Physiology of Stress: I. Nervous System a. CNS (central nervous system)
Physiology 2-Higher-nervous-activity
Transcript of Physiology 2-Higher-nervous-activity
PHYSIOLOGY OF PHYSIOLOGY OF HIGHER NERVOUS HIGHER NERVOUS
ACTIVITYACTIVITY
behaviourbehaviour It’s a complex of movements It’s a complex of movements
enabling interaction with the external enabling interaction with the external environmentenvironment;;
Accompanied by vegetative reactionsAccompanied by vegetative reactions
Lower nervous activityLower nervous activity Regulation of organs &
systems functioning; organs & systems connections
in the body Structure – spinal cord,
medullar & midbrain Reflexes- simple & complex
Higher nervous activityHigher nervous activity Human behavior in the external Human behavior in the external
environmentenvironment Human adjustment to the changed Human adjustment to the changed
conditions of the external conditions of the external environmentenvironment
StructuresStructures – – cortex & sub-cortical cortex & sub-cortical structures, sub-cortical gangliastructures, sub-cortical ganglia
ReflexesReflexes – – the most complexthe most complex
History of the subjectHistory of the subject R.R. DecartDecart (1596-1650) – (1596-1650) – reflex archreflex arch SechenovSechenov (1829-1905) – (1829-1905) – the monographthe monograph
««Reflexes of the BrainReflexes of the Brain» - 1863г» - 1863г
Forms of behaviorForms of behavior InbornInborn – – unconditioned reflexes unconditioned reflexes UCRUCR AcquiredAcquired – –conditioned reflexes conditioned reflexes CRCR
Unconditioned reflexesUnconditioned reflexes Have species specificityHave species specificity Displayed as the body grows (in Displayed as the body grows (in
ontogenesis)ontogenesis) ConstantConstant StereotypicalStereotypical Basis for CR formationBasis for CR formation Adequate stimuli cause themAdequate stimuli cause them Cortex isn’t involvedCortex isn’t involved Enable species representatives and whole Enable species representatives and whole
species survivalspecies survival ( (maintain homeostasismaintain homeostasis))
Unconditioned reflexUnconditioned reflex Is Is species specified reaction of the species specified reaction of the
bodybody, , performed on the basis of performed on the basis of inborn nervous connectionsinborn nervous connections, , ii.е. .е. reflecting phylogeneticreflecting phylogenetic adjustment of adjustment of species to the environment of their species to the environment of their inhabitantinhabitant
Conditioned reflexesConditioned reflexes IndividualIndividual Formed during the individual life timeFormed during the individual life time Can be inhibitedCan be inhibited Can be changed with the changing of Can be changed with the changing of
the external environmentthe external environment Non-adequate stimulusNon-adequate stimulus – – stimulus isn’t stimulus isn’t
specific to the receptorsspecific to the receptors Cortex or higher centers involvment is Cortex or higher centers involvment is
obligatoryobligatory Adjustment to the changing conditionsAdjustment to the changing conditions
Conditioned reflexConditioned reflex Is an Is an individually acquired individually acquired
compensatory reactionscompensatory reactions, , which occur which occur on the basis of temporal connection on the basis of temporal connection in CNS between the centers of in CNS between the centers of conditionedconditioned && unconditionedunconditioned reflexesreflexes
INSTINCTSINSTINCTS It’s integrativeIt’s integrative UCR, a synthesisUCR, a synthesis of of
coordinated movements with coordinated movements with vegetative supplyvegetative supply
Chain characterChain character StereotypicalStereotypical, , stiffly fixed forms of stiffly fixed forms of
behaviorbehavior Maintain homeostasis and enable Maintain homeostasis and enable
species survival regardless of anyspecies survival regardless of any incidental changes in the external incidental changes in the external environmentenvironment
INSTINCTS INSTINCTS CLASSIFICATIONCLASSIFICATION
Reflexes enabling species Reflexes enabling species survivalsurvival
SexualSexual ParentalParental TerritorialTerritorial HierarchicHierarchic ( (leaderleader, , herdherd))
Reflexes enabling individual Reflexes enabling individual survivalsurvival
NutritionalNutritional OrientationOrientation ThermoregulatoryThermoregulatory DefensiveDefensive othersothers
Reflexes enabling trans-Reflexes enabling trans-species interaction species interaction
HostilityHostility FriendshipFriendship OthersOthers
Reflexes of developmentReflexes of development Imitative behaviorImitative behavior Exploratory behaviorExploratory behavior Game instinctGame instinct Instinct of learningInstinct of learning othersothers
Rules for building Rules for building conditioned reflexesconditioned reflexes
1.1. ConditionedConditioned ( (neutralneutral) ) stimulusstimulus && unconditioned stimulationunconditioned stimulation should be should be applied simultaneouslyapplied simultaneously
2.2. Multiply repetitionMultiply repetition3.3. Absence of external irritating factorsAbsence of external irritating factors4.4. Alert cortexAlert cortex5.5. Absence of pathological processesAbsence of pathological processes6.6. The force of conditioned stimulus should The force of conditioned stimulus should
