State autonomous institution

Kaliningrad region

Professional educational organization

"College of Service and Tourism"

COURSE WORK

According to MDK 0n.0n.____________________ __

On this topic ________________________

Is done by a student _________________

(Full Name)

Group ______________________

(group number)

Training program for mid-level specialists in the specialty _

(code and name of the specialty)

Course leader:

(position, full name)

Mark ___________________________

Kaliningrad 2015

INTRODUCTION……………………………………………………………………….…2

1. Interaction of the human body with the environment………………....3

1.1. The main functional systems of man. Relationship between the life of the human body and the environment. The influence of the environment on human performance……………………………………………………………………………………………………………………………………………………………………………………………………………

1.2. The main parameters that determine the working environment (working conditions) in enclosed spaces, and their impact on the human body……….5

1.3. The influence of the working environment on the intensity of labor and the use of working time………………………………………………………...7

1.4. Suggestions for improving the environment at work ....... 9

2. Combustion and fire hazard of substances and industries……………………....11

2.1. Basic concepts. Physical and chemical bases of combustion………….........11

2.2. Properties of substances characterizing their fire hazard………….13

2.3. General fire safety requirements for production facilities………………………………………………………………………………………..16

2.4. The procedure for analyzing the fire hazard of a production facility and calculating the fire risk……………………………………………………………………..17

2.5. Classification of the main measures of fire prevention. Fire extinguishing media ……………………………………………………………………………...23

INTRODUCTION

A person is in constant relationship with the environment, which determines his behavior in a given situation. Moreover, not only the environment affects a person, but the individual himself influences it, changing and thereby adjusting it for himself.

Life safety is aimed at ensuring favorable conditions for the life of people, their activities, protecting a person and his environment from the influence of external, internal and dangerous factors.

Intensive use of natural resources, the introduction of scientific and technological progress is accompanied by the spread of various natural, biological, man-made, environmental and other hazards. Potential danger is a universal property in the process of human interaction with the environment.

In order for a person to feel comfortable, such conditions are necessary for his life activity in which he would feel safe. This can be achieved by establishing an inextricable relationship between man and his environment.

The purpose of the work is to consider questions:

Interaction of the human body with the environment;

Combustion and fire safety of substances and industries;

Ventilation, its purpose. The rate of air exchange. Method of calculation.

The interaction of the human body with the environment

1.1. The main functional systems of man. Relationship between the life of the human body and the environment. The influence of the environment on human performance. The human environment is a set of objects, phenomena and factors of the environment (natural and artificial) that determines the conditions of his life. One of the goals facing this system is security, i.e. no harm to human health. Achieving the safety of the "human-environment" system is possible only if the features of each element included in this system are systematically taken into account.

Characteristic systems "man-environment": domestic, industrial, urban, natural environment.

The natural environment is the factors of purely natural, or natural-anthropogenic systemic origin. The natural environment is a complex and diverse combination and interaction of the lithosphere, atmosphere, hydrosphere and the biosphere as a whole.

With the advent of industry and transport, the problem of maintaining the purity of the atmosphere, the pollution of which is of natural and artificial origin, has arisen. The main and most dangerous sources of air pollution are industrial, transport and household emissions. In the atmospheric air, and primarily in the air of industrial centers and cities, as a result of complex chemical reactions of a mixture of gases occurring in its lower layers, various substances are formed that accumulate in a poisonous fog - "smog". This phenomenon is associated with the deterioration of people's well-being, the emergence of influenza epidemics, a sharp increase in the number of pulmonary and cardiovascular diseases.

In addition, the ozone layer, which is a protective screen against ultraviolet radiation, is being destroyed in the atmosphere. This is due to the penetration into the layers of the atmosphere of the so-called freons used in the form of aerosols, solvents, etc. both at home and at work. In addition, there is a global increase in temperature on the planet, due to the "greenhouse effect", because. the content of carbon dioxide and methane in the atmosphere is growing rapidly.

All these and other changes occur through the fault of man, in the course of his industrial and other activities. Currently, a number of countries are trying to deal with this problem.

Another important component of the natural environment is the hydrosphere. Humanity is not threatened by lack of water. He is threatened by a lack of clean water. The main sources of pollution are industrial and municipal sewage, washing away from the fields of part of the soil containing various agrochemicals, etc.

All objects of the living world can be divided into plants and animals. The role of vegetation in people's lives is great (the forest releases oxygen and absorbs carbon dioxide, a person eats plants, etc.). But there are many threats to this component (fires, industrial waste pollution, etc.). The animal world is an important part of the biosphere of our planet, but the number of the animal world is currently declining, which cannot but affect the existence of mankind.

Most of the active life of a person is occupied by purposeful professional work carried out in a working environment, which, if the accepted regulatory requirements are not observed, can adversely affect his performance and health.

Efficiency is the value of the functional capabilities of the human body, characterized by the quantity and quality of work performed in a certain time. During labor activity, the performance of the body changes over time.

The production environment is a part of the human environment, including natural and climatic factors associated with professional activities (noise, vibration, dust, etc.), called harmful and dangerous. The impact of negative factors of the working environment leads to injuries and occupational diseases of workers. The most traumatic professions in the national economy include (%): driver (18.9), tractor driver (9.8), mechanic (6.4), electrician (6.3), gas fitter (6.3), gas electric welder (3 .9), handyman (3.5).

Human labor activity and the production environment are constantly changing in the process of intensive use of the products of scientific and technological progress and the implementation of broad socio-economic transformations.

The intensive growth of cities in the 20th century, the concentration of the bulk of the population in territories saturated with industrial enterprises, highways, residential buildings, gave rise to a number of problems, including the general problem of human security. In cities, especially in large ones, a number of environmentally hazardous industrial production, energy facilities are concentrated, an integral part of which are: powerful emissions of waste into the environment; thermal, electromagnetic, noise pollution; potential danger of large-scale industrial accidents, etc.

