WHAT IS STRESS? Stress ,like Einstein s theory of relativity, is a scientific concept Stress is a reaction people have when excessive pressure or demands are placedS=P>R upon them, and arises when an individual believes they are unable to cope.
AMBIGUITY IN WORD. Stress is a term that is commonly used today but has become•Biology primarily increasingly difficult toattempts to explain define.major concepts ofstress in a stimulus-response manner.•. It shares, to some extent, common meanings in both thebiological and psychological sciences.
BRIEF HISTORYIn the 1920s and 1930s,the term wasoccasionally being usedin biological andpsychological circles torefer to a mental strain,unwelcome happening,or, more medically, aharmful environmentalagent that could cause
HOMEOSTASIS•Walter Cannon used it in 1926 to refer toexternal factors that disrupted what hecalled homeostasis Environmental factors,internal or external Homeostasis is astimuli, continually concept central to thedisrupt homeostasis. idea of stress.. Factors causing an In biology, mostorganism’s condition to biochemical processeswaver away from strive tohomeostasis can be maintain equilibrium, ainterpreted as stress. steady state that exists
STRESS –MYTHS RELATED TO ITEUSTRESS POSITIVE STRESSDISTRESS NEGETIVE STRESS
EUSTRESS refers to a positive response one has to a stressor, which can depend on ones current feelings of control, desirability, location, andindicators of timing of the stressor.eustress mayincluderespondingto a stressorwith a senseof meaning,hope,or vigor.
DISTRESS Is an aversive statePersistent stress in which a person isthat is not resolved unable to adaptthrough coping or completelyadaptation should to stressors and theirbe known as resulting stress anddistress, and may shows maladaptivelead to anxiety, behaviours.withdrawal, anddepressivebehaviour. the most commonly referred to type of stress, having negative implications.
The Yerkes-Dodsonmodel demonstratesthe optimum balanceof stress with a bellcurve (shown in theimage in the topright). This model issupported by researchdemonstratingemotional-coping andbehavioural-copingstrategies are relatedto changes inperceived stress levelon the Yerkes-DodsonCurve
Acute stress is experienced in response to animmediate perceived threat, either physical,emotional or psychological.During an acute stress response,the autonomic nervous system is activatedand the body experiences increased levelsof cortisol, adrenalin and other hormonesthat produce an increased heart rate,quickened breathing rate, and higher bloodpressure. shunted from the extremities to the Blood is big muscles, preparing the body to fight or run away.
Acute stress that is suffered too frequently iscalled episodic stress.Episodic stress is also typically observed in peoplewith “Type A” personality, which involves beingoverly competitive, aggressive, demanding andsometimes tense and hostile. Because of this, Thesymptoms of episodic stress are found in Type Apersons. These include- Longer periods of intermitted depression, anxietydisorders and emotional distressCeaseless worryingPersistent physical symptoms similar to thosefound in acute stressCoronary heart diseases, or other heart problems
Chronic stress is the total opposite of acutestress; it’s not exciting and thrilling, butdangerous and unhealthy. This type of stress is brought about by long- term exposure to stressorsSerious illnesses like stroke, heart attack, cancer,and psychological problems such as clinicaldepression and post-traumatic disorder canoriginate from chronic stress.
Common physical signs and symptoms of chronic stressare:dry mouthdifficulty in breathingpounding heartstomach acheheadachediaphoresisfrequent urinationtightening of musclesMental signs and symptoms include:sudden irritabilitytensionproblems with concentrationdifficulty in sleepingnarrowed perceptionfrequent feelings of fatigue
Stress can occur in individuals depending on onesown perception to situations.However, basically the prior causes causing stressoverall are as follows- 1) Environmental factors 2) Organization factors 3) Individual factors
Biological backgroundThe central nervous system (brain and spinalcord) plays a crucial role in the body’s stress-related mechanisms.The central nervous system works closely withthe body’s endocrine system to regulate thesemechanisms. The sympathetic nervous system, becomesprimarily active during a stress response,regulating many of thebody’s physiological functions in ways that oughtto make an organism more adaptive to itsenvironment.
