coffee, dairy products and egg yolks. A cup of tea drunk during a meal will reduce the absorption of iron by almost 2/3, since it produces poorly soluble compounds. If coffee is drunk after a meal, then the body will miss 40% of iron, and if it is drunk 1 hour before a meal, it will leave the iron intact. If everything is in order with your iron, then you can safely eat foods that are considered “enemies” of iron. If not, then you need to change your lifestyle.

From the stomach, iron penetrates through the membrane into the cell of the intestinal mucosa. Here the protein apoferritin, which belongs to the group of gamma globulins, awaits him. It forms a complex water-soluble compound with iron - ferritin. During this reaction, iron changes its valency for the second time: in the composition of ferritin it is again trivalent. Apoferritin has a dual role. Firstly, it serves as a “conductor” of iron through the mucosal cell, and secondly, it regulates the flow of iron from the intestines. As soon as all the apoferritin present in the cell is “saturated” with iron and turns into ferritin, the absorption of iron through the membrane is blocked. This feedback mechanism protects the body from unnecessary excess iron.

The next barrier to iron is the membrane that separates the mucosal cell from the bloodstream. Iron bypasses this barrier and, entering the blood plasma, changes its valency for the third time: cleaved from ferritin, it again turns into divalent. Its “conductor” also changes: with the blood, iron carries another protein - transferrin - throughout the body. Finally, before being deposited in a particular tissue, iron again combines with protein, forming ferritin (which contains ferric iron), which is convenient for storing iron reserves.

So, iron, having entered the body, bypasses the esophagus and enters the stomach, where, under the influence of hydrochloric acid, gastric juice is reduced from trivalent to divalent. Further, in the intestine, part of the iron contained in food, on average -10% (the rest is excreted from the body), is absorbed through the mucous membrane and enters the blood, while changing its valence twice. Iron is carried throughout the bloodstream throughout the body and, once again oxidized into trivalent iron, is deposited in the tissues.

The iron cycle in the human body is shown in Appendix 3.

In water, iron is found in the form of Fe salts. GOST allows the iron content in drinking water to be up to 0.3 mg/l, and if there is no iron removal station, then up to 1 mg/l. If the iron content exceeds the specified value, then this negatively affects the organs of the digestive and cardiovascular systems.

The body's response to iron deficiency

The human body handles iron very carefully, but even in a healthy person, iron is gradually eliminated from the body: an adult man loses ~1 mg of iron per day. In women, losses are much greater, since the main reservoir of iron is blood. A lot of iron is carried away by bleeding, especially menstruation. Therefore, the need for iron in men is 0.9-1.2 mg per day, and in women 1.3-2.5 mg, during pregnancy up to 5 mg. If a person does not receive enough iron from food, reserve iron is consumed. For men, these reserves last for 2-3 years, even if there is not a single atom of iron in the food. In women, these reserves are 3 times smaller, so they develop iron deficiency much earlier.

When iron begins to be scarce and the body begins to use up its reserves stored in the liver, the liver responds to this with a sharp increase in the production of iron “conductors” - apoferritin and transferrin. The absorption of iron through the intestinal mucosa immediately increases: the body strives for every atom of iron and from the same food products absorbs 1.5-4 times more iron than usual.

And yet, these reserves may be insufficient if too little iron comes from food or its losses are too great: the disease iron deficiency anemia, or anemia, occurs.

There is a type of iron deficiency anemia that occurs in every person in the first year of life. In the first 6 months of intrauterine development, the fetus does not receive iron from the mother. Iron accumulation begins only in the last 3 months before childbirth. By the time of birth, a normal baby stores 250-300 mg, and a premature baby stores 100-150 mg. However, the rapid growth of a child requires enormous amounts of iron, the reserves of which are quickly depleted. This serves as a signal to the growing body that breast milk alone is no longer enough and that it is necessary to switch to a more varied diet. Very little iron enters the body with breast milk - in 100 g of human milk there is only 0.7 mg of iron, of which 0.02 mg is absorbed. The child’s need for iron is 0.5 mg per day, i.e. the child long time develops in conditions of severe iron deficiency. With mixed and artificial feeding, iron deficiency is even greater, because 2-3 times less iron is absorbed from cow's milk than from women's milk.