Currently, road transport has become the most dangerous for humans. Its victims are not only drivers and passengers, but also pedestrians. Other modes of transport are also dangerous. In the list of emergencies, fires occupy a leading position in terms of the frequency of occurrence and the amount of material damage caused. At the same time, methods of combating and protecting against them are developed carefully and systematically. In Russia, modern methods of ensuring life safety are reflected in legislative acts in all spheres of human activity.

Based on the foregoing, we can conclude that basically a person creates a threat to life and activity for himself.

1.2. The main parameters that determine the working environment (working conditions) in enclosed spaces, and their impact on the human body

Any type of labor activity is a complex set of physiological processes that involve all organs and systems of the human body. In order for a person to feel comfortable during the production process, which means that his working capacity is increased, it is necessary that his working conditions meet the basic standards and requirements. General safety requirements for production equipment and production processes are established by GOST 12.2.003-91 and GOST 12.3.002-75. The safety of production processes is mainly determined by the safety of production equipment.

Most often, a person works indoors, while his working conditions must meet certain parameters. including harmful factors. It is very important to maintain the thermal balance of the body. The industrial microclimate depends on the climatic zone and the season of the year, the nature of the technological process, the type of equipment used, the size of the premises and the number of workers, the conditions of heating and ventilation.

Normative indicators of the industrial microclimate are established by GOST 12.1.005-88 and SanPiN 2.2.4.584-96.

Optimum and acceptable microclimatic conditions must be created in the working area of ​​industrial premises. This is achieved by means of industrial ventilation (natural and artificial).

Lighting is a factor affecting the human body, and, accordingly, the quality of the production task. With proper lighting of the working area and production facilities, the number of accidents is reduced, and labor productivity is increased. Deviations in lighting harm the health of workers, can cause diseases (for example, myopia), are fraught with a decrease in mental and physical performance, and an increase in the number of errors in production processes. Lighting can be natural or artificial. When organizing industrial lighting, it is necessary to ensure a uniform distribution of brightness on the working surface and surrounding objects. The environment of the production organism.

Chemicals, synthetic materials that are irrationally used in production conditions are of great danger. Vapors, gases, liquids, aerosols, compounds in contact with the human body can cause diseases or deviations in health. Exposure to harmful substances on a person can be accompanied by poisoning and injury. In production, toxic substances enter the human body through the respiratory tract, gastrointestinal tract and skin. The maximum permissible concentrations of harmful substances in the air of the working area are regulated by GOST 12.1.005-88 and GN 2.2.5.686.

Another important hazard factor is mechanical vibrations: vibration, noise, infrasound, ultrasound. All these physical processes are associated with the transfer of energy, which, with a certain amount and frequency, can have an adverse effect on a person: cause various diseases, create additional dangers. There are several types of vibration, depending on each of them and the consequences of this factor are different. Under the action of general vibration on the body, the musculoskeletal system, the nervous system, and such analyzers as vestibular, visual, and tactile suffer. Local vibration causes spasms of the vessels of the hand, forearms, associated with impaired blood supply to the extremities. At the same time, vibrations act on nerve endings, muscle and bone tissues. Noise, infrasound and ultrasound are classified as acoustic vibrations, which can be both audible and inaudible. Intensive noise in the workplace leads to a decrease in attention and an increase in the number of errors in the performance of work. Noise reduces productivity and quality of work. The entire human body is exposed to noise: it depresses the central nervous system, causes a change in the rate of breathing and heart rate, contributes to metabolic disorders, the occurrence of cardiovascular diseases, stomach ulcers, etc. Infrasound is referred to as vibrations inaudible to humans. In production conditions, infrasound, as a rule, is combined with low-frequency noise, in some cases, with low-frequency vibration. When the body is exposed to infrasound with a level of 110 to 150 dB, unpleasant subjective sensations and functional changes may occur: disturbances in the cardiovascular and respiratory systems, the central nervous system, and the vestibular analyzer.

1.3. Influence of the working environment on the intensity of labor and the use of working time

Human labor activity and the environment are constantly changing in the process of accelerating scientific and technological progress and the implementation of broad socio-economic transformations. At the same time, labor remains the first, basic and indispensable condition for human existence. Diverse forms of labor activity are divided into physical and mental labor.

Physical labor is characterized primarily by an increased load on the musculoskeletal system and its functional systems (cardiovascular, neuromuscular, respiratory, etc.), which ensure its activity.

Mental work combines work related to the reception and processing of information that requires the primary tension of the sensory apparatus, attention, memory, as well as the activation of thought processes, the emotional environment.

Currently, there are several basic forms of labor that require a certain intensity of labor and the use of working time.

1. Forms of labor that require significant muscle energy.

Intense physical labor, which stimulates the development of the muscular system and metabolic processes, has at the same time a number of disadvantages. The main one is inefficiency associated with low labor productivity and the need for breaks to restore physical strength, which make up up to 50% of working time.

2. Mechanized forms of labor.

The mechanization of labor makes it possible to reduce the nature of muscular loads and complicate action programs. However, the monotony of simple actions and the small amount of information perceived at the same time lead to the monotony of work.

3.Forms related to automated production.

With automated forms of labor, the employee is required to be constantly ready for action and the speed of reaction necessary for the timely elimination of problems that have arisen.

4. Group forms of labor - conveyor, a distinctive feature of which is the division of the general process into specific operations, a strict sequence of their implementation, automatic supply of parts to each workplace using a conveyor belt.

One of the negative consequences of assembly line work is monotony, which is expressed in premature fatigue and nervous exhaustion.

5. Forms of labor associated with the management of production processes and mechanisms (mental labor).

Intellectual work consists in the processing and analysis of a large amount of various information, and therefore requires the mobilization of memory, attention, tension of the sensory apparatus, and the activation of thinking processes. Muscle loads are insignificant.

Intellectual labor is characterized by hypokinesia, i.e. a significant decrease in human motor activity, leading to a weakening of the body's reactivity and an increase in emotional stress.