Different structures of brain associated with astress response are – HYPOTHALAMUS1. AMYGDALA2.3. HIPPOCAMPUS4.5. LOCUS COERULUS6. RAPHE NUCLEUS7. SPINAL CORD8. PITUITARY GLANDADRENAL GLAND
HYPOTHALAMUS- A small portion of the brainlocated "below the thalamus" and abovethe brainstem. Important functions is to help link together thebody’s nervous and endocrine systems.During a stress response, the hypothalamussecretes various hormones,namely corticotrophin-releasing hormone,which stimulates the body’s pituitary gland andinitiates a heavily regulated stress responsepathway.
AMYGDALA- The amygdala is a small,"almond"-shaped structure located bilaterally,deep within the medial temporal lobes of thebrain and is a part of the brain’s limbic system.Thought to play a role in the processing ofemotions, the amygdala has been implicated inmodulating stress response mechanisms,particularly when feelings of anxiety or fear isinvolved.
HIPPOCAMPUS-The hippocampus is a structure locatedbilaterally, deep within the medial temporallobes of the brain, just lateral to eachamygdala, and is a part of the brain’s limbicsystem. During stress, the hippocampus isparticularly important, in that cognitiveprocesses such as prior memories can havea great influence on enhancing,suppressing, or even independentlygenerating a stress response.
LOCUS COERULUS The locus coeruleus is anarea located in the pons of the brainstem that isthe principal site of the synthesis ofthe neurotransmitter norepinephrine, which playsan important role in the sympathetic nervoussystem’s fight-or-flight response to stress.This area receives input from the hypothalamus,amygdala, and raphe nucleus among otherregions and projects widely across the brain aswell as to the spinal cord.
RAPHE NUCLEUS The raphe nucleus is an arealocated in the pons of the brainstem that isthe principal site of the synthesis ofthe neurotransmitter serotonin, which playsan important role in mood regulation,
The spinal cord plays a critical role intransferring stress response neuralimpulses from the brain to the rest of thebody. The spinal cord communicates withthe rest of the body by innervatingthe peripheral nervous system. Certainnerves that belong to the sympatheticbranch of the central nervous system exitthe spinal cord and stimulate peripheralnerves, which in turn engage the body’smajor organs and muscles in a fight-or-flight manner
Pituitary glandThe pituitary gland is a small organ that islocated at the base of of the brain just under thehypothalamusThis gland releases various hormones that playsignificant roles in regulating homeostasis.During a stress response, the pituitary glandreleases hormones into the blood stream,namely adrenocorticotropic hormone, whichmodulates a heavily regulated stress responsesystem.
Adrenal glandThe adrenal gland is a major organ of theendocrine system that is located directly ontop of the kidneys and is chiefly responsiblefor the synthesis of stress hormones that arereleased into the blood stream during astress response. Cortisol is the major stresshormone released by the adrenal gland.
Corticotropin-releasing hormone Cortico tropin-releasinghormone is the neurohormone secreted by thehypothalamus during a stressresponse that stimulates theanterior lobe of the pituitarygland by binding to itscorticotropin-releasinghormone-receptors, causingthe anterior pituitary to releaseadreno corticotropic hormone.
Adreno corticotropic hormoneAdrenocorticotropichormone is the hormonesecreted by the anterior lobeof the pituitary gland intothe body’s blood stream thatstimulates the cortex of theadrenal gland by binding toits adrenocorticotropichormone-receptors, causingthe adrenal gland to releasecortisol.
CortisolCortisol is a steroid hormone, belonging to abroader class of steroids called glucocorticoid,produced by the adrenal gland and secretedduring a stress response. Its primary function isto redistribute energy (glucose) to regions of thebody that need it most (i.e., the brain and majormuscles during a fight-or-flight situation). As apart of the body’s fight-or-flight response,cortisol also acts to suppress the body’s immunesystem.Cortisol is synthesized from cholesterol in theadrenal cortex. Its primary function is to increaseblood sugar through gluconeogenesis, suppressthe immune system and aid in fat and proteinmetabolism
Norepinephrine Norepinephrine is a neurotransmitter released from locus coeruleus when stimulated by the hypothalamus during a stress response. Norepinephrine serves as the primary chemical messenger of the central nervous system’s sympathetic branch that prepares the body for fight-or-flight response.