Back in the last century, doctors drew attention to anemia that affected girls in closed educational institutions. Signs of the disease: greenish-pale complexion, weakness, dizziness, fainting, poor appetite.

The brain requires a huge amount of oxygen to function, and with anemia, the brain does not receive it in the right amount. Anemia most often develops in adolescence, when puberty occurs. During this period, you especially need to monitor your diet so that it is rich in iron. For severe anemia, it is prescribed medicines containing iron. After taking these medications, you must rinse your mouth thoroughly, as darkening of the tooth enamel may occur. Iron supplements can cause irritation of the gastrointestinal mucosa, nausea, and vomiting. Because these drugs bind the intestines with hydrogen sulfide (a natural stimulant of peristalsis), they can cause constipation.

Ferrous (marcial) mineral waters of Siberia, the Caucasus and Karelia will help satisfy the need for iron. They got their name in honor of Mars - the god of war and the alchemical symbol of iron. These are “Darasut”, “Polustrovo” and others. Marcial water cannot be stored for a long time, because it contains FeSO4 * 7H2O, a compound that quickly undergoes oxidation. A brown precipitate of Fe(OH)3 precipitates from a clear solution of water.

The body's response to excess iron

If a large amount of iron suddenly enters the blood plasma, then such excess iron, unnecessary for the body, is also deposited in the tissues. In this case, a compound of ferric iron with proteins is formed, but in the form of a water-insoluble complex - hemosiderin. This compound can no longer be used by the body in the future. Its accumulation disrupts the functions of those tissues and organs where it occurs and leads to the development of the disease - hemosiderosis.

Did you know that.

Count A.P. Bestuzhev-Ryumin (1693-1766) - Chancellor of Empress Elizabeth and Field Marshal of Empress Catherine 11 - proposed drops, called “Bestuzhev’s”, as a strengthening and aphrodisiac. The drops were a solution of ferric chloride (111) in a mixture of ethyl alcohol and ethyl ether. Catherine often used them.

Hematogen is made from bovine blood and is used to prevent anemia.

It has been experimentally shown that in healthy men and women, a single intake of a moderate dose of alcohol causes increased excretion of iron, aluminum, and zinc through the intestines, which creates the preconditions for a deficiency of these metals in the body. - Tea contains tannic acid. If you mix a light infusion of tea with a solution of iron salt, it will turn black, because the tannic acid contained in tea combines with iron to form ink. This is why you should not brew tea in a metal teapot.

2. 5. Mercury and human health

Mercury is a cumulative poison that can accumulate in the body, mainly in fatty tissues, and causes deformities in children. The toxic dose is 0.4 mg, lethal - 150-300 mg.

Toxic properties of mercury

Unlike many substances that are in the gas phase in the form of two-, three-, and four-atomic molecules, mercury exists in the form of Hg atoms. Once in the lungs, mercury vapor penetrates the circulatory system and enters into a chemical interaction with enzyme proteins and biocatalysts that carry out thousands of chemical processes in our body. Some enzymes, having bound with mercury atoms, lose their catalytic properties, while others begin to accelerate reactions, the products of which are substances that poison the body.

One way or another, each of us deals with mercury. We all have to measure our body temperature. There may be a situation when, when measuring the temperature, the thermometer falls out of your hands and... breaks. Tiny droplets of mercury scatter on the floor.

Circumstances become more complicated if this happens in a room with parquet flooring: then droplets fall into the cracks between the planks. The concentration of mercury becomes approximately 100 times higher than the maximum permissible concentration.

In this case, it is necessary to perform a number of actions to prevent chronic poisoning of the inhabitants of the room:

1. Collect leaked mercury using copper (brass) wire (plate) or pieces of foil (“silver”, tin paper from candies). Liquid mercury, wetting it, will stick to the copper and tin surface. You can also use an ordinary medical bulb for this. After collecting the drops, the place where the mercury could linger should be covered with sulfur powder or aluminum dust, or filled with a solution of ferric chloride.

2. Place all the collected balls in a glass jar and take them to the nearest sanitary and epidemiological station.

3. Wipe the area where the mercury was located with a damp cloth, then wash your hands thoroughly (and throw away the cloth).

