Physiology - what is it? History and Basics of Physiology
Among the branches of biology and medicine dealing withthe study of the human body, a special place is occupied by physiology. What is the physiological system, by what principles does it function and what is responsible for - these issues were investigated by well-known Russian scientists: IP Pavlov, PK Anokhin, IM Sechenov. In our work, we will consider the stages of the formation and formation of physiology. Further we will get acquainted with the directions studying the metabolic processes not only of the human body, but also of animals and plants. Also we will give examples that confirm the practical importance of science about the functions of systems, organs and cells of the human body for the development of medicine and the preservation of health.
History of Physiology
One of the first researchers who studiedpeculiarities of human metabolism, was the founder of medicine - Hippocrates. English physician Harvey, who lived in the 17th century, established the principles of blood circulation in a closed system of blood vessels and opened a large circle of blood circulation. The Italian physicist and natural scientist L. Galvani conducted experiments that clarified the nature of nerve impulses, and laid the foundations of neurophysiology. This branch of science was further developed thanks to the works of MI Sechenov, VM Bekhterev, PK Anokhin. A significant contribution to the study of the functions of the respiratory system was made by chemists: A. Lavoisier and D. Priestley.
The place of physiology in the system of biological disciplines
Studying the life manifestations of not only cells,organs and tissues, but also the entire human body as an open biological system, the foundations of physiology combined a whole cohort of special - applied - branches of biology. These include biochemistry, cytology and histology. They consider the metabolic reactions at the molecular, cellular and tissue levels. This is followed by embryology and genetics, which study the functions of reproduction and transmission of hereditary properties. And finally, the most significant is the relationship of physiology with anatomy, without which it is impossible to correctly determine the processes occurring in each of the functional systems: the nervous, endocrine, circulatory, etc.
Pavlov's contribution to the study of digestion processes
A scientific definition of what physiology is, you canformulated as follows: it is a science that studies the vital functions of all systems entering the body. Biochemical reactions occurring in the human digestive tract, as well as the mechanisms that regulate them, were determined by the outstanding Russian scientist IP Pavlov. His technique of imposing fistula helped to uncover the secrets of the duodenal glands. Stages of digestion in the stomach were also established and the chemical composition of the gastric juice, which was released even before the chyme enters the cavity of the organ, was studied. It became clear what the physiology of digestion is.
Due to the unique in its accuracy operationson animals, the scientist presented a complete clinical picture of the salivary gland, liver, and stomach functioning. The production of enzymes by their secretory cells occurs under the influence of excitation of the centers of unconditioned reflexes in the trunk portion of the brain.
The scientist also uncovered neuro-humoral mechanismsregulation of digestion processes, for which in 1904 was awarded the Nobel Prize. Pavlov's research was of decisive importance for answering the question "What is the physiology of man and what is its role in the system of biological disciplines?".
Practical significance of the works of IM Sechenov
Brilliant discoveries of the founder of the doctrine ofinhibition in the central nervous system of Ivan Mikhailovich Sechenov still serve as a theoretical basis for studying the processes of thinking, memory, speech. The scientist substantiated the main directions of studies of cerebral reflexes and determined the presence of a local inhibitory center in the thalamus of the intermediate brain. According to IM Sechenov's ideas, a special role in the process of irradiation of inhibitory processes is played by special molecules - transmitters synthesized in the body and accumulated in the blood plasma.
The scientist was one of the first to define what isphysiology of a sick organism. It served as the basis for medicine in the question of the correct diagnosis and the choice of the optimal methods of treatment. IM Sechenov's doctrine of feedback in the reflex activity of the brain was a prerequisite for the creation of the science of cybernetics.
The concept of functional systems
Life-activity of the human body as the mostperfect biological system of the open type goes far beyond the framework of reflex reactions. A well-known Russian scientist PK Anokhin created a theory explaining the maintenance of the constancy of the internal environment with the help of a complex of physiological organs and systems. Their well-coordinated work preserves the level of homeostasis that corresponds to a healthy organism, and is regulated by complex behavioral acts. The researcher's research helped to answer the question of what the physiology of higher nervous activity was, confirmed the thoughts of IM Sechenov on the role of the higher centers of the cerebral cortex in providing a choice of settings, achieving the goal and ways of motivating human activity.
In our body there are functionalsystem of two levels. The first includes mechanisms that promote the maintenance of homeostasis with the help of neurohumoral regulation. They provide a normal level of blood sugar, blood plasma composition, blood pressure, etc. The second system supports the life support of the organism by interacting with the habitat through a change in behavioral responses.
As we now know, the principles of workbiological systems at different stages of organization of living matter - molecular, cellular, tissue and organogenic - is studied by the science of physiology. What is the metabolism at each of these levels and how it happens - the answers to these questions are given by the applied industries.
Thus, the biochemistry of gas exchange considers physiologycellular respiration, which is the basis for providing the entire human body with oxygen. It enters into oxidation-reduction reactions with organic substances of cells, as a result of which the released energy is accumulated in the form of ATP molecules, which are used by the body for muscle work, growth and development. As we see, physiological processes are an integral characteristic of all biological systems at various stages of their organization.