1.4.Suggestions for improving the environment at work

To increase the working capacity of a person, it is necessary to create comfortable conditions for him in the workplace, no matter what work he does. For example, to protect a person from receiving mechanical injuries, it is necessary either to prevent him from entering dangerous zones, or to build special devices that protect a person from a dangerous factor.

It is very important to install information, warning, emergency devices for automatic control and signaling to ensure the safe and reliable operation of the equipment.

It is very important to properly organize the workplace for those who work on personal computers. To do this, it is necessary that the room is spacious enough, well ventilated, properly lit. You can not work on a computer in a dark and semi-dark room.

In addition, a person, working at a computer, moves very little, which negatively affects his health. In such organizations, it is possible to organize, for example, a “day of sports” twice a month (going to the gym, swimming pool, etc.). In my opinion, this will unload the employee emotionally and maintain physical fitness, which will only positively affect his performance and efficiency in completing tasks.

In production, to protect workers from harmful emissions and emissions, it is necessary to install various filters to reduce their concentrations in the ambient air. To protect against harmful discharges of the hydrosphere, such methods are used as the rational placement of sources of discharges, and the organization of water intake and drainage; dilution of harmful substances in water bodies to acceptable concentrations, and also use wastewater treatment products (mechanical, physico-chemical, biological methods).

It is very important to learn how to protect the environment from waste received from industrial and other industries. To do this, it is necessary to introduce technologies for the collection and disposal of waste. Including waste recycling, which will ensure minimal environmental pollution. The most effective solution to the problems of protection against industrial waste is possible with the widespread introduction of low-waste technologies.

The organism is a biological system of the biosphere

Every living being is organism, which differs from inanimate nature by a set of certain properties inherent only in living matter - cellular organization and metabolism.

From the modern standpoint, the organism is a self-organizing energy-information system that overcomes entropy (see Section 9.2) by maintaining a state of unstable equilibrium.

The study of the relationship and interaction in the "organism-environment" system led to the understanding that the living organisms that inhabit our planet do not exist by themselves. They are completely dependent on the environment and constantly experience its effects. Each organism successfully survives and reproduces in a specific habitat characterized by a relatively narrow range of temperatures, rainfall, soil conditions, and so on.

Consequently, the part of nature that surrounds living organisms and has a direct or indirect effect on them is their habitat. From it, organisms receive everything necessary for life and excrete metabolic products into it. The habitat of each organism is composed of many elements of inorganic and organic nature and elements introduced by man and his production activities. At the same time, some elements may be partially or completely indifferent to the body, others are necessary, and still others have a negative effect.

living conditions, or conditions of existence, is a set of elements of the environment necessary for the organism, with which it is in inseparable unity and without which it cannot exist.

Homeostasis - self-renewal and maintenance of the constancy of the internal environment of the body.

Living organisms are characterized by movement, reactivity, growth, development, reproduction and heredity, as well as adaptation. in metabolism, or metabolism, a number of chemical reactions take place in the body (for example, during respiration or photosynthesis).

Organisms such as bacteria are able to create organic compounds at the expense of inorganic components - compounds of nitrogen or sulfur. Such a process is called chemosynthesis.

Metabolism in the body occurs only with the participation of special macromolecular protein substances - enzymes acting as catalysts. In regulating the process of metabolism in the body, enzymes help vitamins and hormones. Together they carry out the overall chemical coordination of the metabolic process. Metabolic processes proceed along the entire path of the individual development of the organism - ontogenesis.

Ontogeny - a set of successive morphological, physiological and biochemical transformations undergone by the body over the entire period of life.

Habitat of an organism- a set of constantly changing conditions of his life. The terrestrial biota has mastered three main habitats: and soil, together with rocks of the near-surface part of the lithosphere.

Living organic matter on Earth, being an extremely active focus of specific energy, is distinguished at the same time by an exceptional variety of forms of its manifestation.

The diversity of these forms is the result of the long development of the organic world and its adaptation to a geographic environment that is variable in time and space.

The organism is inextricably linked with the environment and is inconceivable outside this environment, if only because one of the main manifestations of life (however, not exhaustive of the qualitative specifics of life processes) is metabolism. Other signs of living things: sensitivity, mobility, growth, development, reproduction, heredity, variability. The existence of any organism is composed of the acceptance and accumulation of matter (assimilation) and the excretion and expenditure of matter (dissimilation). The environment is the only source of substances from which the body builds its body. Outside of metabolism, no substance can be formed in the body. The interaction of living bodies with the environment is an indispensable condition for their preservation and existence, in contrast to inanimate bodies, for which interaction with the environment is a condition for their destruction.

Assimilation is the ability of the living to perceive, modify and liken itself to the substances of the external environment. Animals assimilate mainly substances of an organic nature, plants - inorganic. But in both cases, in the process of assimilation, the inanimate turns into the living, the external into the internal. The body is constantly building itself from the substances of the external environment in its own way.

Dissimilation (decay) represents the other side of a single contradictory process of metabolism. It serves as a source of energy, due to which biochemical reactions of synthesis (assimilation) and all other manifestations of vital activity (movement, etc.) take place, and two types of energy sources predominate: biological oxidation reactions that underlie respiration, and non-oxidizing decomposition of mainly carbohydrates , i.e. fermentation-type reactions. An important feature of living matter is that all biochemical reactions in the metabolism do not proceed in a random, but in a strictly defined sequence, that is, they are ordered in time, linked into an integral system. This ensures, in the presence of a ceasing decay, the constancy of the composition and structure of the organism.

Metabolism is the basis of all life processes. The connection of the organism with the environment presupposes the correspondence of the organism to the conditions of its existence, the adaptation (adaptation) of the organism to the environment. This is observed everywhere in nature, and adaptation covers all the properties and characteristics of organisms - their shape, color, physiological functions, behavior, etc. - and helps the body make the best use of the environment, get rid of danger, facilitate an attack on the victim, ensure only life, but also reproduction.

As a result of what and how did the adaptations of organisms to the environment develop? What is the driving cause of the formation and improvement of forms of animals and plants, i.e., the cause of the development of the organic world, the transition of simple forms into more complex ones?