The danger of chronic mercury poisoning lies in the fact that a person does not show signs of health problems for a long time. At this time, the development of those biological changes occurs, the result of which are severe consequences, namely: increased excitability, acute headaches, general weakness, increased fatigue, progressive weakening of memory, fainting. Later, the hands, eyelids, and in severe cases, the legs begin to tremble. These signs of chronic mercury poisoning may be accompanied by loosening of the gums, loss of teeth and hair, and digestive tract disorders.

The bodies of children and women are more sensitive to the effects of mercury than the bodies of men.

Arab alchemists and doctors, who did not know about the harmful effects of being in a room with mercury, noticed that scorpions leave the home in which mercury was spilled. This is because scorpion enzyme proteins are different from human ones. Scorpion tissue molecules immediately “feel” the effect of mercury atoms, for example, on enzymes that ensure the respiration process. It would be nice for humans to have such an “early response alarm system” for the presence of mercury vapor in the air. In the meantime, chemists determine the insignificant content of mercury in the air of laboratories and industrial enterprises on the basis of sensitive color reactions.

Mercury is the only (under natural conditions) liquid metal that evaporates even at room temperature. Its vapors tend to spread evenly throughout the entire volume, being absorbed by fabrics, wooden products and materials of various designs. At temperatures above 28 C, mercury begins to evaporate and its vapors again enter the air. Therefore, its effect is comprehensive: it pollutes the soil, air and water.

If metallic mercury enters the human body for various reasons, no toxic effect is observed. The literature describes a case where several milliliters of mercury entered a person’s blood. For nine years, liquid mercury was detected by fluoroscopy in the ventricle of the heart and on the surface of the lungs. But there were no signs of mercury poisoning.

It is known that in the old days volvulus was treated by giving the patient a glass of mercury to drink. The bulk of mercury, having passed through the intestines, is excreted from the body, but droplets of it linger in the body without causing negative consequences.

The question arises: how to explain the fact that an inert metal, found in nature in its native form, which under normal conditions is not oxidized by oxygen, does not interact with water and alkalis, and does not dissolve in most acids (dissolves only in aqua regia, hot concentrated H2SO4) and suddenly exhibits toxic properties?

It is necessary to distinguish between the effects of metallic mercury, its vapors and salts.

The most toxic are Hg salts, for example sublimate HgCL2. If Hg salts enter the body, vomiting immediately occurs and a decline in cardiac activity occurs, a sharp drop in body temperature and fainting.

Metallic mercury is practically harmless to living beings, since the formation of divalent mercury ion, which can cause poisoning, does not occur in the body.

The toxicity of mercury vapor is explained by a change in the chemical properties of the substance when it is crushed, in the extreme case - atomization of the substance, which is a very effective way to increase its chemical activity.

Monovalent mercury compounds are less toxic than divalent mercury compounds.

Compounds of monovalent mercury have low solubility in water; compounds of divalent mercury, on the contrary, are water-soluble.

Finding mercury in living organisms

Young animals contain less mercury than older animals. There is more in predators than in the objects they feed on. Particularly “distinguished” fish - tuna - contain up to 0.7 mg/kg or more. It follows that predatory fish should not be abused in the diet. In Japan, industrial waste is dumped into the river. Agano and Minamata Bay led in the 1960s. to the enrichment of fish, crabs and oysters with mercury. Eating them caused severe poisoning of local residents. Fishing in the bay is still prohibited, since ~600 tons of mercury lie on the bottom of the sea. The “storage” of mercury is the kidneys of animals (up to 0.2 mg/kg). But if, when preparing kidneys, you soak them repeatedly, changing the water, and boil them twice, you can reduce the mercury content by about 2 times.

In plant products, mercury is found most in nuts, cocoa beans and chocolate (up to 0.1 mg/kg). In most other products, the mercury content does not exceed 0.01-0.03 mg/kg. With food, a person receives 20 mcg per day. Mercury, once in the body, concentrates in the kidneys and disrupts their normal activity.

