Chapter 6: Arousal & Stress Flashcards
Arousal
alert
wakefulness
active
sympathetic NS
Underarousal
Poor performance
low affect
motivated to do something
Moderate Arousal
good performance
good affect
Overarousal
performance impaired
unpleasant
motivated to become less aroused
Boredom
Associated with underarousal, unpleasantness
Motivation for change, excitement
Can lead to: irritability, decreased attention, decreased HR, decreased BP, and poor performance over time
Sensation seeking
What occurs, and who is most prevalent in
Increases in Monoamine activity (more aroused during these activities)
Adrenal medulla activations
Risk taking greatest in unaffiliated males (males not in long-term partnerships/no offspring)
Surprise
Sudden elevated rate of arousal (more alert)
Startle reflex
Violation of expectancy
Stereotyped facial expressions (mouth opening, eyes agape, ears perk)
Stress
Psychophysiological consequence of any event that challenges organism’s capacity to cope
Stressor
any stimuli that disrupt organism’s homeostatic state, requiring adjustment/adaptation
Rebound (return to homeostasis)
Parasympathetic NS activation occurs in conjunction with slow sympathetic
NS deactivation
Central ACh release
Exhaustion (extreme stress for weeks)
- Causes
Excessive adrenocortical activity
Depleted NTs
Idiosyncratic weaknesses emerge
Physiological and/or mental illnesses emerge
Causes: Heart failure and stroke, Ulcers, Decreased immunity, Tumor growth, Depression and suicide
Acute Stress Physiology
Sympathetic NS activation
Adrenal catecholamine release (epinephrine and norepinephrine)
Central catecholamine release (dopamine and norepinephrine)
HPA axis activation
(CRF –> ACTH–> Adrenal Cortex –> Cortisol)
Examples of Acute Stressors
Novelty Loss in status Loss of control Cognitive challenge Failure in performance Isolation (in social species) Smaller reward than expected
Chronic Stress Physiology
Prolonged HPA axis activation
Adrenal catecholamine release (epinephrine/NE)
Hypothalamus (CRF/CRH)–>Anterior pituitary (ACTH) –>adrenal cortex (cortisol)
Cortisol will decrease in neg feedback loop
Examples of Chronic Stressors
Severe loss of control
Chronic coping failure
Social subordination
Cortisol (effects)
Liberation of stored energy (glycogen to glucose)
Conversion of amino acids and fatty acids to glucose
Stimulation of appetite
Facilitation of adrenaline release from adrenal glands
Temporary suppression of growth hormone and immunity
Cortisol & Appetite
- stressors
- effects
Stressors:
Females: social stress
Males: achievement-failure
Exposure from young age=oversensitivity & eating
Inhibits leptin –increases fat & sugar consumption
Emotional vs Non-emotional eaters:
Ghrelin increases when stressed –causes hypothalamus to release NPY which increase hunger
Returns to baseline quickly in non-emotional eaters, stays elevated in emotional eaters
CRF
Can have direct anxiogenic effects
ACTH
Normally acts on adrenal cortex, also acts in brain to increase catecholamine activity
Corticosteroids (Periphery)
Increased metabolism
Decreased immune response
Inhibited growth and reproduction
Corticosteroids (Brain)
Bind selectively in limbic system (hypothalamus, amygdala, hippocampus, septum)
Moderate levels can inhibit monoamine oxidase (MAO), which breaks down serotonin, dopamine, and norepinephrine, promoting positive affect
Chronically high levels correlated with depression
Chronic Stress Impacts
Suppression of immunity, growth hormone, & reproduction Reduced central monoamine activity Elevated blood pressure Diminished affect Hippocampal damage (causes memory loss) Weight gain around midsection Shorter life span Increased cardiac death in individual when partner dies
How can stress inhibit reproduction?
Females affected more than males (gestation, nursing)
Inhibition of ovulation, cycling, pregnancy disruption
