Unit 2 Part 2 Flashcards
Thw two key platers in stress response
The hypothalamic pituitary adrenocortical (HPA) axis and the sympathetic adrenomedullary (SAM) system. Also have a mina role in energy mobilization and redistribution
T or F: social defeat is NOT a stressor
F, it is one of the bigeest
Describe control and predictability in terms of Chronic stress
- The terms controllability and predictability are central in the definition of a stressor, however:
- It is not the actual control that counts, but the level of perceived control
- Control and predictability must be considered along a continuum in order for them to have meaning.
3 psychologic patterns related to control
- Organisms prepare physiologically in anticipation of expected events - unpredictable situation should be characterized by the absence of an anticipatory response
- It may be the downward slope of the HPA response (or the recovery to baseline) rather than the peak of the response that dissociates a controllable from an uncontrollable condition
- In the SAM system, plasma adrenaline in particular seems to be associated with uncontrollability
What hormones’ is released in responses to stress in Rats
corticosterone
What did early expieremenst by Schuman reveal
- Early experiments by Schuurman (1981) have showed in male rats that the main difference in the corticosterone response to either winning or losing a social interaction is the speed of recovery of the response
- This also holds for the SAM response as well as blood pressure and heart rate responses during winning and losing
- After losing a fight a male rat has high levels of cortisol due to the fact of not knowing what may be coming next.
in the SAM system what is abundant
, plasma epinephrine in particular seems to be associated with the uncontrollable condition.
T or F: stressors can become non stressors
T, The decline of the HPA response with repeated exposures to the stimulus reflects a higher order adaptive process (medial prefrontal cortex) that exerts an inhibitory influence on emotional responsiveness as observed during extinction of conditioned fear
i.e. what was once a stressor is not a stressor anymore.
what 3 things happen When animals are placed in novel environments there is initially higher glucose and epinephrine levels
- Once they have learned about the environment with repeated exposure:
- Their epinephrine levels decrease and norepinephrine levels increase
- The metabolism shifts from glucose to fatty acids
- The magnitude of the sympathetic response reflects metabolic demand; the corticosterone response is also reduced.
What is regulatory range
species and individuals have a species-specific habitat and an ecological niche within which regulating processes operate adequately without requiring adaptive changes
- e.g. ranges for temperature, food availability, or social instability
What is adaptive capacity
the remaining capacity given environmental constraints and the wear and tear of homeostatic processes
- e.g. cold:
- behavioural responses (putting on a jacket) and expenditure
- physiological response (changes in cardiovascular physiology and metabolism).
- The full adaptive capacity includes mechanisms at the level of the brain, peripheral physiology and behaviour.
does tress reduce adative ca[acity
Yes,
Does a shift in regulatory range cause stress
Yes
What is the new definition of stress as far as unit 3
- a stressor is a stimulus or environmental condition in which the response demands exceed the adaptive capacity of the organism
- Demands that fall within the adaptive capacity belong to the realm of the normal physiology and therefore should not be regarded as stressors.
What is the predictive adaptation hypothesis
the prenatal/neonatal environment determines the regulatory range of an organism.
T or F: Uncontrollable/unpredictable stimuli will either affect the adaptive capacity or shift the regulatory range
T, Only under conditions of a mismatch between demands and adaptive capacity, or if the regulatory range is very narrow or poorly suited to the current environment, may pathology develop.