Since 1819, amalgam (an alloy of mercury with some metal, most often silver, tin or copper) has been used to fill teeth. And to this day it remains the best material for treating some cases of caries. German dentists have found out how it affects the human body. It turned out that ~5 mcg of mercury leaks into the body from the filling per day. This amount is safe compared to how much it enters the body through active and passive smoking.

Acute poisoning occurs when mercury preparations are taken orally. Symptoms of poisoning are due to:

Irritating and cauterizing effects of mercury compounds on the gastrointestinal tract;

Absorption (resorption) of mercury ions;

The effect of mercury on the excretory organs.

The irritating and cauterizing effects of mercury preparations on the mucous membranes of the gastrointestinal tract develop soon after taking the drugs orally. In this case, a metallic taste and a burning sensation in the mouth, abdominal pain, nausea and vomiting (often mixed with blood) appear, and salivation increases. In the first hours of poisoning, shock may develop due to severe irritation of the gastrointestinal tract and the occurrence of acute pain in it.

Absorption of mercury ions occurs already in the first hours of poisoning and affects the central nervous system (initially there is its excitation, convulsions, then its depression), disturbances in the functioning of the cardiovascular system are observed (heart weakness, falling blood pressure, weak and frequent pulse) and kidney function (initially increased, then decreased urine output). Mercury ions are absorbed primarily by the mucous membranes of the digestive tract and kidneys, and therefore victims develop stomatitis, ulcerative colitis and kidney damage.

The effect of mercury ions on the excretory organs develops on the 2nd - 3rd day from the moment of ingestion of the poison.

Help with acute poisoning with mercury preparations

1. Take measures to remove the poison and prevent its absorption from the gastrointestinal tract. To do this, the victim must be given milk or egg white (to bind mercury with protein).

2. Carefully rinse the stomach with water and activated charcoal. Take orally activated carbon and saline laxative (magnesium sulfate).

H. To prevent the absorption effect of mercury ions, it is recommended to begin parenteral (for example, by injection) administration of antidotes (antidote) as early as possible.

Did you know that.

In the last century, about 120 people who gilded St. Isaac's Cathedral in St. Petersburg were fatally poisoned.

The domes were gilded by rubbing the metal roof with gold amalgam - a solution of gold in mercury. The fatal poisoning was caused by mercury vapor that workers breathed daily. This happened because workers and management were poorly aware of the toxic properties of mercury and did not pay attention to the symptoms of the onset of poisoning: lack of appetite, headaches and stomach upsets.

In the Middle Ages, mercury poisoning was called “the mad hatter’s disease,” because craftsmen who used mercury preparations in the manufacture of felt hats fell ill.

In 140 AD e. The Chinese alchemist Vyi Poyang was engaged in the manufacture of “immortality pills.” Their composition is mercury sulfide. He took these pills himself, gave them to his students and to his beloved dog.

They all died, of course.

With an increase in the acidity of lake water by 1 pH unit, the concentration of mercury in fish tissues increases by an average of 0.14 mg/kg. In Sweden and the United States, anglers are advised to return caught fish to the lake if it is more than three years old.

One of the widespread sources of mercury is the well-known fluorescent lamps. One such fluorescent lamp contains -150 mg of mercury and, if thrown into a landfill and lost its seal, can pollute 500 thousand m of air with mercury at the MPC level. The Moscow ZIL plant alone annually sent 200 thousand waste mercury lamps to landfills.

2. 6. Arsenic and human health

Most arsenic is found in brain tissue, muscles and organs with developed muscle tissue.

From history

Since ancient times, this element has attracted human attention. They spoke about him with fear, admiration and contempt. For most people, the word “arsenic” has long become synonymous with the word “poison.” Scientists are still puzzling over the resolution of the issue: arsenic and the death of Napoleon 1 (1769-1821). Scottish doctors Smith and Forshufwood analyzed Napoleon's hair, cut from his head, a few hours after his death. (Even then, doctors knew that arsenic, once in the human body, gradually accumulates in the hair in the form of oxide). Analysis showed that the arsenic in Napoleon's hair was 13 times higher than normal. Doctors concluded that he was poisoned by arsenic, which, in their opinion, was mixed into his food in small doses in the form of oxide.

