Among the branches of biology and medicine involved in the study of the human body, physiology occupies a special place. What is a physiological system, by what principles does it function and what is it responsible for - these questions were studied by well-known Russian scientists: I.P. Pavlov, P.K. Anokhin, I.M.Sechenov. In our work, we will consider the stages of the formation and formation of physiology. Next, we will get acquainted with the directions that study the metabolic processes of not only the human body, but also animals and plants. We will also give examples confirming the practical importance of the science of the functions of systems, organs and cells of the human body for the development of medicine and maintaining health.
Physiology history
One of the first researchers to study the characteristics of human metabolism was the founder of medicine - Hippocrates. The English physician Harvey, who lived in the 17th century, established the principles of blood movement through a closed system of blood vessels and opened a large circle of blood circulation. The Italian physicist and natural scientist L. Galvani conducted experiments clarifying the nature of nerve impulses and laid the foundations of neurophysiology. This branch of science was further developed thanks to the works of M. I. Sechenov, V. M. Bekhterev, P. K. 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 of 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 metabolic reactions at the molecular, cellular and tissue levels. Followed by embryology and genetics, studying the functions of reproduction and transmission of hereditary properties. And finally, the most significant is the connection of physiology with anatomy, without which it is impossible to correctly determine the processes occurring in each of the functional systems: nervous, endocrine, circulatory, etc.
Contribution of I.P. Pavlov to the study of digestion
The scientific definition of what physiology can be formulated as follows: it is a science that studies the vital functions of all systems that make up 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 I.P. Pavlov. His fistula overlay technique helped reveal the secrets of the duodenal glands. The 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 organ cavity, was studied. It became clear what the physiology of digestion is.
Thanks to the operations of animals unique in accuracy, the scientist presented a complete clinical picture of the functioning of the salivary glands, liver, and stomach. The production of enzymes by their secretory cells occurs under the influence of excitation of the centers of unconditioned reflexes in the stem part of the brain.
The scientist also discovered the neuro-humoral mechanisms of regulation of digestion, for which in 1904 he was awarded the Nobel Prize. IP Pavlov's research was crucial for answering the question "What is human physiology and what is its role in the system of biological disciplines?"
The practical significance of the works of I. M. Sechenov
The brilliant discoveries of the founder of the doctrine of inhibition 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 research on brain reflexes and determined the presence of a local center of inhibition in the thalamus of the diencephalon. According to the ideas of I.M.Sechenov, the signaling 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 determine what the physiology of a sick body is. It served as the basis for medicine in the issue of the correct diagnosis and the selection of optimal methods of treatment. The teaching of I.M.Sechenov on feedbacks in the reflex activity of the brain was a prerequisite for the creation of the science of cybernetics.
The concept of functional systems
The vital activity of the human body as the most perfect biological system of the open type goes far beyond the scope of reflex reactions. The famous Russian scientist P.K. Anokhin created a theory explaining the maintenance of the constancy of the internal environment using a complex of physiological organs and systems. Their well-coordinated work preserves the level of homeostasis corresponding to a healthy body, and is regulated by complex behavioral acts. The scientist’s research helped answer the question of what is the physiology of higher nervous activity, confirmed by Sechenov’s thoughts on the role of higher centers of the cerebral cortex in providing a choice of attitudes, achieving goals and ways to motivate human activity.
In our body there are functional systems of two levels. The first includes mechanisms that help maintain homeostasis through neurohumoral regulation. They provide normal blood sugar, blood plasma composition, blood pressure, etc. The second system supports the body's life support through interaction with the environment through a change in behavioral reactions.
Internal respiration
As we now know, the principles of the operation of biological systems at different levels of the organization of living matter — molecular, cellular, tissue, and organogenic — are studied by physiology. What is metabolism at each of the listed levels and how does it occur? The answers to these questions are given by applied industries.
So, the biochemistry of gas exchange considers the physiology of cellular respiration, which underlies the provision of the entire human body with oxygen. It enters into redox 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 you can see, physiological processes are an integral characteristic of all biological systems at various stages of their organization.