Parabiosis physiology. Methods of research glands of internal secretion - abstract

07.06.2020

Experimental facts that make up the basis of the study of parabiosis, N.V. The introduced (1901) outlined in his classic work "Architis, braking and anesthesia".

When studying parabiasis, as well as in the study of lability, the experiments were carried out on a neuromuscular drug.

N. E. Vvedensky found that if the nerve section is subjected to alteration (i.e., the effects of the damaging agent) by means of, for example, poisoning or damage, then the lability of such a plot decreases sharply. Restoration of the initial state nerve fiber After each potential of the action in the damaged area, slowly occurs. Under action to this section of frequent stimuli, it is not able to reproduce the specified irritation rhythm, and therefore pulses are blocked.

The neuromuscular drug was placed in a wet chamber, and three pairs of electrodes were imposed on its nerve to apply irritation and disgrace of biopotentials. In addition, in experiments, the abbreviation of the muscle and the nerve potential between intact and alterated sites was recorded. If the plot between the annoying electrodes and the muscle to expose drugs and continue to irritate the nerve, then the answer to irritation after a while suddenly disappears. NOT. Introduced, examining in such conditions of drugs and listening to the phone's biotok phones below the narcotized site, noticed that the rhythm of irritation begins to transform for some time before the muscle response completely disappears. Such a state of reduced lability was named by N. E. Introduced Parabites. In the development of the state of parabiasis, you can mark three, sequentially replacing each other, phases:

Equability

Paradoxical I.

Brake

which are characterized by varying degrees of excitability and conductivity when applied to the nerve of weak (rare), moderate and strong (frequent) irritations.

If a narcotic substance It continues to act after the development of the brake phase, then irreversible changes can occur in the nerve, and it dies.

If the drug action is discontinued, then the nerve slowly restores its initial excitability and conductivity, and the recovery process passes through the development of the paradoxical phase

In the state of parabiasis there is a decrease in excitability and lability.

The doctrine of N.E.Vedhensky on parabitads is universal, because Reacting patterns identified in the study of the neuromuscular drug are inherent in an integer organism. Parabitosis There is a form of adaptive reactions of living formations on a variety of impacts and the doctrine of parabitamia is widely used to explain the various response mechanisms not only cells, tissues, organs, but also a whole body.

Optional: Parabites - means "Near Life". It occurs under action on the nerves of parabiotic stimuli (ammonia, acid, fat solvents, KCl, etc.), this stimulus changes lability, reduces it. And reduces its phase, gradually.

Parabiosis phases:

1. First, the equalization phase of parabiasis is observed. Usually a strong stimulus gives a strong answer, and the smaller is smaller. Here there are equally weak answers to various stimuli (demonstration of the schedule).

2. The second phase is the paradoxical phase of parabitease. A strong stimulus gives a weak answer, a weak - strong answer.

3. Third phase - parase phase paraza. And there is no answer to the weak and strong irritant. This is due to the change in lability.

The first and second phase is reversible, i.e. With the termination of the parabiotic agent, the fabric is restored to a normal state, to the initial level.

The third phase is not reversible, the brake phase passes through a short period of time into the death of the fabric.

The mechanisms of parabiotic phases

1. The development of parabiasis is due to the fact that under the action of the damaging factor there is a decrease in lability, functional mobility. This is the basis of responses that are called parabiosis phases.

2. In normal condition, the fabric obeys the law of irritation force. The greater the power of irritation, the greater the answer. There is an irritant that causes the maximum answer. And this value is indicated as the optimum frequency and force of irritation.

If this frequency or the power of the stimulus exceeds, the response is reduced. This phenomenon is pessimum frequency or irritation force.

3. The value of the optimum coincides with the magnitude of lability. Because Labeliness is the maximum ability of the fabric, the maximum possible tissue response. If the lability changes, then the values \u200b\u200bin which instead of optimum develops pessimum, shifted. If you change the lability of the tissue, then the frequency that caused the optimum response will now cause pessimum.

