front 1 General Adaption Syndrome | back 1 - Initially one becomes alarmed by a stressor that activates the
hypothalamus and sympathetic nervous system
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Alarm stage
-
Adaption stages
- Exhaustion stages
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| back 2 - (1) the alarm stage or reaction, in which the central nervous
system (CNS) is aroused and the body's defenses are mobilized
-
Stressor triggers the hypothalamic-pituitary-adrenal (HPA)
axis
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Activates the sympathetic nervous system (SNS)
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| back 3
Resistance (adaptation) stage
- resistance or adaptation, during which mobilization
contributes to “fight or flight”
- Begins with the actions of
adrenal hormones
- Cortisol, epinephrine, and
norepinephrine
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| back 4 -
Exhaustion stage (allostatic overload)
Occurs
only if stress continues and adaptation is not
successful - stage of exhaustion, where continuous stress
causes the progressive breakdown of compensatory mechanisms
(acquired adaptations) and homeostasis
- Exhaustion marks the
onset of certain diseases (diseases of adaptation)
- if
stress continues and adaptation is not successful, can cause
impairment of the immune response, heart failure, and kidney
failure,
leading to death. |
front 5 Reactive, Anticipatory, and Conditional Response | back 5
Reactive response
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Involves psychologic stressors
Anticipatory response
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Anticipates a disruption in homeostasis "anticipate
something bad", react to a predator or
experience-dependent memory programs
- occurs when
physiologic responses develop in anticipation of disruption of the
optimal steady-state, also known as
homeostasis
Conditional response
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Associates a stimulus with danger
-
May cause posttraumatic stress disorder (PTSD) or
phobias
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| back 6 -
Is initiated by the central nervous system and the endocrine
system
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Stressor can be a perceived or real threat
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front 7 Effects of Stress: Sympathetic Nervous System | back 7 - Epinephrine and norepinephrine released
- Which binds to
adrenergic receptors on various cells
Causing:
- Blood pressure elevation
- Heart rate and cardiac
contractility increase
- Pupil dilation
- Reduction of
blood flow to skin, guts, and kidneys
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front 8 Cortisol: the Stress Hormone | back 8 - Hypothalamus
- secretes Corticotropin Releasing Factor (CRF)
- Anterior pituitary
- secretes
adrenocorticoid hormone (ACTH)
- Adrenal
Cortex
- secretes glucocorticoid: Cortisol
-
Contributes to the development of metabolic syndrome and the
pathogenesis of obesity
-
Development of diabetes is secondary to cortisol-induced
obesity
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Chronic cortisol excess induces lipogenesis in the abdomen,
trunk, and face, resulting in central obesity
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Alters glucose, fat, and protein metabolism
- Increases
blood glucose levels by promoting gluconeogenesis and
glycogenolysis.
- Suppresses inflammatory and immune
responses
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front 9 Cortisol in the Immune System | back 9 - Systemic responses to stress may cause a decrease in innate
immunity and enhance adaptive immunity
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Local responses to stress, under certain conditions, can induce
proinflammatory activities
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Many immune-related conditions and diseases are associated with
stress
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Stress and negative emotions increase levels of proinflammatory
cytokines, providing a possible link among stress, immune
function, and disease
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