be lower than that of unconditioned one, be lower than that of unconditioned one, but not lower than thresholdbut not lower than threshold
MECHANISM OF MECHANISM OF CONDITIONED REFLEX CONDITIONED REFLEX
FORMATIONFORMATION – – By AsratyanBy Asratyan
Mechanism of temporal connection Mechanism of temporal connection formationformation
STIMULUSSTIMULUS
Unconditioned nutritional reflexUnconditioned nutritional reflexUnconditioned light reflexUnconditioned light reflex
STIMULUSSTIMULUS
Possible mechanisms of Possible mechanisms of temporal connectionstemporal connections
Increase in the number of active Increase in the number of active synapsessynapses
Myelinization of non-myelinized fibersMyelinization of non-myelinized fibers Synaptic facilitationSynaptic facilitation Activation of protein biosynthesisActivation of protein biosynthesis
Conditioned reflex of the first order
Conditioned reflex of the second order
Conditioned reflex of the third order
Inhibition of Inhibition of conditioned reflexesconditioned reflexes
UnconditionedUnconditioned - - externalexternalConditionedConditioned - - internalinternalTransmarginalTransmarginal
Inhibition protects the body from Inhibition protects the body from excessiveexcessive biologically non-biologically non-
grounded reactionsgrounded reactions It’s a complex process of interaction It’s a complex process of interaction
of elementary reactions of of elementary reactions of excitationexcitation ((EPSPEPSP) ) & inhibition& inhibition ( (IPSPIPSP) ) on the on the membranes of the neuronsmembranes of the neurons
UnconditionedUnconditioned ( (externalexternal)) – – occurs due to the stimuli occurs due to the stimuli
arousing new reflex reactionarousing new reflex reaction
Extinguishing inhibitionExtinguishing inhibition – – based on based on orientation reflexorientation reflex ( (any inhibitory any inhibitory factorfactor))
Constant inhibitionConstant inhibition – – any factor of any factor of biological importancebiological importance, , which doesn’t which doesn’t cause adaptationcause adaptation ( (painpain))
Conditioned reflexConditioned reflex External inhibition of CRExternal inhibition of CR
INDIFFERENT irritating factor Of no biological importanceOf no biological importance First causes excitationFirst causes excitation – – orientation orientation
reflexreflex ««What is it?What is it?»» reflex reflex
ConditionedConditioned ((internalinternal)) ExtinctionExtinction Differentiation of conditioned stimuliDifferentiation of conditioned stimuli Conditioned inhibitionConditioned inhibition Delayed conditioned reflexesDelayed conditioned reflexes
ExtinctionExtinction
Develops when conditioned signal Develops when conditioned signal isn’t isn’t reinforced by an unconditioned reinforced by an unconditioned stimulusstimulus
Multiply repetition is requiredMultiply repetition is required On the reestablishment of the On the reestablishment of the
reinforcement the reflex can be reinforcement the reflex can be restoredrestored
Differentiation of conditioned Differentiation of conditioned stimulistimuli
One conditioned signalOne conditioned signal ( (that is that is reinforcedreinforced) ) is chosen out of many is chosen out of many similarsimilar
900900HzHz 10001000HzHz 11001100HZHZ
foodfood
SalivaSaliva secretionsecretion
SalivaSaliva secretionsecretion
SalivaSaliva secretionsecretion
Conditioned inhibitorConditioned inhibitor A type of differentiationA type of differentiationflashflash
foodfood
SalivaSaliva secretionsecretion
SalivaSaliva secretionsecretion
flashflashsoundsound ++
ConditionedConditioned inhibitorinhibitor
Delayed inhibitionDelayed inhibitionCS ---------- CS -------------- CS-------------UCS --------- UCS-------- UCS
-------- ---------- ------------- ----------- c.r. c. r. c.r. CS – conditioned stimulus, UCS – unconditioned
stimulusc.r. – conditioned reaction
Transmarginal inhibitionTransmarginal inhibition Caused byCaused by:: Suprathreshold stimuliSuprathreshold stimuli Weak long-lasting stimuliWeak long-lasting stimuli Overexcitation of CNSOverexcitation of CNS Defense mechanismDefense mechanism
Analysis & synthesis Analysis & synthesis in the cortexin the cortex
AnalysisAnalysis – – differentiation of different differentiation of different signalssignals, , formation of conditioned formation of conditioned inhibitioninhibitionSynthesisSynthesis – – connection, summarizing connection, summarizing excitations,excitations, formation of conditioned formation of conditioned reflexreflex
Dynamic stereotypeDynamic stereotype A system of conditioned reflexes A system of conditioned reflexes
which were formed as conditioned which were formed as conditioned signal place related signal place related , , not signal not signal quality relatedquality related
The basis of habits & professional The basis of habits & professional skills formationskills formation
lightlight soundsound metronomemetronome
15 15 dropsdrops10 10 dropsdrops 25 25 dropsdrops
15 15 dropsdrops 10 10 dropsdrops25 25 dropsdrops
lightlightmetronomemetronome soundsound
Main nervous processes Main nervous processes in the cortex & their in the cortex & their
quantitative evaluationquantitative evaluationExcitation & inhibition are Excitation & inhibition are
complex combinations of post-complex combinations of post-synaptic potentials on the neurons synaptic potentials on the neurons