Biological value of parabiasis

The discovery of the introduction of parabiosis on a neuromuscular drug in the laboratory has been colossal effects for medicine:

1. It showed that the phenomenon of death is not instantaneously, there is a transitional period between life and death.

2. This transition is carried out by Phazno.

3. The first and second phases are reversible, and the third is not reversible.

These discoveries led in medicine to the concepts - clinical death, biological death.

Clinical death is a reversible state.

Biological death - irreversible condition.

As soon as the concept of "clinical death" was formed, a new science appeared - resuscitation ("RE" - a return pretext, "Anima" - life).

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This topic belongs to the section:

Physiology

General physiology. The physiological basis of behavior. Higher nervous activity. The physiological foundations of human mental functions. Physiology of targeted activities. The adaptation of the body to various conditions of existence. Physiological cybernetics. Private physiology. Blood, lymph, fabric liquid. Circulation. Breath. Digestion. Metabolism and energy. Food. Central nervous system. Methods for researching physiological functions. Physiology and biophysics of excitable tissues.

This material includes sections:

The role of physiology in a dialectic and materialistic understanding of the essence of life. Communication of physiology with other sciences

The main stages of physiology

Analytical and systematic approach to the study of the functions of the body

The role of I.M. Suchenova and I.P. Pavlova in creating the materialistic foundations of physiology

Protective systems of the body that ensure the integrity of its cells and tissues

General properties of excitable fabrics

Modern ideas about the structure and functions of membranes. Active and passive transport of substances through membranes

Electrical phenomena in excitable fabrics. History of their opening

The potential of action and its phase. Changing the permeability of potassium, sodium and calcium channels in the process of forming the action potential

Membrane potential, its origin

The ratio of the phases of excitability with phases of the potential of action and solitary reduction

Laws of irritation of excitable tissues

DC Action on Live Fabrics

The physiological properties of the skeletal muscle

Types and modes of reduction of skeletal muscles. Single muscular abbreviation and its phase

Tetanus and its types. Optimum and pessimum irritation

Labeliness, parabital and its phase (N.E.Vedensky)

The strength and work of the muscles. Dynamometry. Ergography. The law of average loads

Distribution of excitation by shaggy nerve fibers

Building, classification and functional properties of synapses. Features of transferring excitation in them

Functional properties of ferrous cells

The main forms of integration and regulation of physiological functions (mechanical, humoral, nervous)

System organization of functions. I.P. Pavlov - the founder of the system approach in understanding the functions of the body

The doctrine of P.K.Anokhin on functional systems and self-regulation of functions. Nodal functional system mechanisms

The concept of homeostasis and homeokine. Self-regulatory principles for maintaining the constancy of the internal environment of the body

Reflexary Regulation Principle (R. Dekart, G.Prokhazka), its development in the works of I.M. Schechenova, I.P. Pavlova, PK Zanokhina

Basic principles and features of the spread of initiation in the central nervous system

Braking in the central nervous system (I.M.Sethenov), its types and role. Modern view of central braking mechanisms

Principles of coordination activities of the central nervous system. General principles of coordination activities of the central nervous system

Autonomous and somatic nervous systems, their anatomy-fuchanation differences

Comparative characteristics of the sympathetic and parasympathetic departments of the vegetative nervous system

Congenital form of behavior (unconditional reflexes and instincts), their meaning for adaptive activities

Conditional reflex as a form of adaptation of animals and a person to changing the conditions of existence. Patterns of education and manifestation of conditional reflexes; Classification of conditional reflexes

Physiological mechanisms for formation of reflexes. Their structural and functional basis. Development of ideas I.P.Pavlova on the mechanisms of formation of temporary ties

Brake phenomenon in GNI. Types of braking. Modern view of braking mechanisms

Analytics and synthetic activities of the cortex of large hemispheres

Architecture of a holistic behavioral act from the point of view of the theory of the functional system PK Zanokhina

Motivation. Classification of motivations, the mechanism of their occurrence

Memory, its value in the formation of holistic adaptive reactions

The teaching of I.P.Pavlova about the types of GNI, their classification and characteristics

Biological role of emotions. Theories of emotions. Vegetative and somatic components of emotions

