Physiological functions

Physiological functions are the manifestations of life, have adaptive value. Performing different functions, the body adapts to the external environment or prisposoblen environment to their needs.
Every physiological function of cells, tissue, organ, or organism as a whole is the result of the entire history of the species and individual development of living beings - their Philo - and ontogenesis. In the process of this development there are certain function of living structures and there is a qualitative and quantitative change. Therefore, the important task of physiology is the study of functioneaza, i.e. the emergence and development of each individual function.
The main function of a living organism is metabolism and energy. This process consists in combination of chemical and physical changes in the transformations of materials and energy, constantly and continuously occurring in the body and in all its structures.
Metabolism, or metabolism, is a necessary condition of life. He distinguishes living from the dead, the world of living beings from the inorganic world. Changes of matter and energy transformation happen in the inorganic world; however, there is a fundamental difference of these processes in a living organism and nonliving nature. The essence of this difference is perfectly formulated F. Engels in "Dialectics of nature": "And inorganic solids can happen in similar metabolism that occurs virtually everywhere, because everywhere occur, albeit at a very slow way, chemical action. But the difference is that in the case of inorganic bodies metabolism destroys them, in the case of organic bodies it is a necessary condition for their existence." Life is only possible up until there is an exchange of substances that supports the existence of living protoplasm and leads to its self-renewal. Termination of metabolism is the consequence of the death, the destruction of protoplasm and irreversible breakdown of specific chemical, primarily protein compounds.
With metabolism associated all other physiological functions, whether growth, development, reproduction, nutrition and digestion, breathing, the secretion and selection of waste products, movement and reaction to changes in the external environment, etc. the Basis of any physiological functions is defined set of transformations of substances and energy. This equally applies to the functions of a separate cell, tissue, organ, or organism as a whole.
When performing any functions in the physical and chemical processes and chemical transformations in the cells of the body undergoes structural changes. In some cases they can be detected by microscopic examination. Valuable data while getting through cyto - and histochemical methods, the essence of which is that by means of special reagents determine the localization in the cells and tissues of some substances and their changes in the implementation of various functions. In other cases, changes of cellular structures can not be detected with the help of an optical microscope, because often they are submicroscopic, i.e. outside the microscopic vision. To install such changes can electron microscope with greater resolution and higher magnification than optical microscopes (electron microscope magnifies the image in 100 000-200 000 times). Thanks electron microscopy managed to establish submicroscopic changes in muscle cell at its reduction, in the nerve ending in the transmission of nerve impulses innervated authority. The result histochemical and electron microscopic studies have confirmed the view that every physiological function is intrinsically linked to changes in the structure of cells. These changes in the structure, as a rule, are reversible, quickly recovering. Only in some cases, they may be irreversible. For example, let us point out that there are two types of secretions, i.e. the allocation of cells of various substances: when one of them, despite the allocation of cells certain products, its integrity is preserved, and the other is the destruction of cells or the entire cell.
For understanding the nature of the processes that underlie the various functions of the body and its organs and cells, it is important for the study of very small changes of metabolism and energy derived moreover, in very short periods of time (in milliseconds and even in microseconds). This is because with such quantitatively insignificant processes related to many major functions of cells. So for physiology is extremely important to the development of more sensitive and accurate methods of research, allowing to define and measure very small and quickly taking place physical and chemical processes. In this respect a lot for physiology given the use of modern achievements of physics, chemistry and technology, which had armed scientists new methods of research. So, increase the sensitivity of electric methods of temperature measurement allowed to determine the heat buildup in the nerve fiber with the passage of one nerve impulse; temperature increases by 2·10-6° (two million shares of degree!). It showed that the nervous system is associated with increased, though minor, metabolism. The use of electronic amplifiers and oscilloscopes made possible the measurement of electric potential difference, equal to microvolts, in the nerve fibers and their endings, and it revealed the mechanism of influence of certain nerves in the body tissues. New chemical techniques has allowed to define the structure of many chemical compounds produced in the body in small amounts and act on it at a concentration of 1 x 10-8, which allowed a deeper understanding of the chemical interaction of cells and tissues in the body.
Manifesting itself in physical and chemical, including any mechanical changes, the functions of the body cannot be reduced to any one of them, as life functions are complex interacting population, the unity of all these processes. Studying every living thing: single cells or highly complex organism, physiologist obliged to synthesize the data of physical, chemical and morphological studies, because the body is a higher unity linking in himself into one mechanics, physics and chemistry" (F. Engels).