In that era, only arsenic could be poison. 1/5 g of arsenic is enough to kill a person in 24 hours, but arsenic retains its properties even when administered in small doses, and the killing lasts for months. This substance is grey, odorless and tasteless, and the symptoms of poisoning resemble those of cholera, which was then widespread in Europe.

It was almost impossible to diagnose poisoning during Napoleon's time, as it would be for a long time later. And if the person who was decided to be poisoned was forced to simultaneously take medications such as calomel (mercuric chloride) or certain potassium and antimony salts, then at autopsy it was completely impossible to detect traces of arsenic. (And these medications were often prescribed by doctors during the Napoleonic era, which made it possible to treat and at the same time kill the victim without leaving traces, committing in a certain sense the ideal crime.) Since the emperor had been taking calomel and potassium and antimony salts for the last days, by the time of the autopsy the slightest trace arsenic should have disappeared.

It also turned out that the wallpaper in the apartments of the former emperor also contained arsenic. Every square meter The wallpaper on the walls of Napoleon's bedroom contained 0.12 g of arsenic. When such wallpaper became damp, toxic arsenic compounds could be released into the air.

Alternating drowsiness and insomnia, swelling of the legs, hair loss * - all these are symptoms of chronic arsenic poisoning. The enlargement of the deceased's liver, which had no obvious signs of damage, exactly corresponds to the condition of the liver in such poisoning.

Until his death, Napoleon gained weight, while cancer patients (the official version of his death is stomach cancer) dramatically lose weight during their illness. Obesity is one of the symptoms of gradual arsenic poisoning.

In 1840, Napoleon's grave was opened. Napoleon's body was not embalmed and interred as it was after the autopsy. It was sealed in four coffins, including two metal ones, but none of them were airtight. 19 years have passed since the burial, but Napoleon’s body was not touched by decay. His face changed less than the faces of the people standing around his grave. There is an explanation for this miracle - arsenic; it is a deadly poison, but at the same time it protects living creatures from decomposition. Museums use this property of arsenic to preserve exhibits.

And despite the above, arsenic compounds are the most valuable medicines, the healing properties of which were known to Hippocrates and Aristotle. And although the role of arsenic compounds has significantly decreased with the discovery of antibiotics, some of its preparations are still used. The mystical aura surrounding arsenic and its diversity have a real basis: according to its position in the periodic system, it exhibits properties characteristic of both metals and non-metals, and hence the diversity of properties.

Biological role of arsenic

Arsenic is involved in processes associated with mechanical work and thinking, reduces the toxicity of selenium (the best remedy against selenium toxicosis), mercury and lead when they are in excess in the body. Takes part in nucleic acid metabolism, i.e. it is directly related to protein synthesis. Arsenic is necessary for the synthesis of hemoglobin, although it is not part of it.

Sources of arsenic entry into the human body

There are no arsenic-free diets. Marine organisms are rich in arsenic: sea fish (the arsenic content in them is 10-100 times higher than in freshwater) and marine crustaceans - shrimp, lobsters (their arsenic content reaches 174 mg/kg). There is even a term “shrimp arsenic”. Arsenic found in marine animals, despite its large amount, is non-toxic to humans. Its excess is excreted from the body.

Arsenic can enter the body when using arsenic-containing mineral waters. They are used both internally and in the form of baths at balneological resorts. They are used for the prevention and treatment of the cardiovascular, nervous systems, gastrointestinal tract, and musculoskeletal system strictly under the supervision of a physician. It was discovered that during the storage of Narzan mineral water, some black flakes appear in it. Chemists E.V. Iosifova and F.I. Golovin, having analyzed Narzan, found that it contained arsenic in quite large quantities. While there is a lot of carbon dioxide in the water, the salts are suspended in it, but as the gas evaporates and the pressure drops, they precipitate. Drinking water containing arsenic in an amount of 0.7 mg/l and above has a special therapeutic effect. In medicinal table waters, arsenic contains no more than 1.5 mg/l - these are the waters of Avadhara, Vardzia, Jermuk, etc. In medicinal waters, which are used strictly as prescribed by a doctor, arsenic can be several times higher . Among these, Sinegorskaya water (Sakhalin Island) distinguished itself; it contains arsenic up to 50 mg/l.

