BASICS OF MEDICAL BIOLOGY - 2012

The Biosphere as a System Ensuring Human Existence. Foundations of General Ecology and Human Ecology

The biosphere (from Greek bios – life, sphere – sphere) is the part of the Earth's envelopes (atmosphere, hydrosphere, lithosphere) inhabited by living organisms and actively transformed by them. The term "biosphere" was introduced by the Austrian geologist E. Suess. The Doctrine of the biosphere was developed by Academician V.I. Vernadsky (1863–1945). The biosphere comprises: 1) living matter, formed by the totality of organisms; 2) biogenic matter, created and transformed through the life activity of organisms (atmospheric gases, coal, oil, shales, limestones, etc.); 3) inert matter, formed without the participation of living organisms (products of tectonic activity, meteorites); 4) bio-inert matter, which is a joint product of the life activity of organisms and abiogenic processes (soil).

The BOUNDARIES OF THE biosphere are defined by the distribution range of organisms within the Earth's geo-envelopes – the atmosphere, hydrosphere, and lithosphere. The upper boundary of the biosphere is located at an altitude of approximately 20 km. The limiting factor for dispersal in the atmosphere is the intensity of ultraviolet radiation, which increases with altitude. Practically all living matter penetrating above the ozone layer of the atmosphere is destroyed. The biosphere extends into the hydrosphere to the full depth of the World Ocean, as confirmed by the detection of living organisms and organic deposits down to depths of 10–11 km. In the lithosphere, living organisms have been found to depths of approximately 7.5 km.

The totality of All living organisms on Earth is called living matter (according to V.I. Vernadsky's terminology). Living matter accounts for only about 0.01% of the Earth's crust by biomass, yet it plays a leading role in biogeochemical processes. The oxygen we breathe and the ozone layer protecting us from the harmful effects of cosmic radiation are created by living organisms; organisms also maintain the reserves of carbon dioxide in the atmosphere necessary for green plants. As a result of Photosynthesis, 115x10⁹ t of dry organic matter and 123x10⁹ t of oxygen are produced annually. Photosynthesis also involves 6x10⁹ t of nitrogen, 2x10⁹ t of phosphorus, and other elements over the course of a year. These figures demonstrate that living matter performs immense geochemical work, contributing to the transformation of the atmosphere, hydrosphere, and lithosphere on a Geological Time Scale.

In addition to the presence of living organisms, another crucial feature of the biosphere is the existence of biotic cycles (biogeochemical cycles) of chemical elements, primarily those termed biogenic. Through METABOLISM, energy exchange, reproduction, and wide dispersal, living organisms drive the biogenic migration of atoms. Over the existence of the biosphere, atoms of most elements have repeatedly passed through the bodies of living organisms. The activity of organisms determines the COMPOSITION OF THE atmosphere, the Composition and Structure of soils, and the composition of numerous substances in the hydrosphere. The global biotic cycle is carried out with the participation of all organisms inhabiting the planet. It consists in the Circulation of substances between the soil, atmosphere, hydrosphere, and living organisms. Utilizing inorganic substances, green plants harness solar energy to create organic matter, which serves as food for heterotrophic consumers. Other heterotrophic organisms break down the organic matter of dead bodies, converting it into Mineral Substances used by plants for new organic syntheses. Thus, The primary function of the biosphere is the circulation of matter and energy.

Human Evolution and The formation of human society took place in close connection with the environment. Humans are part of the biosphere, and it is impossible to separate them from it. However, humans represent a new, distinct factor. Humanity has introduced intellect, labor, and science into the biosphere, becoming a geological force that actively transforms it. Humans realized this mainly when not only the positive, but also the negative consequences of their activity on the biosphere became noticeable.

The new state of the biosphere, which consists in the rational regulation of relations between humans and nature, is called the noosphere (from Greek noos – mind). The term "noosphere" was first proposed in 1927 by the French philosophers E. Le Roy and P. Teilhard de Chardin. The DOCTRINE OF THE noosphere was created by V.I. Vernadsky, who attached great importance to science in The process of noosphere formation. Introducing scientific ideas about the biosphere and noosphere into the consciousness of students is one of the important tasks of medical biology as an academic discipline.