membranesmembranes
Characteristics of nervous Characteristics of nervous processesprocesses
1. Force – working capacity of cortex neurons, their ability to withstand long-lasting & high intensity stimuli .
2. Balance – interrelation between excitation & inhibition.
3. Flexibility – ability of neurons to go from excitation to inhibition & back .
Evaluation of excitation Evaluation of excitation strengthstrength
1) By the velocity of conditioned reflex formation.
2) By the ability to form conditioned reflexes in response to very strong stimuli.
Evaluation of inhibition Evaluation of inhibition strengthstrength
1) By the velocity of differentiational inhibition formation, by its preciseness ( i.e. ability to define between 100 & 90 Hz).
2) By the increased duration of differentiative stimulus.
BALANCE BETWEEN BALANCE BETWEEN EXCITATION & INHIBITIONEXCITATION & INHIBITION
Can’t be defined in special terms yetCan’t be defined in special terms yet
MOBILITY OF NERVOUS MOBILITY OF NERVOUS PROCESSESPROCESSES:
1) CHANGING OF THE SIGNALING MEANING OF THE STIMULUS.
2) NEW STEREOTYPE FORMATION. 3) DECREASED TIME INTERVAL BETWEEN
POSITIVE & DIFFERENTIATIVE STIMULI.
Type of Higher NERVOUS Type of Higher NERVOUS ACTIVITYACTIVITY
• It’s a combination of inborn & acquired properties of nervous system – genotype + phenotype.
According toAccording toHypocrateHypocrate SanguinicSanguinic PhlegmaticPhlegmatic CholericCholeric MelancholicMelancholic
According to According to PavlovPavlov
LivelyLively ССalmalm БезудержныйБезудержный WeakWeak
4 Main types:
CholericCholericMelancholicMelancholic
PhlegmaticPhlegmaticSanguinicSanguinic
Nervous processesNervous processes
strongstrong weakweak
balancedbalancedNon-balancedNon-balanced
mobilemobilestillstill
Weak Weak melancholicmelancholic
Lively Lively sanguinicsanguinic
Calm Calm phlegmaticphlegmatic
Unrestrained Unrestrained cholericcholeric
1- Strong, Balanced, Flexible – lively - sanguinic
2- Strong, Balanced, inert - сalm - flegmatic3- Strong,unbalanced - unrestrained- choleric
4- weak - melancholic
Signaling systemsSignaling systemsI s.s. – system of conditioned reflexes to certain stimuli ( light, sound , others), is common for animals & people
II s.s. - system of conditioned reflexes to abstract stimulus – a word & its meaning,is characteristic only for people
Characteristics of Characteristics of conditioned reflexes in conditioned reflexes in the I and II signaling the I and II signaling
systemssystems
I and II s.s. are connected, they interact continuously
I s.s.:1. Conditioned reflexes are slowly
formed & changed.2. Reaction delay is little (minutes)3. Motivation to action is mainly
biological.4. Maintain body homeostasis.
II s.s.:1. Conditioned reflexes are quickly
formed & changed.2. Reaction delay is quite long (may be
years)3. Motivation to action is both biological
& social.4. Forms consciousness, abstract
thinking, allows social behaviour of man.
Interaction between I and II s.s. in human’s psychics defines special type of higher nervous activity in humans.
1. Artistic typeArtistic type – prevailing role of I s.s. , i.е. figurative perception ( it’s better once to see than 7 times to hear). Right hemisphere is a dominating one.
2. Intellectual typeIntellectual type – prevailing role of II s.s. – analysis activity. Left hemisphere is a dominating one.
3. Medium typeMedium type – no one signaling system is prevailing