Everyday observation and experience show that during reproduction, organisms reproduce from generation to generation only their own kind. This biological inertia, the property of offspring to retain the characteristics of their parents, is called heredity. Another property of an organism - its biological plasticity, the ability to change in comparison with its parents - is called variability.

Variability is the result of the influence of the external environment, as well as the result of the correlation between the organs and functions of the body, due to which a change in some entails a change in others. Heredity is defined as the property of a living body to require certain conditions for its life, its development, and to definitely respond to certain conditions. If an organism finds in its environment and assimilates something that fully meets its requirements, it retains its resemblance to its parents. Insignificant changes in the environment, contained within some relatively narrow limits, do not change the heredity of the organism, since they do not disturb the general nature of metabolism. However, any serious change in the conditions of life, caused by the vital activity of the organism itself or a change in the environment, inevitably entails a change in the type of metabolism. At the same time, since there is no life outside of metabolism, the organism must either die or adapt to new conditions, that is, change in accordance with these conditions, change its heredity.

By resorting to the alteration of organisms, man has long used both variability and heredity. The accumulation and creation by a person of certain traits chosen by him in some animal or plant by using variability and heredity is called artificial selection, selection, or selection. In selection, a very important role is played by a person's change in the living conditions of the organism, a change in the type of metabolism.

In the natural environment, of course, the same laws of variability and heredity operate, but here selection is no longer controlled by man, but by the struggle for existence, understood in a broad sense as the survival of the fittest. Unlike artificial selection in nature, called natural selection, works for the benefit of the organism itself (and not the person).

The inevitability of natural selection follows from the fact that more individuals of a given species are born in nature than the conditions available for their life allow. True, a huge number of embryos and individuals die regardless of the degree of their adaptation to the environment (eating of caviar by predatory fish, the death of seeds of terrestrial plants that have fallen into the water, floods, fires and other natural disasters). At the same time, a huge number of individuals who survived spontaneous death remain subject to many adverse conditions of inanimate nature, epidemics, attacks by enemies, are forced to fight for food, light, space, water (in particular, with representatives of their own species, which make similar demands on the environment). ), etc. Under these conditions, only those are destined to survive: organisms that have signs that give the organism in the created situation some advantage for its existence and further reproduction. As a result of variability, heredity and natural selection, varieties arise within a species. In the course of time, the characters of the extreme varieties diverge so much that new species are formed from these varieties, and the intermediate varieties, being less adapted, die out as a result of natural selection.

Thus, the development of the organic world has an adaptive character. The variety of forms of living beings is a variety of forms of adaptation, but adaptation is relative, temporary, having significance only in a certain life situation. The situation is changing - the former adaptability loses its meaning.

The organism in itself has no particular desire for expedient change. Expediency in the structure, functions and behavior of the organism is the historical result of long-term natural selection, and not at all the original property of living matter.

The adaptation of the organism to the environment is most clearly expressed within the area in which it usually lives. Transferred to another environment, the organism can adapt to it, but the degree and nature of this adaptation largely depend on the biological plasticity of the organism. Some organisms die in a new environment, others live and reproduce, others live but do not reproduce, which practically means that the species to which this individual belongs is condemned to death in a new environment, since the individual leaves no offspring. Some organisms live by keeping old habits, others change these habits. For example, the Australian black swan nests in its homeland in November-December, and in the zoos of southern Ukraine in March-April, that is, in both cases in the spring, but in different months of the year, in accordance with the course of climatic processes in the northern and southern hemispheres.

The doctrine of natural selection can only be applied in biology. It is not a universal methodology of science, it cannot be transferred to human society and the laws of development of this society.

INTERACTION OF A LIVING ORGANISM AND THE ENVIRONMENT

On Earth, organisms are very diverse. Among the plants you can also find microscopic algae, whose life is very short, small annual flowering plants, larger perennial flowering plants, giant ancient sequoias. The smallest crustaceans inhabiting the water column, jellyfish, starfish, molluscs, beetles, lizards, frogs, sparrows, hawks, wolves, deer, buffaloes, whales - this is not a complete list of various representatives of the animal world. Plants and animals are very closely interconnected and determine the optimal existence of each other. However, the living organisms that inhabit our planet are closely connected with their environment. The study of the system of these interrelations and dependencies is also the prerogative of bioecology.

Habitat An organism is a set of abiotic and biotic conditions of its life. The properties of the environment are very diverse and constantly changing. Therefore, living organisms are forced to adapt to these changing conditions in order to ensure their optimal existence. The process of adaptation of living organisms to environmental conditions is called adaptation.

There are four main habitats for living organisms:

• - water;
• - ground-air environment;
• - the soil;
• - the environment formed by the living organisms themselves.

Water -- the first habitat inhabited by living organisms. Many living organisms live in it, receiving all the substances necessary for life: food, water, oxygen. All living organisms inhabiting the aquatic environment are called "hydrobionts". No matter how highly organized these living organisms are, they are all forced to adapt to the characteristics of life in the aquatic environment. These features are determined by the physical and chemical properties of water.

IT IS INTERESTING! In the water column there is constantly a large number of the smallest representatives of plants and animals leading life in suspension. Their ability to soar is provided not only by the physical properties of water, which has a buoyant force, but also by special adaptations of the organisms themselves. For example, numerous outgrowths and appendages that significantly increase the surface of the body relative to its mass and, consequently, increase friction against the surrounding fluid. Another example is jellyfish. Their ability to stay in the water column is determined not only by the characteristic shape of the body, reminiscent of a parachute. The body of a jellyfish is 98% water, so the density of the body of a jellyfish is very close to the density of water.

Animals have adapted to moving in water in different ways. Active swimmers (fish, dolphins, etc.) have a characteristic streamlined body shape and fin-like limbs. Their fast swimming is also facilitated by the features of the outer cover of their body and the presence of a special lubricant - mucus, which reduces the friction of the body against water.