Physiological mechanisms of sleep. Sleep phases. Sleep theory

The teaching of I.P.Pavlova about I and II signaling systems

The role of emotions in targeted human activity. Emotional stress (emotional stress) and its role in the formation of psychosomatic diseases of the body

The role of social and biological motivations in the formation of targeted human activity

Features of changes in vegetative and somatic functions in the body related to physical labor and sports activities. Physical training, its impact on human performance

Features of human labor activities in the context of modern production. Physiological characteristic of labor with neuro-emotional and mental tension

Adaptation of the body to physical, biological and social factors. Types of adaptation. Features of the adaptation of a person to the action of extreme factors

Physiological cybernetics. The main tasks of modeling physiological functions. Cybernetic study of physiological functions

The concept of blood of its properties and functions

The electrolyte composition of blood plasma. Osmotic blood pressure. Functional system ensuring the constancy of osmotic blood pressure

Functional system supporting the constancy of acid-alkaline equilibrium

Characteristics of blood shaped elements (red blood cells, leukocytes, platelets), their role in the body

Gumoral and nervous regulation of erythro and leukopoiesis

The concept of hemostasis. The process of blood coagulation and its phase. Factors accelerating and slowing blood coagulation

Blood groups. Resh factor. Blood transfusion

Fissure liquid, liquid, lymph, their composition, quantity. Functional value

The value of blood circulation for the body. Circulation as a component of various functional systems defining homeostasis

Heart, his hemodynamic function. Change in pressure and blood volume in the cavities of the heart into various phases of the cardiocycle. Systolic and minute blood volume

Physiological properties and features of cardiac muscle tissue. Contemporary idea of \u200b\u200bthe substrate, nature and gradient of the heart

Heart tones and their origin

Self-regulation of heart activities. Heart Law (Starling E.H.) and modern additions to it

Gumoral regulation of heart activities

Reflex regulation of heart activity. Characteristics of the effect of parasympathetic and sympathetic nerve fibers and their mediators on the activity of the heart. Reflexogenic fields and their meaning in the regulation of heart activities

Blood pressure, factors resulting in the size of arterial and venous blood pressure

Arterial and bulbs, their origin. Analysis of the Sphigmogram and Phlebogram

Capillary blood flow and its features. Microcirculation and its role in the mechanism of fluid exchange and various substances between blood and tissues

Lymph system. Limph formation, its mechanisms. Lymphal function and lymph formation and lymphotok regulation features

Functional features of the structure, functions and regulation of vessels of the lungs, hearts and other organs

Reflex regulation of vessel tone. Vasomotor center, its efferent influences. Afferent influences on the vasomotor center

Gumoral influences on vascular tone

Blood pressure - as one of the physiological constants of the body. Analysis of the peripheral and central components of the functional system of blood pressure self-regulation

Breath, its main stages. The mechanism of external breathing. Biomechanism inhale and exhalation

Gas exchange in the lungs. Partial pressure of gases (O2, CO2) in alveolar air and blood voltage

Transport oxygen blood. The dissociation curve of oxymemoglobin, its characteristic. Oxygen blood capacity

Respiratory center (N.A. Mislavsky). Modern idea of \u200b\u200bits structure and localization. Awritation of the respiratory center

Reflex self-regulation of breathing. Replacement phase change mechanism

Humoral respiratory regulation. The role of carbon dioxide. Mechanism of the first breath of a newborn baby

Breathing in conditions of increased and reduced barometric pressure and when changing the gas environment

Functional system ensuring the constancy of the blood pressure constant. Analysis of its central and peripheral components

Food motivation. Physiological bases of hunger and saturation

Digestion, its meaning. Functions of the digestive tract. Types of digestion depending on the origin and localization of hydrolysis

Principles of regulation of the digestive system. The role of reflex, humoral and local regulation mechanisms. Hormones of the gastrointestinal tract, their classification

Digestion in the oral cavity. Self-regulation of chewing act. The composition and physiological role of saliva. Salivation, its regulation

Digestion in the stomach. The composition and properties of the gastric juice. Regulation of gastric secretion. Phases of the gastric juice