Class="center">Humanity as an Active Geological Force

The Emergence of human society contributed to the appearance of a new and most crucial anthropogenic factor associated with human presence and labor activity. Initially, human impact on the environment did not differ from that of other organisms. The means of subsistence drawn from nature were naturally replenished, and Metabolic waste products entered the general cycle of matter. Biosphere Homeostasis was not disrupted. Over time, population growth and the ever-increasing use of natural resources by human society evolved into a significant ecological factor that upset the prior balance in the biosphere.

At the present stage of our planet's existence, the most profound transformations in the biosphere are carried out precisely by humans; their activity affects climate, local topography, atmospheric composition, and the species and quantitative composition of flora and fauna. The Use of atomic energy and the testing of nuclear weapons have led to the accumulation of radioactive substances in the atmosphere, soil, and Water. The accident at the Chernobyl Nuclear Power Plant caused immense ecological damage. The severe consequences of this disaster have not yet been fully clarified, and its long-term effects remain impossible to predict.

By extracting ores from the bowels of the Earth, burning coal, oil, and gas, smelting metals, and creating synthetic substances that never existed in nature, humans significantly amplify the biogenic migration of elements. Over the course of human history, the total mass of living organisms has decreased, and over the past 300 years, the planet's biomass has diminished by approximately a quarter.

World history shows that humans, unfortunately, have not always wisely used – and still do not always wisely use – the natural wealth of our planet.

Natural resources are divided into renewable and non-renewable. Non-renewable resources include mineral deposits, the reserves of which are limited. Renewable resources are associated with the life activity of organisms. However, under irrational use, they too become depleted, which can trigger irreversible Changes in the biosphere. As a result of irrational human activity over recent centuries alone, many species of animals and plants have been exterminated. Inadequately treated industrial waste, when discharged into water bodies, destroys living organisms. Deforestation carried out without regard for reforestation leads to lower water levels in rivers and soil erosion. The reduction of forest areas, the growth of cities, roads, and other sealed surfaces that prevent water infiltration into the soil lead to soil water depletion. At the same time, the demand for water is growing, posing humanity with The Challenge of securing freshwater supplies.

A problem also arises regarding The amount of atmospheric oxygen. Atmospheric air is categorized as a renewable resource, but intensive industrial development and the reduction of the Earth's vegetation cover in recent decades exacerbate the negative Anthropogenic impact on the atmosphere. At the end of the 19th century, prior to rapid industrial development, carbon dioxide content was 0.029%, whereas today it averages 0.033%. Elevated concentrations of CO₂ in the atmosphere can lead to quite hazardous consequences: the greenhouse effect, global climate warming, and the melting of polar ice caps. If this trend continues, specialists calculate that by the end of the first quarter of the 21st century, the sea level will rise by 1–1.5 m, flooding vast land areas and potentially spelling catastrophe for many nations.

The balance of oxygen and Carbon dioxide is regulated primarily by the vegetation of forests and oceans. However, it must be noted that in many regions, more oxygen is consumed than produced. For instance, a modern passenger airliner consumes 50 tons of oxygen from the atmosphere during an 8–10 hour flight, while an automobile absorbs a human's annual oxygen ration over every 1,000 km traveled. The atmospheric oxygen content decreases annually. Considering that industrial development and population growth accelerate oxygen consumption, its percentage content could reach critical levels in 160–170 years.

Over the past three decades, fuel consumption has increased, leading to a rise in emissions of waste substances into the atmosphere (sulfur dioxide, nitrogen oxides, carbon monoxide, soot). As they move through the atmosphere, sulfur and nitrogen emissions, along with Hydrocarbons, transform into sulfuric and nitric acids, which precipitate onto the ground—sometimes hundreds or thousands of kilometers from their source—via rain, dew, snow, and frost.

In recent years, depletion of the ozone layer in the upper atmosphere has occurred, which previously protected all life from harmful solar radiation. Free molecules and compounds of chlorine and fluorine used in industry and daily life (such as chlorofluorocarbons) exert a particularly destructive effect on the ozone shield.