In some water beetles, the exhaust air released from the spiracles is retained between the body and the elytra due to the presence of hairs that are not wetted by water. With the help of such a device, an aquatic insect quickly rises to the surface of the water, where it releases air into the atmosphere.

Water has the property of accumulating and retaining heat (heat capacity). For this reason, there are no sharp temperature fluctuations in water, which are typical for land.

One of the most important properties of water is the ability to dissolve other substances that can be used by aquatic organisms for respiration and nutrition. First of all, aquatic organisms need oxygen.

IT IS INTERESTING! Respiration of aquatic organisms can be carried out both by the entire surface of the body, and by special organs - gills. For proper breathing, it is necessary that near the body of the animal there is a constant renewal of water, which is achieved by various movements of the animal itself. The suspended state of small particles and their transport by moving water determine the feeding habits of many animals, whose eating organs are arranged according to the principle of a sieve. In order to filter out a sufficient amount of food particles, a very large amount of water has to be passed through this sieve. For many aquatic organisms, a constant supply of a new portion of water is necessary, from which they will receive the next portion of food. This can be provided by the movement of the animal itself or by special devices, such as oscillating cilia or tentacles, which produce a whirlpool near the animal's mouth, driving food particles into it.

Salt composition of water is very important for life. Of particular importance for many organisms is the presence of calcium ions in the water, which is required by crustaceans and molluscs to build a shell.

ground-air environment, mastered in the course of evolution later than water, is more complex and diverse in terms of habitat conditions, which leads to a higher level of morphophysiological organization of living organisms inhabiting it.

The most important factor in the life of organisms living here is the properties and composition of the surrounding air masses. The density of air is much lower than the density of water, therefore, in terrestrial organisms, supporting tissues are highly developed - the internal and external skeleton.

Air masses are also characterized by a huge volume and are constantly in motion, the air temperature can change very quickly and over large spaces. Therefore, organisms living on land have numerous adaptations to withstand sharp temperature fluctuations or avoid them altogether. A remarkable adaptation is the development of warm-bloodedness.

IT IS INTERESTING! In general, the ground-air environment is more diverse than the water; living conditions here vary greatly in time and space. These changes are noticeable even at a distance of several tens of meters, for example: at the border of a forest and a field, at different heights in the mountains, even on different slopes of small hills. At the same time, pressure drops are less pronounced here, but often there is a lack of moisture. Therefore, terrestrial inhabitants have developed adaptations associated with providing the body with water, especially in arid conditions. In plants, this is a powerful root system, a waterproof layer on the surface of leaves and stems, and the ability to regulate the evaporation of water through stomata. In animals, in addition to the structural features of the external integument, these are behavioral features that contribute to maintaining the water balance, for example, migration to watering places.

Of great importance for the life of terrestrial organisms is the composition of the air (79% nitrogen, 21% oxygen and 0.03% carbon dioxide), which provides the chemical basis of life. Carbon dioxide is the most important raw material source for photosynthesis. Air nitrogen is necessary for the synthesis of proteins and nucleic acids.

The soil as a habitat - the upper layer of land, formed by mineral particles processed as a result of the vigorous activity of living organisms that live in the soil. Soil is an important and very complex component of the biosphere, closely related to its other parts. The soil as a habitat is unusually adapted for the life of many living organisms. This is due to the specific features that it possesses. Temperature fluctuations are smoothed out in the soil, it is rich in nutrients. Between soil particles there are numerous cavities that can be filled with water or air. Therefore, the soil is inhabited by both aquatic and air-breathing organisms. Another feature of the soil is that even at a shallow depth it is completely dark. In addition, as it sinks into the soil, its oxygen content decreases, and carbon dioxide increases. Therefore, only anaerobic bacteria can live at a considerable depth, while in the upper layers of the soil, in addition to bacteria, fungi, protozoa, worms, arthropods, and even large animals that make passages and build shelters and dwellings in the soil are found in abundance.

The impact of the environment is perceived by organisms through environmental factors, which are called environmental.

Environmental factors -- These are certain conditions and elements of the environment that have a specific effect on living organisms. Conventionally, all environmental factors are usually divided into three large groups: abiotic, biotic and anthropogenic.

Biotic factors- these are all kinds of forms of influence of living organisms on each other (for example, pollination by insects of plants, eating by some living organisms of others, and much more). Biotic relationships are extremely complex and idiosyncratic and can also be direct or indirect.

In modern conditions, the effect of environmental factors is often determined not by the natural environment, but by the changes that have been made to it by man. Therefore, it is customary to single out another type of factors - anthropogenic.

Anthropogenic factors -- these are those forms of human activity that affect the environment, change the living conditions of living organisms, or directly affect individual species of plants and animals. Human activities can have both direct and indirect effects on nature. The direct impact includes the extermination, reproduction and settlement by humans of both individual species of animals and plants, and entire communities. Indirect impact occurs as a result of changes in the habitat of organisms: climate, river flow regime, plowing of the surface layer of land, etc.

One of the most important anthropogenic factors is environmental pollution. At present, the influence of man on nature has largely lost its local character and has a global distribution. Increasingly, this influence negatively affects the development of flora and fauna, the purity of atmospheric air and the quality of natural waters, etc.

IT IS INTERESTING! Living organisms are not only influenced by their environment, but also actively influence their environment. As a result of their vital activity, the physical and chemical properties of the environment (the gas composition of air and water, the structure and properties of the soil, even the climate of the area) can change markedly.

The simplest influence of life on the environment is mechanical action. Building holes, laying passages, animals greatly change the properties of the soil. The soil changes, and under the influence of the roots of plants, it becomes stronger, becoming less susceptible to destruction by water currents or wind. The well-known construction activity of beavers causes serious changes in the water regime of the rivers on which they build their dams. As a result, this leads to a change in the flora and fauna of those basins where they live. At the same time, the ability of herbivorous fish (such as silver carp or grass carp) to clear watercourses from thickets of aquatic vegetation, which they actively feed on, is used by man in the fight against overgrowth of various water structures.

