Stress and General Adaptation Syndrome (GAS)
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Questions and Answers

What is the term used to describe the overall process of adaptive change necessary to maintain survival and well-being?

  • Stressors
  • Allostasis (correct)
  • Stress
  • Homeostasis

    • Which of the following is NOT a physiological state in the General Adaptation Syndrome (GAS)?

  • Recovery Stage (correct)
  • Alarm Stage
  • Resistance Stage
  • Exhaustion Stage

    • What is the term used for agents or conditions that can disrupt homeostasis and initiate allostasis?

  • Allostasis
  • Stressors (correct)
  • Homeostasis
  • Stress

    • Which of the following is the best definition of stress according to the text provided?

    <p>The sum of biological reactions caused by disrupted homeostasis. (A)</p> Signup and view all the answers

    Who is credited with theorizing the General Adaptation Syndrome (GAS)?

    <p>Hans Selye (B)</p> Signup and view all the answers

    Which of the following is NOT a characteristic of allostatic overload?

    <p>It is the collective effect of the allostatic state on the organism. (B)</p> Signup and view all the answers

    According to the information provided, which of the following situations could be considered a risk factor, rather than a stressor?

    <p>Living in a high-crime neighborhood. (D)</p> Signup and view all the answers

    Which of the following is a key difference between the GAS theory and the concept of allostasis?

    <p>GAS theory focuses on the body's physiological reaction to stress while allostasis includes psychological stressors. (D)</p> Signup and view all the answers

    What is the primary mechanism by which allostasis achieves stability?

    <p>Through physiological and behavioral change. (D)</p> Signup and view all the answers

    Based on the information provided, which of the following statements accurately describes the relationship between stressors and allostasis?

    <p>Stressors initiate allostasis, which leads to either adaptation or dysfunction. (D)</p> Signup and view all the answers

    Which of these are examples of situations that would activate the GAS?

    <p>A person who is recovering from a bout of the flu (internal stressor) (A), A person who has just received a promotion at work (positive stressor) (B), A person who has been involved in a car accident (negative stressor) (C), A student facing an exam (negative stressor) (D)</p> Signup and view all the answers

    What is the immediate result of the Hypothalamus activating the SNS?

    <p>Release of catecholamines from the adrenal medulla (A)</p> Signup and view all the answers

    Which of these is not true about the 'hypothalamic-pituitary-adrenal (HPA) axis'?

    <p>It can be deactivated by the pituitary gland once it is activated. (B)</p> Signup and view all the answers

    What is the role of the 'resistance stage' in the General Adaptation Syndrome?

    <p>To help the body return to homeostasis after a stressor. (C)</p> Signup and view all the answers

    If a stressor persists for a long period of time, what might happen to the body's systems?

    <p>The body could experience permanent damage due to the prolonged activation of the GAS. (A)</p> Signup and view all the answers

    What is the main characteristic that differentiates the exhaustion stage from the other stages of the GAS?

    <p>The body's inability to return to homeostasis after the stressor is removed. (B)</p> Signup and view all the answers

    Which of the following is NOT a component of the 'pathologic triad' seen in the exhaustion stage?

    <p>Elevated levels of cortisol (A)</p> Signup and view all the answers

    What is the MAIN outcome of the GAS if homeostasis is not restored?

    <p>Death due to system failure. (C)</p> Signup and view all the answers

    Which neurohormone is released by the adrenal medulla in response to stressors?

    <p>Epinephrine (B)</p> Signup and view all the answers

    Which of the following is NOT a function of norepinephrine?

    <p>Stimulates gluconeogenesis in the liver (B)</p> Signup and view all the answers

    What is the primary function of aldosterone?

    <p>Enhance sodium reabsorption in the kidneys (A)</p> Signup and view all the answers

    How do glucocorticoids support the catecholamines?

    <p>By promoting epinephrine synthesis in the adrenal medulla (C)</p> Signup and view all the answers

    Which of the following hormones is NOT associated with the anterior pituitary gland?

    <p>Epinephrine (C)</p> Signup and view all the answers

    What is the primary effect of cortisol on the body?

    <p>Increased glucose availability (B)</p> Signup and view all the answers

    Which hormone is most closely associated with the "fight or flight" response?

    <p>Epinephrine (A)</p> Signup and view all the answers

    Which of these is NOT a mechanism by which endorphins and enkephalins reduce pain?

    <p>Promoting the release of inflammatory mediators (D)</p> Signup and view all the answers

    Which hormone has a calming effect and is often released during childbirth, lactation, and orgasm?

    <p>Oxytocin (B)</p> Signup and view all the answers

    What is the primary consequence of allostatic overload?