Changes in atmospheric composition carry major socio-economic consequences, harming the planet's flora and fauna as well as human health. Since the 1970s, many developed countries have taken measures to improve air quality in industrial areas; nevertheless, this is a global problem that can only be resolved through the active participation of all humanity. Although combating air pollution requires substantial economic efforts, these measures remain feasible and cost-effective compared to the total damage inflicted.

Today, humanity faces the prospect of an ecological crisis—an environmental state where, due to changes that have taken place, the environment may become unfit for life. Human activity leads to both positive and negative changes in the biosphere. Positive changes include the creation of new high-yielding crop varieties, animal breeds, and microbial strains, the artificial breeding of fish in seas and oceans, and the establishment of cultural biogeocenoses. Negative consequences stem from unregulated logging, mass harvesting of wild plants, pollution of water, air, and soil with industrial, agricultural, and domestic waste, and irrational land cultivation leading to erosion. Naturally, negative impacts on the biosphere must be curbed.

It is worth noting here that when V.I. Vernadsky spoke of the transition to the noosphere, he implied planned, scientifically grounded management of natural resources that ensured the replenishment of whatever humans disrupt within the cycle of matter.

Studies of air, water, and soil have made it possible to identify relatively ecologically comfortable territories—meaning conventionally clean areas with slight exceedances of pollution standards—and ecologically uncomfortable territories. Within the latter group, researchers distinguish: a) areas of extraordinary pollution with an elevated risk to human health; b) zones of ecological disaster. Ecological disaster zones comprise about 15% of Ukraine's entire territory: the 30-kilometer zone around Chernobyl and adjacent regions, including PARTS OF THE Kherson region and northern Crimea. The group of extraordinarily polluted regions includes the Donetsk region, the south of the Luhansk and Dnipropetrovsk regions, the Chernivtsi region, parts of the Mykolaiv and Zaporizhzhia regions, and eastern Crimea. According to the Ministry of Health of Ukraine, about 1 million people currently live in radiation-contaminated areas of the country, including 250,000 children.

As a result of mismanagement in Ukraine, many small rivers have effectively been destroyed. Only 50% of emission sources are equipped with Treatment facilities. About 19 billion cubic meters of wastewater are discharged annually into the republic's water bodies and drainage systems, with 41% left untreated. Industrial enterprises utilize about 50% of the Dnieper's annual runoff. Inadequate water treatment severely degrades water quality and may eventually lead to the loss of the Dnieper as a source of drinking water for 30 million people. Over the past 40 years, the salt content in the waters of the Dnieper has increased 1.5-fold, and in the Dniester and Southern Bug, 2-fold.

Today, only 4% of forests in Ukraine can be classified as natural, having preserved the biocenotic diversity of their flora and fauna.

The state of flora is closely linked to faunal diversity. Out of 270 bird species that once nested in Ukraine, 8 species have effectively disappeared over the past 40 years, and another 25 species are on the verge of extinction.

Adverse environmental conditions pose a serious threat to human health, with the incidence of malignant neoplasms increasing by 1.8% annually. The profile of oncological diseases has also shifted, now dominated by cancers of The Thyroid Gland, Oral Cavity, rectum, lymphatic and hematopoietic systems, respiratory Organs, prostate in men, and reproductive organs in women. Among children, tumors predominantly affect the lymphatic and hematopoietic Tissues, as well as the nervous and urinary systems. In men, tracheal, bronchial, lung, and gastrointestinal tumors are most common, whereas women are most frequently affected by breast and Reproductive System cancers.

The deterioration of children's health is a matter of particular concern. Their resistance to various infectious diseases is declining, the proportion of children with poor physical development is rising, and conditions stemming from Genetic Disorders and congenital birth defects are on the rise.

