In connection with the socialization of man, his biological role is gradually losing its significance. This happens not because people have reached the highest levels of development, but because they deliberately distance themselves from their actual “foundation” (biosphere), which has enabled people to develop and build a modern society. But the body as a biological system cannot exist outside the biosphere, and therefore should only be considered together with it.
Population and society
Any society is an independently regulated population, a modern analogue of a reasonable biological system (BS) within the biosphere. And man is, first of all, the product of the evolution of the BS, and not the result of the development of a social society, which is secondary. Strictly speaking, society is a certain private example of a population, which is also a BS located only one level above a living organism.
From the point of view of biology, this term characterizes a system of organs and tissues built into the living shell of the planet, which has its own mechanisms of influence on habitats and protective reactions. Considering the body as a biological system, it is easy to identify the basic mechanisms of its life, adaptation and regulation of its functions. And in the framework of this publication, the human body will be considered as a whole system from the point of view of its criteria.
Terminology
A system is a large collection of some interdependent elements that form a certain integrity (structure) that has undergone a long evolution during its formation.
Biological systems are indivisible sets of interconnected elements that create a living shell of the planet and are included in it, playing a critical role in its existence. Examples of biological systems: cell, organism, macromolecules, organelles, tissues, organs, populations.
An organism is a complexly organized, independently regulated and actively functioning system consisting of organs and tissues or represented by one biological system, forming one object of living nature. The body actively interacts with higher-order biological systems (with population and biosphere).
Regulation is an ordering, submission to strict rules, creation of conditions for their implementation and control. In the context of the human body, the term should be considered as a process of normalization of body functions.
Universal structure
To consider the human body as a biological system (BS), it is necessary to highlight its basic properties and correlate them. So, the main property of BSs is their structure: they all consist of organic molecules and biopolymers. It is noteworthy that inorganic substances are also presented in the BS, which are attributes of inanimate nature. However, they are not formative for a biological molecule, organelle, cell or organism, but only integrate into these systems.
Orderliness
A high degree of ordering is the second property of systems. The so-called hierarchy is very important for the functioning of the biosphere for the reason that its entire structure is built on the principle of complicating the simple and combining the elementary. That is, the more complex components of the living shell of the earth (biological systems) consist of smaller ones located lower in the hierarchy.
A particular example is the evolution of life from a macromolecule to an organic polymer, and then to an organelle and subcellular structure, from which tissue, organ and organism are later formed. As a holistic biological system, such a hierarchical structure allows you to form all levels of wildlife and track the interaction between them.
Integrity and Discreteness
One of the most important properties of any BS is its simultaneous integrity and discreteness (partiality, component nature). This means that any living organism is a biological system, an integrated whole formed from autonomous components. Autonomous components themselves are also living systems, only located lower in the hierarchy. They can exist autonomously, but within the framework of an organism they obey its regulatory mechanisms and form an integral structure.
Examples of simultaneous integrity and discreteness can be found in any systems of different levels. For example, the cytoplasmic membrane as a whole structure has hydrophobicity and lipophilicity, fluidity and selective permeability. It consists of lipoprotein macromolecules that provide only lipophilicity and hydrophobicity, and of glycoproteins responsible for selective permeability.
This is a demonstration of how the combination of discrete properties of the components of a biological system provides functions of a more complex higher structure. An example is also a holistic organelle consisting of a membrane and a group of enzymes that inherited their discrete qualities. Or a cell that is able to realize all the functions of its constituent components (organelles). The human body as a single biological system also obeys this dependence, as it demonstrates common qualities that are particular to discrete elements.
Energy exchange
This property of the biological system is also universal and can be traced at each hierarchical level, from the macromolecule to the biosphere. At each specific level, it has various manifestations. For example, at the level of macromolecules and pre-cellular structures, energy exchange means a change in the spatial structure and electron density under the influence of pH, electric field or temperature. At the cell level, energy exchange should be considered as metabolism, a combination of processes of cellular respiration, oxidation of fats and carbohydrates, synthesis and storage of macroergic compounds, removal of metabolic products to the outside of the cell.
Body metabolism
The human body, as a biological system, also exchanges energy with the surrounding world and transforms it. For example, the energy of the chemical bonds of carbohydrate and fat molecules is effectively used in the cells of the body for the synthesis of macroergs, from which it is easier for organelles to extract energy for their life. In this demonstration, there is a transformation of energy and its accumulation in macroergs, as well as the implementation of ATP by hydrolysis of phosphate chemical bonds.