Types of reduction of the stomach. Neurohumoral regulation of stomach movements

Digestion in the 12thistanchine. Surrounding activity of the pancreas. The composition and properties of the pancreas juice. Regulation and adaptive nature of pancreatic secretion to types of food and food rations

The role of liver in digestion. Regulation of the formation of bile, highlighting it in the 12thist

The composition and properties of intestinal juice. Regulation of the secretion of intestinal juice

Lucky and membrane hydrolysis of food substances in various departments of the small intestine. Motor activity of the small intestine and its regulation

Features of digestion in the colon

Suction of substances in various departments of the digestive tract. Types and mechanism of suction of substances through biological membranes

Plastic and energy role of carbohydrates, fats and proteins ...

Main exchange, the value of its definition for the clinic

Energy balance of the body. Work exchange. Energy costs of the body in various types of labor

Physiological Norms Depending on the age, type of labor and body condition

Constancy of the temperature of the internal environment of the body as a necessary condition for the normal flow of metabolic processes. Functional system ensuring maintenance of constancy temperature of the internal environment of the body

Temperature of the human body and its daily oscillations. Temperature of various sections of skin and internal organs

Heat transfer. Ways to recover heat and regulation

Isolation as one of the components of complex functional systems that ensure the constancy of the inner environment of the body. Allocation authorities, their participation in maintaining the most important parameters of the internal environment

Bud. The formation of primary urine. Filter, its number and composition

The formation of finite urine, its composition and properties. Characteristics of the reabsorption process of various substances in the tubules and loop. Secretion and excretion processes in renal tubules

Regulation of kidney activities. The role of nervous and humoral factors

The process of urination, its regulation. Departure of urine

Sevective function of the skin, light and gastrointestinal tract

Education and secretion of hormones, their transport is blood, action on cells and fabrics, metabolism and excretion. Self-regulatory mechanisms of neurohumoral relations and hormone-formational function in the body

Hormones pituitary glands, its functional relationships with hypothalamus and participation in the regulation of the activities of endocrine bodies

Physiology of the thyroid and panic glands

Endocrine pancreatic function and its role in the regulation of metabolism

Physiology of adrenal glands. The role of hormones of the cortex and brainstant in the regulation of the functions of the body

Sex glands. Male and female sex hormones and their physiological role in the formation of sex and regulation of reproduction processes. Endocrine feature of the placenta

The role of the spinal cord in the processes of regulating the activity of the musculoskeletal system and the vegetative functions of the body. Characteristic of spinal animals. Principles of the door of the spinal cord. Clinically important spinal reflexes

Excientable fabrics Professor N. E. Vvedensky, studying the work of a neuromuscular drug when exposed to various stimuli.

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Subtitles

Causes of parabitony

These are a variety of damaging effects on an excitable tissue or a cell that do not lead to rough structural changes, but in one way or another violating its functional state. Such reasons may be mechanical, thermal, chemical and other stimuli.

Parabiosis phenomenon essence

As the introduced itself considered, the parabitony is based on the decrease in excitability and conductivity associated with sodium inactivation. Soviet cytoophysiologist N.A. Petroshin believed that the parabiasis was based on reversible changes in protoplasm proteins. Under the action of a damaging agent cell (tissue), without losing structural integrity, completely stops functioning. This condition develops phase, as the damage to the damaging factor (that is, it depends on the duration and strength of the current stimulus). If the damaging agent does not remove in time, then the biological death of the cell (tissue) comes. If this agent is removed on time, then the fabric is also returned to a normal state.