G. Flaubert’s novel “Madame Bovary” describes in detail the poisoning of the main character Emma with arsenic acid.

Did you know that.

A stone called a bezoar often forms in the gastrointestinal tract of animals. It has been used for centuries as a remedy for various poisons, especially arsenic, which poisoned many people in the Middle Ages. The stone was worn in a ring or medallion and taken orally with water. Queen Elizabeth 1 of England had such a stone. Modern American research has shown that a bezoar really effectively neutralizes arsenic compounds.

Chapter 3. Study of the content of certain elements in the human body

In order to answer the fundamental question of our work, we conducted a study of the content of iron, calcium and potassium among students of different age groups and teachers of Municipal Educational Institution Secondary School No. 11 using the methodology of M. Ham and A. Rossmeier. (Appendices 7,8,9). This technique is quite simple, its meaning boils down to the fact that by answering the questions of the questionnaire “yes” or “no”, you can get an idea of ​​​​the sufficient (insufficient) content of a particular element in the body.

Based on the survey of the above groups of respondents, we obtained the following results.

Age Quantity Potassium content Calcium content Iron content group of respondents

Yes No Yes No Yes No

13-14 years old 30 2 28 10 20 15 15

15-16 years old 25 1 24 11 14 10 15

25-35 years old 10 0 10 6 4 3 7

35-45 years old 15 6 9 4 11 5 10

Over 45 years old20 10 10 15 5 8 12

Analysis of survey results.

High school students (13-16 years old), answering the questionnaire, note a feeling of fatigue and depression (25 out of 55 respondents), changes in the skin and nails (20 out of 55 respondents), and consumption of a small amount of vegetables in the diet (60% of respondents) , drinking more than 3 cups of tea or coffee per day (48% of answers “yes”). In general, data have been obtained that 50% of high school students, answering “yes” to most questions on the questionnaire, have insufficient iron content in their bodies (according to the authors of the method for determining iron content, if the answers to most questions are “no”, then the body has sufficient degree provided with iron);

Analysis of teachers' answers allows us to see the following information picture: adults under 35 years of age have sufficient iron content (70% of answers “no”); age groups 35-45 years and over 45 years old have 50% and 67% “yes” answers, respectively, which indicates an insufficient supply of iron to the body.

2. Analyzing the information received on the body’s calcium supply in different age groups of respondents, the presence of “yes” answers is noted (the authors of the survey methodology claim that if the answer is “no” to most questions, then the body is sufficiently provided with calcium):

High school students (13-16 years old) – 62%;

Teachers under 35 years old – 60%, 35-45 years old – 27%, over 45 years old – 75%.

Moreover, survey participants noted frequent occurrence of cramps, consumption (and more often not) of less than one glass of milk per day, rare presence of foods such as yogurt and cheese in their diet, and, conversely, an abundance of meat and sausages.

Senior schoolchildren (13-16 years old) answered “no” to most of the questions in the questionnaire (the authors of the methodology claim that if the answer to most questions is “yes”, then the body does not have enough potassium) – 93%, which indicates sufficient potassium content;

Teachers under 35 years old answered “no” to all questions - 100%, 35-45 years old – 60% negative answers, over 45 years old – 50% “no” answers, that is, the majority of teachers have everything in order with the potassium content in the body.

Survey participants were familiarized with the results and analysis, and were also informed about the biological role played by potassium, calcium and iron in the body.

The results of the survey indicate that a number of survey participants did not have entirely favorable levels of the above-mentioned elements in the body, which can be explained by a number of objective and subjective factors:

1. Ecology of the place of residence, since the human body is a complex chemical system that cannot function independently, without interaction with the environment.

2. Social status, since incomes vary greatly among different social groups of the population, hence it is not always possible to purchase certain food products, which leads to a decrease in the content of certain chemical elements in the body.

3. Physiological characteristics of certain age groups associated with hormonal changes in the body.

4. Having bad habits and not understanding the importance of a healthy lifestyle.

Conclusion

The main feature of microelements is their ubiquity. Being unusually dispersed and scattered, they are present literally everywhere, although sometimes in vanishingly small quantities. Man today, like all living things, needs a certain content of microelements in his body, but, nevertheless, realizing this, human production activity on nature has led to a change in the chemical composition of the surrounding world: the concentration of microelements in the air, natural waters, and soil cover is changing , organisms, which does not pass without a trace for the organic world, including humans.