Small crustaceans living in the water column, insect larvae, molluscs, many fish have a peculiar type of food called filtration. Constantly passing water through the mouth apparatus, these animals continuously strain out food particles contained in solid suspensions from it. Such activity significantly affects the quality of natural masses: animals carry out their constant cleaning, like giant filters. environment organism biotic plant

The physicochemical impact of living organisms on the environment is also of great importance. The most important here are green plants, thanks to which the chemical composition of the atmosphere is formed as a result of the process of photosynthesis. Photosynthesis is the main supplier of oxygen to the atmosphere, thus providing life for a huge number of earthly inhabitants, including man himself.

By absorbing and evaporating water, plants also affect the water regime of their habitat. The presence of vegetation contributes to the constant humidification of the air. In addition, the vegetation cover softens daily temperature fluctuations near the earth's surface, as well as fluctuations in humidity and wind, and has a beneficial effect on the structure and chemical composition of soils. All this creates a certain microclimate that promotes the development of other organisms.

The formation of gases such as nitrogen, carbon dioxide, ammonia largely depends on the activities of the inhabitants of our planet. Living matter also changes the physical properties of the environment: its thermal, electrical and mechanical properties.

No living organism can be imagined outside the environment and outside interaction with it. From the environment, the body receives nutrients and oxygen, and gives the end products of metabolism into it. The environment affects it with a number of its factors: radiant energy (light, ultraviolet, radioactive), electromagnetic fields, atmospheric and hydrostatic (for those leading an aquatic lifestyle) pressure, temperature, and various chemicals. It inevitably involves interaction with other living organisms.

The body continuously receives information from the environment, to which it reacts in the form of responses: movements, speech (in animals - the publication of certain sounds, facial expressions, eating food, etc. Thus, a living organism continuously passes through itself not only substances and energy, but also the flow of information.

Information is perceived by special receptor apparatus - the sense organs, then transmitted to the central nervous system, where the signal is "recognized" and a response is formed. Information passes through communication channels either in the form of electrical impulses along nerve fibers in one direction or another (nerve connection), or with the help of chemicals through the bloodstream (humoral connection). In this case, the nervous connection is clearly directed to a certain area (center) of the nervous system or organ, and the humoral connection is more generalized, that is, it is directed not at one target, but at several at once. The perceiving capability of different receptors and the throughput of communication channels are not the same, therefore the flow of information received by the receptor, transmitted from it to the center and stored in memory, is also different.

The amount of information is usually measured in binary characters - bits. In humans, the flow of information through the visual receptor is 10 8 -10 9 bit/s. The neural pathways pass 2 x 10 6 bps. About 50 bps reach consciousness, and only 1 bps is firmly retained in memory. Thus, for 80 years of life, the memory retains information of the order of 10 9 bits. Consequently, the brain evaluates not all, but the most important information. On the way to it, everything insignificant is eliminated, filtered out.

The information received from the environment determines the work of the functional systems of the body and the behavior of a person or animal, regulating them: strengthening or weakening.

To control a person's behavior and the activity of his functional systems (that is, the output information coming from the brain), about 10 7 bits / s is sufficient when connecting the programs contained in the memory.

The vital activity of the organism is regulated primarily at the subcellular and molecular levels. This is a chemical autoregulation of metabolic reactions. It solves local problems and is the basis of all types of regulation. It is carried out by changing the concentrations of metabolites, increasing or decreasing the activity and quantitative content of enzymes, i.e., enhancing or inhibiting their synthesis, structural changes in them and other functional proteins. But regulation also occurs at higher levels: the cell as a whole, tissue, organ, functional system, organism. The higher the control output signals are transmitted, the more generalized they are. In humans and animals, the highest center that controls autonomic functions (blood circulation, respiration, movement, hormone secretion, etc.) is the hypothalamus, located in the lower part of the diencephalon, which has connections with the system of endocrine glands, other parts of the brain and the center of consciousness - its bark. Incoming signals may or may not be conscious. Control responses to unconscious environmental signals can be carried out by the hypothalamus without the participation of the higher part of the brain - its cortex.

In normal, habitual environmental conditions for the body, it is in a state of equilibrium with it. It maintains the constancy of both the level of activity of functional systems and the composition of its internal environment. But environmental conditions can change in an unfavorable direction for the body. Often these changes occur very quickly, and sometimes carry disturbing information. But the body is not always able to immediately tune in so as to endure new conditions without significant harm. So, being at a height where the partial pressure of oxygen and carbon dioxide is reduced, under the influence of the information received, the body rearranges its functional activity to changed levels: the frequency and minute volume of breathing, the heart rate increase, the volume of circulating blood increases, but the degree of saturation of arterial blood with oxygen equally decreases.

The effect of low barometric pressure on some functions of the human body

Pressure, kPa	Height above sea level,	Partial pressure in alveolar air, kPa		Frequency in 1 min		Minute breathing volume, l/min	Volume of circulating blood, ml/kg	Saturation of arterial blood with oxygen,%
					heart rate

If a person first got into the mountains and is not prepared for such conditions, he may develop mountain sickness due to a lack of oxygen (hypoxia) and an increased return of carbon dioxide that excites the respiratory center (hypocapnia). First, general weakness and headache appear, the perception of taste and smells is disturbed (for example, it begins to seem that the sausage smells like fish, and the bread is bitter), the psyche is depressed, then auditory and visual hallucinations join, and the person loses consciousness. Breathing either stops, then (as carbon dioxide accumulates in the blood) resumes, then (due to the removal of CO 2 from the blood) stops again, etc. If a person is not given an oxygen apparatus or lowered to a lower level, he may die. So it was, for example, in the last century with the crew of the French balloon "Zenith", brought to a great height, as a result of which all three people who were in the gondola died. The ascent of climbers of a foreign team also ended tragically, who, being at an altitude of 6000 m without oxygen devices, found themselves due to an unexpected change in the weather under the conditions of a barometric minimum of a cyclone corresponding to an altitude of more than 10,000 m.