Biosphere Protection in International and National Programs

Population growth and, to an even greater extent, technological advancement compel scientists to reflect on the consequences of the uncontrolled exploitation of natural resources and the systematic pollution of the planet with substances harmful to living organisms. According to scientific forecasts, the ecological situation unfolding on Earth genuinely harbors the risk of severe and potentially irreversible disruptions to the biosphere unless human activities account for the laws of nature. Averting an ecological crisis requires pooling the efforts of all nations to safeguard the biosphere. In 1964, a specialized Organization—the International Biological Programme (IBP)—was established for an eight-year term. The mission of the IBP was to determine the biological productivity of natural and human-made terrestrial and aquatic PLANT AND ANIMAL communities. Following the completion of the IBP, the International Union of Biological Sciences launched a successor program entitled "Man and the Biosphere" (commonly abbreviated as MAB). The objective of the MAB is to unite researchers, sociologists, and other specialists to assess The impact of human activity on natural and anthropogenic ecosystems. The ultimate goal of the MAB is to forecast the future consequences of current human economic practices and to develop recommendations for the sustainable use and conservation of biosphere resources.

Environmental issues and their amelioration are overseen by specialized UN agencies: UNESCO, the Food and Agriculture Organization (FAO), the World Health Organization (WHO), and the International Atomic Energy Agency (IAEA). On the initiative of the UN, June 5 was designated as World Environment Day in 1972. Key international environmental agreements include the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter (1975), the Convention on Early Notification of a Nuclear Accident (1986), and the UN Convention on Biological Diversity (1992).

Environmental protection and the rational use of natural resources are governed by legislative acts. In Ukraine, these include the Constitution of Ukraine (1997), the Law of Ukraine "On Environmental Protection" (1991), the Law of Ukraine "On Ambient Air Protection" (1992), the Law of Ukraine "On the Animal World" (1993), the Subsoil Code of Ukraine, the Water Code of Ukraine, and the Forest Code of Ukraine. As a UN member state, Ukraine is a sovereign party to numerous international agreements on biosphere protection and actively collaborates with other nations to preserve our shared home—planet Earth.

Ecology and Human Ecology: Subject Matter, Objectives, and Methods

Ecology (derived from the Greek oikos meaning 'house' or 'dwelling', and logos meaning 'science') is the biological science that investigates the interactions among organisms and their communities, as well as with their environment. These interactions constitute the Subject Matter of ecology. The term "ecology" was first proposed in 1866 by the German Darwinian scientist Ernst Haeckel (1834–1919). The primary methods of ecology include field observations, experiments under natural conditions, and the modeling of processes and situations occurring in populations and biogeocoenoses using mathematical techniques.

Human ecology is the science that examines the interactions between humans and their environment. The term "human ecology" was coined in 1921 by Robert Park and Ernest Burgess. Its subject matter focuses on human-environment interactions at the level of the individual Organism and populations. The interactions between human society and the environment are studied by social ecology.

Population growth and rapid industrial development have led to environmental pollution, landscape degradation, the depletion of numerous plant and animal species, and a shrinking Gene pool. Consequently, a problem of paramount importance has emerged: the protection of nature and public health, alongside the rational use of natural resources. This challenge can be addressed by studying the structure and functioning of populations, biogeocoenoses, and THE BIOSPHERE AS a whole, given that the biological species Homo sapiens exists in the form of populations, which in turn form part of biogeocoenoses and the biosphere. These matters are investigated by ecology. Recognizing the critical need to solve environmental problems that affect every resident of the planet has drawn the attention not only of biologists, but also of specialists from diverse scientific fields and the general public, with interest being particularly strong among youth. Under these conditions, the ecologization of the educational process becomes essential. Its goal is to instill in future physicians an ecological mindset—a deep understanding of the inextricable unity between humanity and nature, and of human well-being's dependence on the state of the environment. Within medical training, The Role of ecology is continually expanding due to its close connection with modern medical challenges.