Experiments N.E. Introduced

Vvedensky conducted experiments on the neuromuscular frog preparation. On the sciatic nerve of the neuromuscular drug, testing irritants of different power were consistently applied. One stimulus was a weak (threshold), that is, caused the minimum largest reduction in the icy muscle. Another stimulus was strong (maximum), that is, the smallest of those that cause the maximum reduction of the icy muscle. Then the damaging agent was applied to the nerve at the nerve and every few minutes of the neuromuscular drug was tested: alternately weak and strong stimuli. At the same time, the following stages were sequentially developed:

Equabilitywhen, in response to a weak stimulus, the magnitude of the abbreviation of the muscle did not change, and in response to a strong amplitude of the muscle contraction, decreased sharply and became the same as when responding to a weak stimulus;
Paradoxicalwhen, in response to a weak stimulus, the magnitude of the abbreviation of the muscle remained the same, and in response to a strong stimulus, the amount of the reduction amplitude became less than in response to a weak stimulus, or the muscle did not decrease at all;
BrakeWhen both the muscles did not respond to a strong and weak stimuli. This is the condition of the fabric and is indicated as parabitamics.

Biological meaning of parabiasis

. For the first time, a similar effect was seen in cocaine, however, due to toxicity and ability to cause a more secure analogues at the moment - lidocaine and tetrakain. One of the followers of the introduced, N.P. The jacks offered to consider the pathological process as parabios stage, therefore, anti-parabiotic means it is necessary to use it.

The concept of O. parabitosis (Para - about, BIOS - life) N. E. introduced into the physiology of the nervous system. In 1901, N. E. introduced "Architis, braking and anesthesia" was published in 1901, in which he, on the basis of his research, suggested the unity of the processes of excitation and braking.

N. E. Vvedensky discovered that excitable fabrics on the most diverse (ether, cocaine, constant current, etc.) extremely strong impact They correspond to a peculiar phase reaction, the same in all cases, which he called parabital.

N. E. Vvedensky studied parabiosis phenomenon on nerves, muscles, glands, spinal cord and concluded that parabitami - this is a common, universal reaction excitable tissues on a strong or prolonged impact.

The essence of parabiasis is that under the influence of an irritant in excitable tissues, their physiological properties change, first of all lability is sharply reduced.

The classic experiments N. E. The Parabiasis introduced on the study of parabiasis were performed on a neuromuscular frog preparation. The nerve on a small area was damaged (alteration) chemicals (cocaine, chloroform, phenol, potassium chloride), severe pharadic current, mechanical factor. Then they applied irritation by electric shock to an allyed nerve section or above it. Thus, the impulses should have been either occurring in an alterated nerve segment, or pass through it on their way to the muscle. The abbreviation of the muscle testified to the initiation of nerve. The scheme of the experience of N. E. Vvedensky is presented in Fig. 62.

Fig. 62. Scheme of the experience of N. E. Vvedensky under the study of parabitinis. A - electrodes for irritation of a normal (intact) section of the nerve; B - electrodes for irritation of the "parabiotic section of the nerve"; B - discharge electrodes; D - phone; To 1, to 2, to 3 - telegraph keys; S 1, S 2 and P 1, P 2 - primary and secondary windings of induction coils; M - Muscle

The development of parabiance proceeds in three stages: patch, paradoxical and braking.

The first stage of parabiasis - pharmacy, equalizing, or transformation stage. This parabiosity stage is preceded by the rest, hence its name - piercing. It is called it because during this period of development of the parabiotic state of the muscle corresponds to the same abbreviations on strong and weak irritations applied to the nerve area located above the an alterated. In the first parabiosis stage, there is a transformation (alteration, translation) of frequent excitation rhythms into more rare. All described changes in the muscle response and the nature of the appearance of the excitation waves in the nerve under the influence of irritation are the result of the weakening of the functional properties, especially lability, in an anteidated area of \u200b\u200bthe nerve.

The second stage of parabitease - paradoxical. This stage occurs as a result of continuing and deepening changes in the functional properties of the parabiotic segment of the nerve. A peculiarity of this stage is the paradoxically ratio of an alterated area of \u200b\u200bthe nerve to weak (rare) or strong (frequent) excitation waves coming here from normal areas of the nerve. Rare excitation waves pass through the parabiotic segment of the nerve and determine the abbreviation of the muscle. The frequent waves of excitation are not at all carried out, as if they fade here, which is observed with the full development of this stage, or cause the same contractual effect of the muscle, as well as rare excitation waves, or less pronounced (Fig. 63).