This means that the body must gradually adapt to staying at heights, to conditions of hypoxia, since the emergency adaptation of an organism that is not prepared for staying in hypoxic conditions is not complete and, with a large force of environmental influence, is insufficient. Nowadays, not a single climber will go on an ascent without preliminary mountain acclimatization.

Let us give an example of the action of high and low temperatures. Life processes are possible only within a strictly limited range of body temperature, for example, for monkeys it is from 13-14 to 43-45°C. Temperatures above and below these limits are incompatible with life. But even within the permissible range of body temperature in the body, a number of adverse changes are possible. The kinetic energy of atoms and molecules of the body depends on body temperature. If it is too high (at high temperatures) or too low (at low temperatures), it will adversely affect metabolism, the speed at which life processes proceed, and the cellular structures on which life depends. The fact is that all the enzymes of the body have a certain temperature optimum of action, at which they show the greatest activity. This optimum is close to body temperature. When the temperature deviates from the optimum (in both directions), the activity of enzymes decreases. With shifts in body temperature, the higher structures of proteins and RNA change. Thus, low temperatures lead to disruption of the tertiary and quaternary structures of many proteins. If it is a protein-enzyme, then its activity is reduced. High temperatures affect tRNAs in such a way that they lose their ability to attach and transport amino acids necessary for protein synthesis. Under the influence of temperature changes, the interaction of hormones with tissue receptor proteins is also disrupted, and, consequently, the hormonal regulation of body functions and its metabolism.

Naturally, all these changes lead to a violation of a number of body functions. In the process of metabolism in any organism, heat is generated. Its source is ATP (see Scheme 1), if it hydrolytically splits without transforming its chemical energy into the energy of any physiological work (movement, electrophysiological processes, osmotic work, etc.). But not all organisms can store this heat by maintaining a constant body temperature. This ability is possessed only by birds and mammals (both animals and, naturally, humans). They are called homoiothermic organisms. The body temperature of invertebrates, fish, amphibians and reptiles depends on the ambient temperature and is almost equal to it. These are poikilothermic organisms. Therefore, the thermal optimum, in which an individual leads an active life, is much wider in homoiotherms than in poikilotherms, although the limits of survival under conditions of a temperature maximum and minimum pessimum are almost the same (Fig. 3).

At low temperatures (but compatible with life), poikilothermic animals hibernate or are extremely inactive. For example, at an ambient temperature of 21 0 C, a tsetse fly actively flies, from 20 to 14 0 C it takes off only when it is disturbed by something, at 10 0 C it can only run, and at 8 0 C and below it is immobile. Unable to regulate their body temperature and maintain it at a constant level, poikilotherms actively try to avoid extreme temperatures when thermal conditions change. For example, fish living in the coastal zone of tropical seas, at low tide, when the water is very warm, go to deeper places where the water is cooler, and the fish of freezing rivers in winter also swim to the depths, where the water is warmer than where it comes into contact with ice. Amphibians and reptiles bask in the sun in cool times, and hide in the shade or take refuge in burrows in hot times. Finally, the fact that they are close to each other helps to maintain some body temperature in poikilotherms. In the summer, the bees in the hive are away from each other and at the same time ventilate the space with their wings, which contributes to better evaporation of moisture and cooling. In winter, they gather together, forming a dense mass, thereby limiting the return of their heat. According to Japanese researchers, the temperature in the hive is maintained at the level of 18-22 0 C at an external temperature of 11 to -7 °C. All this helps to evade the harmful action of the thermal factor, but does not make the animals less sensitive to it.

Homoiothermal organisms, which, along with powerful possibilities of heat production, also have a very perfect system of thermoregulation, are another matter. The formation of heat in them, as in all animals, occurs due to oxidative processes and the splitting of ATP, and its release occurs in three ways: convection, i.e., conduction from a warmer organism to a colder environment (30%), radiation (45 %) and evaporation of water, which contributes to cooling (25%). At the same time, 82% of heat is given off through the skin, 13% - through the respiratory organs, 1.3% - with urine and feces, 3.7% goes to warm the food eaten and the water drunk. With an increase in external temperature, heat production decreases, and heat transfer increases; when it decreases, heat production increases and heat transfer decreases. This is the main difference between homoiothermic and poikilothermic ones: with an increase in external temperature, the metabolic rate of the latter becomes greater, and when it decreases, it sharply decreases.

Maintaining a constant body temperature in homoiothermics is carried out both at the organ level and at the subcellular - molecular level. The regulation of heat transfer by conduction and radiation is based on changes in skin circulation. At high external temperatures, the vessels of the internal organs narrow, and the skin ones expand, which enhances heat transfer; at low temperatures - on the contrary, and the heat transfer is sharply reduced. The release of heat by evaporation is provided by sweating, since the evaporation of sweat cools the body. Evaporation of 1 g of sweat takes about 2.0 kJ of heat from the body. With an increase in external temperature, sweating increases sharply: up to 0.5 - 1.0 l / h, i.e., it reaches 24 l / day. In animals that do not have sweat glands (for example, in dogs), the place of evaporation of moisture is the mucous membrane of the tongue and oral cavity. Everyone knows that during the heat the dog opens its mouth, sticks out its tongue and breathes rapidly: instead of sweat evaporation, saliva evaporates.

All these heat transfer mechanisms are regulated by the central nervous system - a heat center located in the hypothalamus. If the brain is cut below the hypothalamus, then the homoiothermic animal becomes poikilothermic. The thermal center consists of two centers: heat production and heat transfer. Irritation of the first leads to an increase in temperature, an increase in gas exchange, narrowing of the skin vessels and chills, which increases heat generation in the muscles; irritation of the second - to shortness of breath, sweating, expansion of skin vessels and a drop in body temperature. The excitation of both centers occurs both reflexively: as a result of signals from skin receptors - thermosensitive nerve endings, and chemically: during the transport of hormones and some other chemicals by the blood.