SerotoninSerotonin is a neurotransmitter synthesizedin the raphe nucleus of the pons of thebrainstem and projects to most brain areas. Serotonin is thought to play an importantrole in mood regulation. Stress-inducedserotonin dysfunctions have beenassociated with anxiety, fear, anddepression-like symptoms.
Neuropeptide Y is a protein that is synthesized in the hypothalamus and acts as a chemical messenger in the brain. Traditionally, it has been thought to play an important role in appetite, feeding behavior, and satiety, but more recent findings have implicated Neuropeptide Y in anxiety and stress, specifically, stress resiliency.
The HPA axis is a multi-step biochemicalpathway whereinformation istransmitted from onearea of the body to thenext via chemicalmessengers.This is one way abiochemical pathway canregulate itself, via afeedback mechanism.
When the hypothalamus receives signals fromone of its many inputs (e.g., cerebralcortex, limbic system, visceral organs) aboutconditions that deviate from an idealhomeostatic state (e.g., alarming sensorystimulus, emotionally charged event, energydeficiency), this can be interpreted as theinitiation step of the stress-response cascade.
The hypothalamus is stimulated by itsinputs and then proceeds to secretecorticotropin-releasing hormones.This hormone is transported to its target,the pituitary gland, via the hypophysealportal system(short blood vessels system),to which it binds and causes the pituitarygland to, in turn, secrete its own messenger,adrenocorticotropic hormone, systemicallyinto the body’s blood stream.
When adrenocorticotropic hormone reaches andbinds to its target, the adrenal gland, in turnreleases the final key messenger in the cascade,cortisol. Cortisol, once released, has widespread effects inthe body
During an alarming situation in which athreat is detected and signaled to thehypothalamus from primary sensory andlimbic structures, cortisol is one way thebrain instructs the body to attempt to regainhomeostasis – by redistributing energy(glucose) to areas of the body that need itmost, that is, toward critical organs (theheart, the brain) and away from digestiveand reproductive organs, during a potentiallyharmful situation in an attempt to overcomethe challenge at hand.
After enough cortisol has been secreted to best restorehomeostasis and the body’s stressor is no longer presentor the threat is no longer perceived, the heightened levelsof cortisol in the body’s blood stream eventually circulateto the pituitary gland and hypothalamus to which cortisolcan bind and inhibit, essentially turning off the HPA-axis’stress-response cascade via feedback inhibition. Thisprevents additional cortisol from being released. This isbiologically identified as a normal, healthy stressmechanism in response to a situation or stressor – abiological coping mechanism for a threat to homeostasis.It is when the body’s HPA-axis cannot overcome achallenge and/or is chronically exposed to a threat thatthis system becomes overtaxed and can be harmful to thebody and brain. A second major effect of cortisol
is to suppress the body’s immune system during astressful situation, again, for the purpose ofredistributing metabolic resources primarily to fight-or-flight organs. While not a major risk to the body ifonly for a short period of time, if under chronic stress,the body becomes exceptionally vulnerable to immunesystem attacks. This is a biologically negativeconsequence of an exposure to a severe stressor andcan be interpreted as stress in and of itself – adetrimental inability of biological mechanisms toeffectively adapt to changes in homeostasis.
There have been at least 50symptoms diagonised withrespect to stress.1. Frequent headaches, jawclenching or pain2. Gritting, grinding teeth3. Stuttering or stammering4. Tremors, trembling of lips,hands5. Neck ache, back pain,muscle spasms6. Light headedness, faintness,dizziness7. Ringing in the ears
OTHER STRATERGIES. Healthy lifestyle. -Going for a walk. Calling a good friend. Meditating. Light scented candles. Listen to music. Watch a comedy. Set aside relaxation time. Exercise regularly. Eat healthy diet.