Third Parabiosis Stage - Brake. Characteristic feature This stage is that in the parabiotic section of the nerve, excitability and lability are not only sharply reduced, but it also loses the ability to carry out the muscle and weak (rare) waves of excitation.

Parabites - reversible phenomenon. When eliminating the cause that caused parabitals, the physiological properties of the nerve fiber are restored. At the same time, the inverse development of parabiasis phases is observed - braking, paradoxical, equalizing.

The presence of electronegability in an alterated area of \u200b\u200bthe nerve allowed N. E. Vvedensky to consider parabitals as a special type of arousal, localized at the site of its occurrence and not capable of spreading.

Parabiosis - Means "Near Life". It occurs when actions on the nerves parabiotic stimuli (ammonia, acid, fat solvent, KCL, etc.), this stimulus changes lability , reduces it. And reduces its phase, gradually.

^ Parabiosis phases:

1. First observed equalizing phase Parabecia. Usually a strong stimulus gives a strong answer, and the smaller is smaller. Here there are equally weak answers to various stimuli (demonstration of the schedule).

2. The second phase - paradoxical phase Parabecia. A strong stimulus gives a weak answer, a weak - strong answer.

3. Third Phase - brake phase Parabecia. And there is no answer to the weak and strong irritant. This is due to the change in lability.

The first and second phase - reversible . With the termination of the parabiotic agent, the fabric is restored to a normal state, to the initial level.

The third phase is not reversible, the brake phase passes through a short period of time into the death of the fabric.

^ The mechanisms of parabiotic phases

1. The development of parabiasis is due to the fact that under the action of the damaging factor occurs reduction of lability, functional mobility . This is the basis of answers that call parabiosis phases .

If this frequency or the power of the stimulus exceeds, the response is reduced. This phenomenon is pessimum frequency or irritation force.

Biological Parabiosis

The discovery of the injected parabiosis on a neuromuscular drug in the laboratory had colossal consequences for medicine:

1. showed that death phenomenon not instantly , There is a transition period between life and death.

2. This transition is carried out phazno .

3. The first and second phases reversible , and the third not reversible .

These discoveries led in medicine to the concepts - clinical death, biological death.

Clinical death - This is a reversible condition.

^ Biological death - irreversible condition.

As soon as the concept of "clinical death" was formed, a new science appeared - resuscitation ("Re" - a return pretext, "Anima" - life).

^ 9. DC effect ...

Permanent current on the fabric has Two types of action:

1. Exciting action

2. Electrotonic action.

The excitation effect is formulated in three porugger laws:

1. Under the action of a direct current on the fabric, the excitation occurs only at the time of circuit of the chain or at the time of opening the chain, or with a sharp change in the current force.

2. Excitation occurs when closed under the cathode, and when opening - under the anode.

3. The cathodezacing threshold is less than the threshold of annexicing effect.

We will analyze these laws:

1. The excitation occurs during closure and opening or with a strong current of the current, because it is these processes that create the necessary conditions for the occurrence of depolarization of membranes under the electrodes.

2. ^ Under the cathode, closure chain, we substantially enter the powerful negative charge on the outer surface of the membrane. This leads to the development of the depolarization process of the membrane under the cathode.

Therefore, it is precisely under the cathode that the process of excitation during closure occurs.

Consider a cage under the anode. When the circuit is closed, there is a powerful positive charge on the surface of the membrane, which leads to membrane hyperpolarization. Therefore, under the anode there is no excitement. Under the action of current develops accommodation. Kud. shifted Following the potential of the membrane, but to a lesser extent. Ecavitability is reduced. No conditions for excitement

We open the chain - the potential of the membrane will quickly return to the initial level.

^ Kudok quickly cannot change, it will return gradually and rapidly changing the potential of the membrane will reach Kud -there will be an arousal . In thatmain reason thatexcitation arisesat the moment of opening.

At the moment of opening under the cathode ^ Kud slowly returns to the initial level, and the membrane potential does it quickly.

1. Under the cathode, with a long-term action of the DC, the phenomenon will appear on the fabric - catalog depression.

2. Under the anode at the time of the closure there will be an anode block.

The main feature of the catalog depression and the anode block is Reducing excitability and conductivity to zero level.However, the biological tissue remains alive.