The Environment as an Ecological Concept

The environment is an indispensable component of all living systems. Organisms and their environment exist in continuous interaction, functioning as a unified whole; an organism cannot exist outside of its environment. The environment is defined as the aggregate of all external elements that act upon a living organism within its habitat. The types of environments include terrestrial-air, aquatic, soil, and living organisms themselves as a specialized habitat. Environmental elements that exert a specific influence on organisms are called ecological factors, which are categorized into abiotic, biotic, and anthropic (anthropogenic) factors. Abiotic factors pertain to non-living nature (humidity, Temperature, light, soil, topography), biotic factors to living nature, and anthropic factors to human influence. Although numerous factors act upon an organism simultaneously, only certain ones are vital; these are termed limiting factors, whose absence, or whose presence below or above critical levels, makes the existence of the organism impossible. Each ecological factor is characterized by an intensity of action. The intensity most favorable for vital activity is called the optimum. The threshold intensities beyond which an organism cannot survive are termed the lower and upper limits of tolerance (critical minimum and maximum points). The range of a species' adaptability to environmental conditions is known as its ecological valence. Species with a high ecological valence can withstand significant fluctuations in external conditions, whereas those with a low valence exist only within narrow limits. The former are termed eurytopic (from Greek eurus meaning 'broad'), and the latter stenotopic (from Greek stenos meaning 'narrow'). A single species may be eurytopic with respect to certain factors and stenotopic with respect to others.

Human ecology intersects with many aspects of contemporary medicine: human adaptation to adverse or extreme conditions, the characterization of health norms and pathology, disease prevention, and the scientific organization of life-support systems for human populations. The integration of numerous biomedical disciplines has given rise to ecological medicine.

The recent formation of a new integrative science—ecological genetics—which is grounded in the interplay between genotype and environment and investigates hereditary differences in human responses to specific environmental factors, has made it possible to distinguish Three types of human habitats:

1. A healthy or comfortable environment—a complex of factors providing living conditions in optimal combinations and in harmonious interaction with human well-being, allowing individuals to thrive.

2. An unhealthy or uncomfortable environment—characterized by the Deficiency of certain life-support factors and a disruption in the harmony of human-nature interactions. Factors exerting negative impacts on the organism (such as ionizing radiation, chemical agents, and biological factors) emerge, predisposing The Human Body to disease under these conditions.

3. An extreme environment—characterized by distorted specific life-support media and the operation of extraordinary factors, leading to The Development of maladaptation diseases.

The process of organismal adaptation depends on living conditions, which are classified as adequate or inadequate. Adequate conditions are characterized by a complete correspondence between environmental conditions and the hereditary constitutional Properties of the organism at a given moment. Inadequate conditions represent a mismatch between environmental conditions and the organism's hereditary constitutional traits at a specific stage of its existence.

Social and biological Aspects of Population ADAPTATION TO ENVIRONMENTAL Conditions

Adaptations refer to the adjustments organisms make to specific environmental conditions, ensuring their survival and reproduction. Adaptations also denote the evolutionary process of acquiring fitness for particular environments. Developed on The basis of a hereditary program under the control of natural Selection, adaptations to specific conditions are always relative. All organisms possess the adaptive capacity to change within the limits of their reaction norm while maintaining homeostasis.

Initially, prehistoric humans continued to adapt to external conditions by altering their morphophysiological Functions. Over time, biological adaptation was superseded by social adaptation, which is fundamentally rooted in labor. Social adaptation is an active human engagement with the surrounding habitat: whereas animals adapt their bodies to the environment, humans use labor to adapt the environment to their existence, with the level and range of adaptation being determined by the stage of productive development.

The human environment encompasses natural and social components, or natural and artificial environments, whose elements intertwine and interact. This complex of elements possesses distinct characteristics across various geographic and economic Regions of the planet. According to the World Health Organization Constitution (1968), the integral criterion for environmental quality regarding its suitability for human habitation is the health status of the population, defined as a state of complete physical, mental, and social well-being, rather than merely the absence of disease or infirmity.

Elements of the artificial environment predominate in human surroundings. By creating an artificial environment around themselves, humans—unlike other species confined to specific geographic ranges—have been able to populate the entire planet. The natural environment is incorporated into the human surroundings in a more or less humanized form, tailored to human needs. Virtually all environments inhabited by human populations represent artificial, human-made ecosystems known as anthropogenic ecosystems or anthropobiogeocoenoses, with cities, rural settlements, and transport networks constituting The most significant Examples.