    <p>Deterioration of health and well-being (A)</p> Signup and view all the answers

    Study Notes

    Stress and the General Adaptation Syndrome (GAS)

    • Homeostasis is the balanced state of the body's systems.
    • Allostasis is the process of adapting to maintain survival and well-being when homeostasis is disrupted.
    • Stress is the sum of biological reactions to disruptions in homeostasis.
    • Stressors are agents or conditions that cause stress and disrupt homeostasis, triggering allostatic processes.

    General Adaptation Syndrome (GAS)

    • Hans Selye proposed GAS, a model of the body's response to stress.
    • The GAS model has three stages:
      • Alarm stage
      • Resistance stage
      • Exhaustion stage

    Alarm Stage

    • The "fight-or-flight" response is activated.
    • The hypothalamus senses a stressor (internal or external, physical or emotional).
    • The SNS (sympathetic nervous system) is activated.
    • The adrenal medulla releases catecholamines (epinephrine and norepinephrine).
    • The body prepares for quick action.
    • The hypothalamic-pituitary-adrenal (HPA) axis is activated, with the hypothalamus releasing CRH, which stimulates the anterior pituitary gland to release ACTH.
    • ACTH stimulates the adrenal cortex to release glucocorticoids (especially cortisol).
    • This whole cascade is known as the HPA axis.

    Alarm Stage (continued)

    • Prolonged alarm stage results in permanent damage.
    • SNS, adrenal medulla and cortex function at full force.
    • If the alarm stage continues for extended periods, the body experiences significant damage.

    Resistance Stage

    • The body attempts to return to homeostasis.
    • Levels of SNS activity, catecholamines, and glucocorticoids are normalized.
    • If stressors are adequately addressed, the body returns to a steady state showing signs of adaptation.
    • Increasing resistance to the stressor.

    Exhaustion Stage

    • The body is unable to return to homeostasis.
    • Adaptive energy stores are depleted.
    • The body fails to adapt.
    • Physiological effects of excessive stress become apparent.
    • A "pathologic triad" might occur:
      • Hypertrophy of adrenal glands
      • Atrophy of lymphoid tissues
      • Bleeding GI ulcers
    • Death is possible if homeostasis is not restored.

    Problems with the GAS Theory

    • The GAS theory fails to fully explain that stress is often psychosocial.
    • The concept of allostasis enables inclusion of psychosocial stress-related illness.
    • Allostasis is the process of achieving stability or homeostasis through physiological and/or behavioral changes.
    • Allostatic load is the overall effect of chronic stress on the organism resulting in wear and tear.
    • Allostatic overload occurs when the allostatic load is excessive or ineffectively regulated.

    Stressors

    • Stressors can be internal or external, physical or emotional, biological, chemical, or social.
    • May be low-intensity but cause significant impact over time.
    • Risk factors increase the likelihood of experiencing a stressor.

    Neurohormones of Stress and Adaptation

    • Catecholamines (norepinephrine and epinephrine) are neurotransmitters.
    • Released from the CNS in response to stressors.
    • Norepinephrine constricts blood vessels and maintains blood pressure.
    • Epinephrine increases heart rate, cardiac output, and blood pressure.

    More Neurohormones

    • Adrenocortical steroids (cortisol and aldosterone) help regulate cardiovascular system, fluid volume, and metabolism.
    • Glucocorticoids, like cortisol, have a slower onset but longer lasting effect.
    • Cortisol increases protein synthesis in the liver and stimulates gluconeogenesis. It suppresses immune and inflammatory responses.
    • Glucocorticoids also support catecholamines and control blood pressure and cardiac output.
    • Aldosterone regulates sodium, fluid volume, and blood pressure.

    More Neurohormones

    • Endorphins and enkephalins are peptides that reduce pain.
    • Released in response to stressors, by certain foods, laughter, massage, and acupuncture.
    • Endorphins raise pain thresholds.

    Sex Hormones and Stress

    • Cortisol has a negative effect on the release of estrogen and progesterone leading to possible reproductive issues.
    • Testosterone and other androgens help counter cortisol's catabolic effects.
    • Stress can lower testosterone levels.

    Other Stress Hormones

    • Growth hormone is released in response to physical or psychological stimuli.
    • It increases protein synthesis and fat mobilization, and reduces carbohydrate utilization.
    • Prolactin is also released in response to stress, sexual activity, and breastfeeding.
    • It has similar effects to growth hormone.

    Allostatic Overload Effects

    • Many physiological and psychological problems can result from excessive or chronic stress.

    • Effects vary by affected systems.

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    Stress & the Body's Response PDF

    Description

    Explore the concept of stress and the General Adaptation Syndrome (GAS) proposed by Hans Selye. Understand how the body reacts to stress through the stages of alarm, resistance, and exhaustion. This quiz will test your knowledge on homeostasis, allostasis, and stress responses.

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