^ Electrootonic action of direct current on fabric.

Under an electrotonic action, the action of direct current on the fabric is understood, which leads to a change in the physical and physiological properties of the tissue. In connection with these distinguishes two types of electrotroid:

Physical electrotone.
Physiological electrotone.

Under the physical electrotone, the change in the physical properties of the membrane, which occurs under the action of DC - change permeability Membranes, critical level of depolarization.

Under physiological electrotone, the change in the physiological properties of the tissue is understood. Namely - empathy, conductivity Under the action of electric flow.

In addition, the electrotone is divided into the analchoton and the canoecotrotone.

Annechoton - changes in the physical and physiological properties of tissues under the action of the anode.

Caekelectron - changes in the physical and physiological properties of tissues under the action of the cathode.

The permeability of the membrane will change and this will be expressed in the hyperpolarization of the membrane and under the action of the anode will be gradually decreased by KUD.

In addition, under the anode under the action of constant electric current develops physiological component of electrotroid. So under the action of the anode varies excitability. How does the excitability change under the action of the anode? Included electric strokes - Kud shifts down, the membrane hyperpolarized, the level of rest potential was dramatically shifted.

The difference Majda Kudud and the rest potential increases at the beginning of the electrical current under the anode. So excitability under the anode at the beginning will decline. The membrane potential will slowly shift down, and Kud is strong enough. This will lead to the recovery of excitability to the initial level, and with a long-term action of the DC under the anode, excitability will grow upsince the difference between the new level where the membrane potential is less than alone.

^ 10. Building Biommbran ...

The organization of all membranes has a lot in common, they are built in the same principle. The basis of the membrane is a lipid bilayer (double layer of amphiphilic lipids) that have a hydrophilic "head" and two hydrophobic "tail". In the lipid layer, lipid molecules are spatially oriented, addressed to each other with hydrophobic "tails", the heads of molecules are facing the outer and inner surface of the membrane.

^ Membrane lipids: phospholipids, sphingolipids, glycolipids, cholesterol.

Perform, in addition to the formation of the bilipid layer, other functions:

form an environment for membrane proteins (altowork activators of a number of membrane enzymes);
are predecessors of some second intermediaries;
Perform an "anchor" function for some peripheral proteins.

Among membranes belkov Allocate:

peripheral - located on the outer or inner surfaces of the bilipid layer; On the outer surface, they include receptor proteins, adhesion proteins; On the inner surface - system proteins secondary intermediaries, enzymes;

integral - Partially immersed in the lipid layer. These include receptor proteins, adhesion proteins;

transmembrane - permeate the whole membrane turn, and some proteins pass through the membrane once, and others - repeatedly. This type of membrane proteins generates pores, ion channels and pumps, carrier proteins, receptor proteins. Transmembrane proteins play a leading role in the interaction of the environment with the environment, providing a signal reception, carrying it into a cell, gain at all distribution stages.

In the membrane, this type of protein forms domains (Subunits), which provide transmembrane proteins of essential functions by transmembrane proteins.

The domain base is the transmembrane segments formed by non-polar amino acid residues shrewd in the form of OS-helix and emembrane loops representing the polar areas of proteins, which can be quite far beyond the bilipid layer of the membrane (denoted as intracellular, extracellular segments), separately seen and NN 2 -Terminal domains.

Often simply allocate transmembrane, out and intracellular parts of the domain - subunit. Membrane proteins also divide on:

Structural proteins: Press the membrane form, a number of mechanical properties (elasticity, etc.);
Transport proteins:

Form transport streams (ion channels and pumps, carriers proteins);
Protect the creation of transmembrane potential.

Proteins providing intercellular interactions:

Adhesive proteins, bind cells with each other or with extracellular structures;

protein structures involved in the formation of specialized intercellular contacts (desplaomomomy, nexus, etc.);
Proteins directly participating in the transmission of signals from one cell to another.