Self regulation
This characteristic of biological systems means the ability to increase or decrease its functional activity depending on the achievement of any conditions. For example, if a bacterial cell experiences starvation, then it either moves toward the source of nutrition, or forms a spore (a form that will allow maintaining vital activity until the living conditions improve). In short, the body as a biological system has a complex multilevel system for regulating its functions. It consists of:
- precellular (regulation of the functions of individual cellular organelles, for example, ribosomes, nuclei, lysosomes, mitochondria);
- cellular (regulation of cell functions depending on external and internal factors);
- tissue regulation (control of the growth rate and reproduction of tissue cells under the influence of external factors);
- organ regulation (the formation of mechanisms of activation and inhibition of the functions of individual organs);
- systemic (nervous or humoral regulation of functions by higher organs).
The human body as a self-regulating biological system has two main regulatory mechanisms. This is an evolutionary older humoral mechanism and a more modern nervous one. These are multilevel complexes capable of regulating the metabolic rate, temperature, pH of biological fluids and homeostasis, the ability to defend oneself from dangers or provide aggression, realize emotions and higher nervous activity.
Levels of humoral regulation
Humoral regulation is the process of accelerating (or slowing down) biological processes in organelles, cells, tissues or organs under the influence of chemicals. And depending on the location of their “target”, cellular, local (tissue), organ and organism regulation is distinguished. An example of cell regulation is the effect of the nucleus on the rate of protein biosynthesis.
Tissue regulation is the release by the cell of chemicals (local mediators) aimed at suppressing or enhancing the functions of surrounding cells. For example, a cell population experiencing oxygen starvation, allocates angiogenesis factors that cause the growth of blood vessels towards them (in depleted areas). Another example of tissue regulation is the release of substances (keilons) that can suppress the rate of cell reproduction in a certain place.
This mechanism, unlike the previous one, is an example of negative feedback. It is characterized as an active effect of the cell population, designed to suppress any process in biological tissue.
Supreme humoral regulation
The human body as a single self-developing biological system is an evolutionary crown that implements the highest humoral regulation. It became possible due to the development of endocrine glands capable of secreting hormonal substances. Hormones are called specific chemicals that are secreted by the endocrine glands directly into the bloodstream and act on target organs located at a great distance from the synthesis site.
Higher humoral regulation is also a hierarchical system, the main organ of which is the pituitary gland. Its functions are regulated by the neurological structure (hypothalamus), which is located above the others in the regulatory hierarchy of the body. Under the influence of nerve impulses of the hypothalamus, the pituitary gland secretes three groups of hormones. They enter the bloodstream and are carried by it to target organs.
In tropic pituitary hormones, the target is the downstream hormonal gland, which, under the influence of these substances, releases its mediators that directly affect the functions of organs and tissues.
Nervous regulation
Regulation of the functions of the human body is mainly realized through the nervous system. It also controls the humoral system, making it, as it were, its structural component, capable of more flexibly affecting the functions of the body. Moreover, the nervous system is also multilevel. In humans, it has the most complex development, although it continues to improve and modify extremely slowly.
At this stage, it is characterized by the presence of functions responsible for higher nervous activity: memory, attention, emotionality, intelligence. And, perhaps, one of the main properties of the nervous system is the ability to work with analyzers: visual, auditory, olfactory, and others. It allows you to remember their signals, reproduce them in memory and synthesize new information on their basis, forming also sensory experience at the level of the limbic system.
Levels of nervous regulation
The human body as a single biological system has several levels of nervous regulation. It is more convenient to consider them according to the gradation scheme from lower to higher levels. Below the others is the autonomic (sympathetic and parasympathetic) nervous system, which regulates its functions regardless of the higher centers of nervous activity.
It functions due to the nucleus of the vagus nerve and the adrenal medulla. It is noteworthy that the lowest level of nervous regulation is located as close to the humoral system as possible. This again demonstrates the simultaneous discreteness and integrity of the organism as a biological system. Strictly speaking, the nervous system transmits its signals under the influence of acetylcholine and electric current. That is, it half consists of a humoral information transfer system, which is observed in synapses.
Higher nervous activity
Above the autonomic nervous system is the somatic, which consists of the spinal cord, nerves, trunk, white and gray matter of the brain, its basal nuclei, limbic system and other important structures. It is she who is responsible for higher nervous activity, work with analyzers of the sensory organs, systematization of information in the cortex, its synthesis and development of verbal communication. Ultimately, it is this complex of biological structures of the body that is responsible for the possible socialization of man and the achievement of his current level of development. But without low-level structures, their appearance would be impossible, as the existence of a person outside the usual habitat is excluded.