home
about the project
Medical news
For authors
Licensed books on medicine
<< Previous Next >>

The role of IM. Sechenova and I.P. Pavlova in creating modern physiology of the brain

THEM. Sechenov (Fig. 54) was a broad-range physiologist. His research concerned many aspects of physiological science. However, he showed particular interest in the physiology of muscles and nerves.

At the end of St. Petersburg University I.M. Sechenov finally chooses physiology as his specialty and goes to improve abroad. There he works with famous physiologists of that time - I. Muller, E.G. Dubois-Reymond, C. Bernard, K.F.V. Ludwig, G. Helmholtz. Already at the beginning of his scientific activity abroad, I.M. Sechenov is distinguished by the desire for the independence of research, performed in an original and thorough manner.

Upon his return from abroad Sechenov actively develops his scientific activities at the Department of Physiology of the Medical and Surgical Academy in St. Petersburg. At that time, he was particularly interested in the physiology of the nervous system.

In 1862, Sechenov discovered the presence of central inhibition in the brain, proving this in a simple but convincing experiment. The hemisphere was removed from the frog, but the diencephalon (visual tubercles) was left. Placing salt crystals on the visual tubercles, it caused a sharp slowdown in the formation of an arc of the flexion reflex. This discovery brought Sechenov worldwide fame. Soon he publishes his wonderful treatise, “Reflexes of the brain,” in which he shows that psychic phenomena are by nature reflexes of the brain. Mental activity, Sechenov claims, is impossible without external irritations of the senses. All acts of conscious and unconscious life by the mode of origin are reflexes. In daily conscious life, a person cannot refuse to influence him from outside through the senses and from feelings coming from his own body. They support his whole mental life. Thus, Sechenov confirms the position that the content of the human psyche is the material world, reflected in the form of sensations, ideas, concepts.

Merits I.M. Sechenov in front of Russian and world science is huge and undeniable. K.A. Timiryazev called Sechenov the father of Russian physiology, who created the school of Russian physiologists. Among Sechenov's students there were a number of prominent scientists, such as V.V. Pashutin, B.F. Verigo, SV Kravkov, V.Ya. Danilevsky, M.N. Shaternikov. Of particular note is the name of one of Sechenov’s talented students - N.E. Vvedensky, whose studies on the physiology of the nerve

muscle fibers can be called classic. Vvedensky proposed a peculiar concept about the nature of inhibition and created the doctrine of parabiosis.

However, I.M. Sechenov expressed a number of provisions on the strict conditioning of the brain, without relying on any large experimental material. Experimentally, the laws underlying the higher nervous activity were obtained by I.P. Pavlov and his school.

The role of I.P. Pavlova (Fig. 55), one of the largest natural scientists of the late XIX - early XX century., Is truly huge. He managed to create a completely new section in science, and, moreover, one of the most difficult ones - the physiology of the cerebral hemispheres. Prior to Pavlov’s work, the physiology of the brain as a harmonious scientific knowledge system did not exist. The works devoted to the physiology of the brain and nerves were very fragmented.
Pavlov’s greatest merit is that, having created his original method of conditioned reflexes, having studied the physiological mechanisms of cortical activity with his help, he synthesized the entire experience of the past, verified and clarified a number of points with numerous, exceptionally accurate experiments.

Thus, Pavlovian physiology is characterized by the breadth of scientific thought and a comprehensive study of the subject, it is aimed at generalizing the mass of factual material, as a result of which it is mainly synthetic in nature. Previous studies that developed various particular questions of neurophysiology were of an analytical nature and could not rise to the level of a broad generalization of the facts found. What was needed was a brilliant swing of Pavlovian thought in order to bring into the orderly system a mass of extracted, sometimes contradictory facts, obtained as a result of past experience and own experiments, amazing in their perfection, to create a new doctrine of the higher nervous activity of animals and humans.

The doctrine of higher nervous activity associated with the names of I.M. Sechenova and I.P. Pavlova, built on a reflex principle. Reflex refers to the response of the body to environmental stimulation through the nervous system. Recognizing that the existence of organisms is possible only in conjunction with the external environment, Pavlov pointed out that the interaction is carried out using special connections, or reflexes. Reflex, according to Pavlov, is a connection that is established between one or another agent of the external environment with one or another activity of the body, carried out through a system of nerve receptors.

The basis of reflex theory are the following basic principles:

1. The principle of determinism is that each phenomenon has its own reason, a certain impetus, an occasion for its development. Hence, a truly scientific study of a phenomenon should first of all clarify the causes of its origin.

2. The principle of structurality. Arguing that the physiological basis of higher nervous activity is the formation of nerve connections (conditioned reflexes) that reflect the outside world, Pavlov, at the same time, timed the formation of conditioned reflexes to the structures and systems of the brain, which in each nervous act enter into new functional relationships.