However, despite all the mechanisms of thermoregulation inherent in homoiotherms, sudden and significant changes in the temperature of the environment can be disastrous for the body. At high temperatures, heat transfer by convection is sharply reduced. Already at 30 0 C it is difficult, and at temperatures above 37 0 C it is impossible. In conditions of high humidity, heat transfer by evaporation of sweat is also difficult. At the same external temperature in the humid climate of the subtropics and tropics, the body tolerates the high temperature of the environment more difficult than in the dry (for example, in Central Asia or Egypt). In a steam bath, where the humidity reaches 90-97%, a person can hardly withstand a temperature of 45-50 ° C, and in a sauna, where the air is dry, at 100 and even 120 0 C one feels pleasure. Prolonged exposure to high temperatures with insufficient heat transfer leads to overheating of the body, an increase in body temperature above 40 ° C, an increase in weakness, disruption of the heart and central nervous system, thickening and a sharp increase in blood viscosity (due to the large return of water by the body), loss consciousness, convulsions. If you do not provide urgent assistance, a person can die from heat stroke.

A short-term effect of both cold (for example, wiping the body with snow, dipping into an ice hole after a hot bath, "winter swimming"), and high temperature does not cause thermoregulation disorders and is not only useful, but also pleasant. However, with prolonged exposure to cold, which is not compensated by an increase in heat production and a decrease in heat transfer, hypothermia of the body occurs, the body temperature decreases - and the body freezes.

With a decrease in body temperature to 31 -27 0 C, oxygen uptake and metabolism increase, strong trembling is observed. When the temperature drops below 19-20 0 C, oxygen uptake progressively decreases, the metabolic rate becomes less, trembling stops, the reaction to pain disappears, breathing weakens, consciousness is lost. At such degrees of cooling, a homoiothermic organism becomes poikilothermic, its temperature now already depends on the ambient temperature, and when it falls below 0 0 C, it freezes. If freezing occurs slowly and gradually, then it can be reversible, but rapid freezing is always irreversible, since ice crystals form in the cells, destroying cellular structures. At the same time, even a very significant decrease in body temperature, carried out carefully in a clinical setting, does not pose a mortal danger and is currently practiced in surgical operations on the heart, when blood circulation has to be stopped. The body's resistance to temperature influences, the expansion of the optimal temperature zone, as well as the increase in the body's resistance to hypoxia, can be achieved by gradually adapting it to changes in temperature conditions.

Excessive (too intense or prolonged) muscle activity can also be unfavorable for the body. Everyone knows the example of the Athenian warrior, whom the commander Miltiades sent from the Marathon battlefield to Athens to announce the victory over the Persians. The warrior ran 42 km 195 m, managed to say in the city agora: “We won” - and fell dead. And how many tragic incidents happen in everyday life! One middle-aged man ran for transport in order to get on a tram or bus, “suffocated” halfway, shortness of breath and weakness that appeared made him stop or take a calm step, and another, while running, fell with a myocardial infarction. Or a person lifted a heavy weight, overstressed, and he had an acute expansion of the heart and blood circulation was disturbed. And a trained athlete runs a marathon distance without falling dead at the finish line, and while running develops a speed that is inaccessible to a non-athlete, and lifts heavy weights that an untrained body cannot do. The fact is that intense or prolonged muscle activity is accompanied by a sharp increase in energy consumption. If in a state of bed rest a person expends 0.067 kJ/s, then during a marathon run - 1.0, and when running 100 m - 10.0 kJ/s. Naturally, this requires a very large expenditure of energy sources, and an increase in the absorption of oxygen necessary for their oxidation, and a significant increase in cardiac activity to transport the oxygen that has entered the body from the lungs to the muscles. The degree of increase in these physiological parameters, available to a trained athlete, cannot be mastered by a person who is not properly physically prepared. This means that the body can (and should) adapt to intense or prolonged muscular activity, but with the help of appropriate training.

Meeting with pathogenic microbes, one person does not get sick, another gets sick, but suffers the disease either mildly or in severe form, and the third dies from it. What determines the body's resistance to infections? This question is answered by an actively developing branch of medicine - immunology. The basis of immunity are antibodies synthesized by the body - special proteins belonging to the group of high-molecular globular proteins - immunoglobulins. The cause of the disease is pathogenic microbes or their metabolic products - toxins, which are of a protein nature. Antibodies, joining them, either neutralize them, or doom them to digestion by special cells - phagocytes (i.e., "devouring" cells). This process is far from simple. What stimulates the production of antibodies? Where are they produced? Why are they specific for some infections and inactive against others? Why, for example, inoculation against typhoid or smallpox does not create immunity against cholera or plague?

The production of antibodies is stimulated by the pathogen itself - a microbe, which, like all living things, has a protein nature. Microbial and any other foreign protein in immunology is called an antigen. Immune bodies (antibodies) are produced specifically directed against each specific antigen. But the blood contains a certain amount of non-specific antibodies, less effective, but capable of interacting with different antigens. These are nonspecific blood immunoglobulins that determine the overall resistance of the body to infections. It is this nonspecific immunity that explains why, having met with the same infection, one person falls ill and the disease proceeds in a severe form, another falls ill, but suffers the disease even on his feet, and the third does not get sick at all. How can this be explained? The formation of specific antibodies is the synthesis of new proteins that the body needs only when it encounters an infection, and outside of this they do not take part either in metabolism or in the construction of cellular structures.

We already know that the body synthesizes only those proteins whose structure is encoded in the cell genome. After all, the structures of antibodies against all possible foreign proteins unusual for the body cannot be provided for in it. This issue of “recognition” of antigens and the synthesis of specific antibodies against them is one of the most urgent and “hot” issues in immunology, and we will return to it later. In the meantime, we state that to resist infections, there is a specific and non-specific immunity, depending on the production of specific and non-specific immunoglobulins. It can increase as a result of an infectious disease or weaken under the influence of damaging environmental factors; it can also be obtained artificially by vaccination, that is, by introducing into the body the protein of killed microbes (vaccines), which does not cause disease, but leads to the production of specific antibodies.