Factors from both natural and artificial environments continuously influence humans. Because adaptations are forged in response to factors from both spheres, they bear a dual biological and social character rooted in Human biosocial nature. Currently, social mechanisms of adaptation hold paramount importance for enabling humans to inhabit new environments and improve conditions in existing ones; these are implemented through Sanitary and hygienic measures, such as constructing housing and other buildings, designing appropriate clothing, organizing food and water supplies, and establishing rational work-rest regimens. Because humans possess a social essence and individual identity, social adaptations are complemented by psychological adaptations. Alongside survival and reproduction, individual and population-level human adaptations ensure the fulfillment of social functions, chief among which is socially useful and highly productive labor.

Adaptation is the aggregate of physiological reactions underlying an organism's adjustment to changing environmental conditions, directed at maintaining the relative constancy of its internal milieu—homeostasis. The adaptive process involves vital biological mechanisms, including anatomical-physiological, biochemical, and behavioral responses to fluctuating environmental factors.

A distinction is made between short-term and long-term adaptations. An example of short-term adaptation is the acceleration of Heart rate and increased respiratory rate during a specific short-term physical exertion. Prolonged physical exertion leads to myocardial hypertrophy, which is an example of long-term adaptation.

The strategy of human adaptive behavior can vary significantly. Accordingly, the following functional types of constitutional response are distinguished:

1. "Sprinter" – characterized by strong yet short-lived physiological responses. The mobilization reserve is small. Such individuals are unsuited to prolonged physical exertion.

2. "Stayer" – the body is capable of withstanding stable, prolonged, and monotonous physical exertion. The body tolerates the burden consistently.

3. "Mixture" (or Mixed) – an intermediate type of constitutional response featuring an optimal adaptive reaction pattern.

Human Adaptive Ecotypes

As a result of natural factors that vary across different regions of the planet, specific human adaptive types have formed throughout human history and persist to this day. An adaptive type is a complex of features (morphofunctional, biochemical, immunological) that ensure an optimal biological fitness of humans to a specific physical environment. The existence of various adaptive types indicates significant human ecological plasticity, which is believed to have been one of the Prerequisites for the global dispersal of humankind. Human adaptive types formed independently of race in connection with specific ecological challenges on the basis of the corresponding gene pool. The process involved the formation of populations whose gene pools corresponded to local conditions better than the gene pool of the species as a whole. The following human adaptive types are distinguished: Arctic, tropical, temperate, desert, and high-altitude.

The Arctic adaptive type formed as an ADAPTATION TO A humid, cold climate and oxygen deficiency. It is characterized by a relatively strong Development of the musculoskeletal body component, large chest dimensions, a high Hemoglobin level, a relatively large volume occupied by Bone Marrow, an increased mineral content in bones, a high Blood protein and Cholesterol content, and an enhanced ability to oxidize fats. Arctic indigenous populations have a greater body mass than southerners. A larger mass contributes to better heat retention, a role also played by the layer of subcutaneous fat. In body proportions, a decrease in leg length relative to arm length is observed. Overall, the Arctic type is characterized by elevated Energy Metabolism, which maintains stable parameters under conditions of hypothermia. There are also peculiarities in thermoregulatory mechanisms. For instance, under the same degree of cooling, Canadian Indians experience a sharp drop in Skin temperature while their metabolic rate changes insignificantly, whereas incoming white populations show a smaller degree of skin temperature reduction accompanied by strong shivering, meaning metabolism is intensified.

The tropical adaptive type. In subtropical and tropical regions, an exceptionally wide Variability of population groups is observed. Both the shortest and tallest populations live here. Nevertheless, environmental factors, especially climatic ones, have contributed to the development of Specific features of the tropical adaptive type. In Negroids, these include an elongated body shape, reduced Muscle mass, a relative decrease in body mass coupled with an increase in limb length, a reduced chest circumference, more intense sweating due to an increased number of Sweat Glands per 1 cm² of skin, low basal metabolic and fat synthesis rates, and a reduced cholesterol concentration.

The temperate adaptive type occupies an intermediate position in somatic parameters between the indigenous inhabitants of the Arctic and tropical regions.