During the work on the abstract, the chemical composition of the human body, the physiological effects of alkali metals, calcium, halogens, iron, mercury and arsenic on the body were studied.

As a result, we can say that all the microelements considered have a beneficial function in the human body and any other living creature. But an excess or deficiency of these microelements in the body leads to adverse consequences, and in some cases to death.

In this regard, the statement of the ancient Greek philosopher and physician T. Paracelsus is relevant and appropriate: “Everything is poison and nothing is devoid of poisonousness, the dose alone makes the poison invisible.”

Maybe the time has come when every person should think about their health: how to maintain and strengthen their health and not harm themselves. The information material presented in our work allows us to form knowledge about preserving and strengthening our health, since from it we learn how substances affect the vital processes of the body, and in general, human life itself, what is useful for us and in what quantities, what is harmful and To what extent.

“Everything is chemistry” is an expression that can most often be heard from chemistry teachers at school, however, it is correct. Because, ultimately, absolutely everything consists of chemical elements. Our body too.

1. Oxygen. Not only is it an essential part of the air and drinking water we breathe, it also occupies a significant place in our body. With 65% of our total body weight, oxygen is the most important chemical element in the composition of the human body.

2. Carbon boasts not only the largest number of chemical compounds in the periodic table (the most famous of them are coal and oil). He also takes an honorable second place on our list.

3. Hydrogen, like oxygen, is a component of air and drinking water. And it also refers to the basic components of the human body. 10% of our weight is made up of hydrogen.

4. Although nitrogen is also found in the air, it is better known as a coolant in liquid form. However, its mysteriously evaporating gases should not be misleading - 3% of our body mass consists of nitrogen.

5. Even if it is only 1.5%, calcium is an important metal in our body. It is what gives strength to our bones and teeth.

6. Phosphorus, as a luminous substance, is known to everyone. But not everyone knows that it is thanks to phosphorus in the body that DNA, the basis of human life, is formed.

7. Potassium, with a modest 0.2%, takes little part in body processes. It belongs to the electrolytes that our body needs primarily during sports. Its deficiency can cause feelings of exhaustion and cramps.

8. Could sulfur, with its unpleasant appearance and smell, be important for our body? Yes, that's exactly it. Sulfur is an essential component of amino acids and coenzymes.

9. First sulfur, now chlorine. You might think that our body consists of only poisons. Of course, there is no elemental chlorine in our body, but there is chloride. And it is vitally important for us, since it is contained, for example, in blood plasma.

10. We consume sodium primarily in the form of sodium chloride, also known as table salt. The element is important for the protection of cells and the movement of nerve signals.

11. Magnesium is vital for all organisms on earth, naturally, for us people too. Despite its insignificant part - 0.05% of our body weight, a lack of magnesium leads to clearly noticeable consequences: Nervousness, headaches, fatigue and muscle cramps are just some of them.

12. The male body contains more iron than the female body. One of the reasons for this is the difference in nutrition. Another is that women lose iron during menstruation. Therefore, the average mass of this element in the human body varies from 2 to 5 grams.

13. Cobalt is a component of vitamin B12, which is essential for human existence. An overdose of cobalt leads to numerous diseases, including cancer.

14. Copper is lethal for microorganisms even in small quantities, but humans need it for the formation of vital enzymes. Heavy metal makes up 0.05% of our body weight. We get it through vegetables, chocolate and nuts.

15. Zinc is one of the elements that is needed by all living beings on earth. It is important for metabolism and is found in many important enzymes.

16. Iodine is a component of the hormones thyroxine and triiodothyronine, which are produced by the thyroid gland. Lack of iodine can cause severe metabolic disorders.

17. Selenium is an essential micronutrient. At the same time, in case of an overdose, it is highly toxic, so its use as a dietary supplement causes great debate in scientific circles.

18. To this day, it has not been fully clarified how necessary fluoride is for our body. An indisputable fact is that most fluoride is found in bones and teeth. Fluoride, like selenium, is highly toxic in overdose