3. The principle of analysis and synthesis. The cerebral cortex receives countless irritations of the external world, as well as impulses from the internal environment (internal organs). This makes it necessary to first differentiate the complex of incoming stimuli, which occurs through analysis. At the same time, for the regulation of all processes occurring in the body, for the creation of appropriate forms of adaptation to the external environment, it is necessary to generalize the irritations identified by the analysis, i.e. synthesis. Thus, by analysis, the nervous connection can be divided into large fractions. Synthesis, on the other hand, brings together many bonds into an integrated functional system. Analysis and synthesis are the main physiological mechanism of cortical activity. In his experiments, I.P. Pavlov combined the methods of analysis and synthesis and achieved the depth and comprehensiveness of the study of the subject.
<< Previous Next >>
= Skip to textbook content =

The role of IM. Sechenova and I.P. Pavlova in creating modern physiology of the brain

  1. Brain. Appearance, weight. Brain departments
    The cephalic brain is part of the central nervous system of the vast majority of the chordates, its cephalic end; in vertebrates is located inside the skull. The brain is a symmetrical structure, like most other parts of the body. At birth, his weight is approximately 0.3 kg, while in an adult he is approx. 1.5 kg When examining the brain, attention is primarily attracted by two large hemispheres,
  2. Abstract. Brain circulation and brain response to hypoxia, 2012
    Introduction Brain Blood circulation of the brain Brain hypoxia Conclusion List
  3. The role of reproduction biotechnology in breeding, creating new and improving existing animal breeds, in accelerating the breeding process, increasing its capabilities
    Currently, there are exceptionally favorable prerequisites for the further development of animal breeding biotechnology. Particularly great progress has been made in the development and improvement of artificial insemination and transplantation of embryos. This has opened up great prospects in managing the processes of breeding farm animals: - the use of biotechnology creates
  4. BRAIN TUMORS
    Patients with brain tumors make up about 4% among patients with organic lesions of the nervous system. Tumors of the brain in frequency occupy fifth place among tumors of other locations, giving way to tumors of the stomach, uterus, lungs and esophagus. Brain tumors are found at any age, but there is some predominance in the puberty and at the age of 45-50
  5. Brain injuries
    A brain injury occurs when a head is struck or a penetrating wound occurs in which brain function is impaired. The manifestations of a brain injury can be small, moderate, or severe, depending on the severity of the brain injury. Mild manifestations of trauma can consist of a slight change in consciousness, while severe trauma can result in loss of consciousness and
  6. Brain Shells
    The brain is surrounded by three membranes, which are a continuation of the membranes of the spinal cord (Fig. 117). The dura mater of the brain is simultaneously the periosteum of the inner surface of the bones of the skull, with which it is loosely connected. At the base of the skull, the membrane gives rise to processes that penetrate the crevices and openings of the skull. On the inner surface of the hard shell, several
  7. Brain structure
    The brain consists of two hemispheres, which are separated by a deep groove reaching the corpus callosum. The corpus callosum is a massive layer of nerve fibers that connect both hemispheres of the brain. Each hemisphere of the brain has five lobes: frontal, parietal, occipital, temporal and islet. The surface of the brain is covered with bark,
  8. Brain injuries
    Closed brain injuries include concussion (commotio cerebri), contusion (contusio cerebri), compression of the brain (compressio cerebri), often caused by fractures of the bones of the arch or base of the skull and traumatic intracranial hemorrhages. Concussion Clinically, the symptoms of concussion can be divided into three periods: the first -
  9. CORTEX
    As soon as we got to our feet and took an upright position, the same thing happened with our nervous system. Whereas in other animals, the spinal cord is horizontal and the brain in front, our spinal cord is vertical and the brain is at the top, crowning the whole body. In the process of development of the nervous system, new, and, as we might say, “higher”
  10. Cerebral edema
    The development of cerebral edema is closely related to circulatory disorders (Scheme 6.4). On the one hand, circulatory changes in the brain can be direct causes of edema. Edema can occur with a sharp increase in blood pressure in the cerebral vessels due to a significant increase in total blood pressure (edema is called hypertensive). Cerebral ischemia may also be
  11. Brain Abscess
    A brain abscess is a capsule-limited accumulation of brain detritus, white blood cells, pus, and bacteria. The main causative agents The etiological cause of brain abscess can be bacteria, fungi, protozoa and helminths. Of the bacterial pathogens, the most common are vermin streptococci (S. anginosus, S. constellatus and S. intermedius), which occur in 70% of cases. IN
  12. Cerebral circulation
    Normally, the blood supply to the brain is carried out by two pairs - carotid and vertebral, which widely anastomose between themselves with terminal branches, forming a Velizium circle on the basis of the brain. The clinical manifestations of cerebrovascular insufficiency can be understood by comparing the amount of blood supply to the brain and its effect: normal blood flow for the brain is 55 ml /
  13. Tumors of the brain and spinal cord
    Brain tumors make up 10% of all neoplasms and 4.2% of all diseases of the nervous system. Spinal cord tumors are 6 times less common than brain tumors. Etiology. Among the causes of the development of brain tumors are dysembryogenesis. It plays a role in the development of vascular tumors, malformations, ganglioneuroma. Genetic factor matters in the development of vascular
  14. BRAIN TUMORS
    Brain tumors are observed at any age. In children, they are slightly less common than in adults. In the development of tumors in children, great importance is attached to teratogenic effects that violate the normal differentiation of fetal tissues during the prenatal period. These factors include a variety of harmful chemical and physical agents. A role in the appearance of tumors
  15. BRAIN TUMORS
    Classification. Brain tumors are primary and secondary (metastatic), benign and malignant, single and multiple. The clinic adopted the separation of tumors depending on their location in relation to the substance of the brain. There are extracerebral (extracerebral) tumors and intracerebral (intracerebral) tumors. The main part of brain tumors
  16. Brain injuries
    Closed brain injuries include concussion (commotio cerebri), contusion (contusio cerebri), compression of the brain (compressio cerebri), often caused by fractures of the bones of the arch or base of the skull and traumatic intracranial hemorrhages. A concussion occurs when an object hits the head, when a head hits a solid object, or when
Medical portal "MedguideBook" © 2014-2019
info@medicine-guidebook.com