The desert adaptive type. According to UNESCO data, deserts make up about one-fifth of the area of all continents. The ecological factors under The Influence of which the adaptive ecotype of desert dwellers formed include high solar radiation intensity (temperatures in the shade reach +50 °C), low precipitation, and dry air. Under conditions where the body receives a large amount of heat, the main physiological task is to increase heat dissipation to maintain homeostasis. This task is accomplished through the evaporation of water. Each gram of evaporated liquid carries away 2.43 kJ (0.58 kcal) of heat. Natives of Central Africa, Southern India, and other regions with a hot and dry climate are distinguished by long, slender limbs and a small body mass, which provides a larger surface-to-volume ratio—and the larger the surface area, the greater the heat dissipation. To compensate for water loss caused by increased sweating, There is a need to increase fluid intake. The local population is better adapted to these conditions, consuming less water than people arriving from the temperate zone. Under high-temperature conditions, the requirement for Proteins and fats decreases because such food has a high energy value and, furthermore, increases thirst. A diet with a predominant carbohydrate content increases the body's endurance.

The high-altitude adaptive type. High-altitude conditions are extreme for humans in many respects. They are characterized by low atmospheric pressure, reduced partial pressure of oxygen, cold, and a relatively monotonous diet. The main ecological factor under the influence of which this human ecotype formed is believed to be Hypoxia. Regardless of climatic zone, racial, or ethnic affiliation, high-altitude residents exhibit the following features: an elevated basal metabolic rate, relative elongation of the long tubular BONES OF THE Skeleton, a broad chest, and an increase in the oxygen capacity of the blood due to an elevated erythrocyte count, hemoglobin content, and the relative ease of its transition to oxyhemoglobin.

Human Adaptations to extreme Conditions and THE CONCEPT OF Stress

Social adaptations form the basis of human adaptation to living conditions. However, an important role also belongs to biological adaptations, which depend on the state of defense mechanisms. They are particularly manifest under extreme conditions—both natural (the Arctic, high altitudes) and artificial, such as in large cities with polluted air, noise, vibration, and high population density. For instance, people who arrive to work in the Polar region from the temperate zone experience prolonged unhealthy states that are exacerbated, for example, by changes in polar day and night. These manifest as elevated blood pressure and accelerated pulse, after which blood pressure drops, sometimes to 70/30 mm Hg. These phenomena lead to reduced working capacity. After a certain time, functional parameters normalize in some individuals while remaining altered in others, though working capacity and well-being are restored—that is, human acclimatization to the new conditions takes place. The criterion for human acclimatization is the restoration of a high level of working capacity.

Human adaptation to extreme conditions can take the form of stress. The widely known theory of stress by the Canadian scientist Hans Selye defines stress as a complex of the body's adaptive reactions aimed at overcoming the harmful effects of extreme factors and temporarily increasing its nonspecific resistance. The factors that cause stress can be diverse: muscular and nervous overstrain, emotional arousal, trauma, infection, and abrupt changes in environmental conditions. Each of these factors elicits a specific reaction, alongside a nonspecific stereotyped response in the form of stress. General stress has three Stages of development: 1) the alarm stage, during which the body's resources are mobilized; 2) the stage of increased resistance; and 3) the stage of exhaustion of the body's defensive reserves.

In The First stage—the alarm stage—receptors are stimulated, the sympathoadrenal system is excited, and adrenaline secretion by The adrenal medulla is enhanced. This immediately exerts a strong effect on the body: blood sugar levels rise, heart contractions intensify, and blood pressure increases. All of this enhances motor activity, particularly intensive performance. In the second stage—the stage of increased resistance—adrenaline, acting via the Hypothalamus, stimulates The production of a neurohormone (liberin) by specialized Cells. This neurohormone affects the anterior Pituitary Gland, which secretes adrenocorticotropic hormone (ACTH) and enhances the production of Adrenal Cortex Hormones that increase the body's resistance to stressors: metabolic processes are activated, fat is mobilized from fat depots, and the blood content of Amino Acids and glucose increases. The Third Stage—exhaustion—occurs upon exposure to an intense stimulus or prolonged exposure to a weak stimulus, as well as when defense adaptation mechanisms are insufficient; at this point, the strain is so high that, despite hypertrophy, the adrenal cortex is unable to produce the required amount of hormone, and stress acquires a pathogenic character—meaning a breakdown of homeostasis occurs.