The membrane includes carbohydrates in the form of glycolipid and glycoprotein. They form oligosaccharide chains, which are located on the outer surface of the membrane.

^ Membrane properties:

1. Self-assembly in aqueous solution.

2. Circuit (self-seating, closedness). The lipid layer always closes itself to the formation of fully delimited compartments. This provides self-access during the membrane damage.

3. Asymmetry (transverse) - the outer and inner layers of the membrane differ in composition.

4. Liquidity (mobility) of the membrane. Lipids and proteins can be moved in their layer under certain conditions:

lateral mobility;

rotation;
bending,

And also go to another layer:

Vertical movements (flip flops)

5. Semipermeability (selective permeability, selectivity) for specific substances.

^ Membrane functions

Each of the membranes in the cell plays its biological role.

Cytoplasmic membrane:

Rewards the cell from the environment;

Carries out the regulation of metabolism between the cell and the microenvironment (transmembrane exchange);

Recognition and reception of irritants;

Takes part in the formation of intercellular contacts;

Ensures the attachment of cells to the extracellular matrix;

Generates electrosenesis.

Date added: 2015-02-02 | Views: 3624 |

Parabitosis (in Per .: "Para" - about, "bio" - life) - this is a condition on the verge of life and the fabric gibbles occurring when exposed to it toxic substances such as drugs, phenol, formalin, various alcohols, alkalis and others, as well as the lengthy effect of the electric current. The doctrine of parabital is associated with the clarification of braking mechanisms, which underlies the body's life activity

As you know, fabrics can be in two functional States - Brakes and excitement. Excitation is the active condition of the tissue, accompanied by the activities of any organ or system. Braking is also an active condition of the tissue, but characterized by the oppression of any organ or system of the body. According to the introduction, one biological process occurs in the body, which has two sides - braking and excitement, which proves the doctrine of parabitosis.

The classical experiments of the introduced in the study of parabitally were carried out on a neuromuscular preparation. At the same time, a pair of electrodes imposed on the nerve was used, between which the mocked KCL was placed (potash parabia). In the development of parabiasis, four phases were detected.

1. The phase of short-term enhancement of excitability. It is rarely captured and lies in the fact that under the action of the sub-step stimulus of the muscle is reduced.

2. Phase equation (transformation). It manifests itself in the fact that the muscle is frequent and rare muscle incentives is equal in the size of the reduction. Alignment of muscle effects is based on the data of the injected, due to the parabiotic area, which reduces the lability under the influence of the CL. So, if the lability in the parabiotic area decreased to 50 im / s, then this frequency he misses, while the more frequent signals are delayed in the parabital area, since part of them falls during the refractoring period, which is created by the previous impulse and In this regard, does not show its action.

3. Paradoxical phase. It is characterized by the fact that under the action of frequent incentives, there is a weak cutting effect of the muscle or is not observed at all. At the same time, the actions of rare impulses take place a slightly greater body reduction in the magnitude than more frequent. The paradoxical muscle reaction is associated with even greater decrease in lability in a parabital area, which almost loses the property of frequent pulses.

4. Brake phase. In this period, the state of the tissue through the parabiotic portion does not pass neither the frequent impulses, as a result of which the muscle H is reduced. Maybe in the parabiotic site the tissue died? If you stop acting kcl, then the neuromus-muscular drug gradually restores its function, passing the parabiament stage in the reverse order, or to act on it with single electrical incentives to which the muscle is slightly reduced.

According to the injected, in the parabiotic area during the braking phase, stationary excitation develops, blocking the excitation to the muscle. It is the result of the excitation amount created by the irritation of the KCL and coming from the place of electrical stimulation by pulses. According to the introduced data, the parabiotic area has all signs of excitation, except for one - the ability to spread. As it should, the brake phase of parabiasis reveals the unity of the processes of excitation and braking.

According to modern data, the decrease in lability in the parabiotic area is apparently due to the gradual development of sodium inactivation and the closing of sodium channels. Moreover, the more often impulses come to it, the fact that it appears to a greater extent. Parabiotic braking is common and occurs in many as physiological, so especially pathological conditions, including the use of various narcotic substances.