According to Selye, Aging is the result of all the stresses the body undergoes throughout its life.

Diseases of maladaptation develop as a consequence of stress. Their main cause lies in an improper hormone ratio or a shift in the body's reactivity caused by prior illnesses. A person experiences psycho-emotional shifts, neurotization, psychoses, and other disorders. A mandatory condition in this situation is complete physical and emotional rest against the backdrop of drug therapy.

Ecological Situation in Ukraine

The ecological situation in the world becomes more complex with each passing year, and this applies to Ukraine as well. Industrial sources annually emit over 10 million tons of toxic chemical compounds into the atmosphere and discharge 2.5 billion m³ of polluted wastewater into water bodies. In 43 cities, home to 30% of the country's population, the level of air basin pollution significantly exceeds maximum permissible concentrations. Annually, 170 thousand tons of pesticides and 150 thousand tons of mineral fertilizers are applied to Ukrainian soils. These introduce 1,800 tons of lead, 400 tons of cadmium, 2,200 tons of zinc, and 200 tons of copper into the soil. The pollution of water bodies also causes concern. Many chemical pollutants possess carcinogenic and mutagenic properties. The health status of the population has deteriorated. The ecological situation became particularly acute in connection with the accident at the Chornobyl Nuclear Power Plant (ChNPP), which occurred in 1986. The accident had a severe impact on public health. A sense of Shock and fear spread worldwide. In Ukraine, 3 million 427 thousand people were affected by the consequences of the ChNPP accident, including 1 million 260 thousand children. More than 36 thousand hectares of Ukraine's territory are contaminated with radionuclides with a cesium-137 density exceeding 1 Ci/km². The primary illnesses recognized as being associated with the consequences of the ChNPP accident are predominantly oncological diseases, as well as Disorders of the circulatory and nervous systems. The mortality rate among the population affected by the ChNPP accident has increased 3-fold, and morbidity 6-fold.

The search for medicinal products aimed at the pharmacological correction of the negative IMPACT OF ENVIRONMENTAL factors on the human body is one of the tasks of ecological pharmacy. A necessary condition for preserving public health is ecological standardization—ensuring ecological safety aimed at creating ecologically clean food, safe drinking water, and a clean environment.

State Program for the Conservation of Biodiversity of Ukraine for 2007–2025

✵ to prevent the irreversible loss of part of the gene, demo, ceno, and ecofools (gene pool, demographic, biocenotic, and ecophysiological reserves), and ensure the maintenance of ecological balance on the territory of Ukraine;

✵ to introduce elements of ecologically safe, sustainable use of natural resources into economic practice;

✵ to optimize the natural resource potential—primarily recreational, tourist, and bio-resource potential, especially in the Carpathians, Crimea, and Polissia—and reorient the relevant economic sectors toward ecologically targeted and economically more profitable management in the long term;

✵ improve regional infrastructure and balance socio-economic development, reduce unemployment and social tensions;

✵ improve public health;

✵ refine the economic mechanism and conceptual approaches to biodiversity conservation, and improve the financing of biodiversity preservation measures;

✵ enhance the spatial and qualitative indicators of biodiversity, which will foster positive environmental changes at the local and regional levels (climate, water quality, and water management, particularly of small rivers);

✵ establish a coherent ecological network that will facilitate, in particular, the restoration of biogeochemical cycles, the expansion of habitats for wild plants and animals, and increase the survival probability of vulnerable animal populations and plant communities;

✵ mitigate the risks of desertification, dehumification, and land degradation;

✵ improve The system of environmental education, training, and public awareness;

✵ account for risks associated with the use of living modified organisms in biotechnological Applications;

✵ restore degraded ecosystems and promote the conservation of endangered animal species;

✵ prevent the Introduction of alien species that may adversely affect native species, ecosystems, or public health;

✵ systematize regulatory and legal documents and harmonize them with international legal acts;

✵ coordinate the activities of executive authorities, local self-government bodies, business entities, and civil society organizations in the field of biodiversity conservation;

✵ intensify international cooperation on biodiversity preservation and ensure the fulfillment of Ukraine's obligations in this area.