HTH Chapter 3.2

explain key stress theories as well as the emotional, mental, and physiological changes that occur during the stress response.

homeostasis

a balanced physiological state in which the body’s system function smoothly, maintaining equilibrium.

adaptive response

the physiological adjustments the body makes in an attempt to restore homeostasis.

crisis mode

physiological response triggered by stress after which the body attempts to return to homeostasis by means of adaptative response.

general adaptation syndrome (GAS)

the pattern followed in the physiological response to stress, consisting of alarm, resistance, and exhaustion phases.

• the body’s internal fight to restore homeostasis when stressed.

• physiology/systems theory

GAS alarm phase

the initial reaction to stress, where the body perceives a threat and prepares for a fight-or-flight response.

• triggers hypothalamus to stimulate adrenals glands to release epinephrine (adrenaline), kicks the body into gear.

• can also trigger long term reaction by trigger adrenocorticotrophic hormone to release cortisol.

• lastly the other parts of body release endorphins. 

autonomic nervous system

the portion of the nervous system that regulates body functions normally outside conscious control, such as heart function and breathing.

• two branches: sympathetic and parasympathetic

sympathetic nervous system

responsible for stress arousal, energizes the body for fight or flight by signaling the release of several key stress hormones.

• epinephrine, norepinephrine, and cortisol.

parasympathetic nervous system

slows systems stimulated by the stress response, counteracts the actions of the sympathetic branch. 

hypothalamus

structure in the brain that functions as the control center of the sympathetic nervous system and determines the overall reaction to stressors.

epinephrine

also called adrenaline, a hormone that stimulates body systems in response to stress.

• kicks the body into gear, causing more

  • blood to be pumped with each beat of the heart.

  • dilates airways in lungs to increase oxygen intake.

  • stimulates the liver to release more glucose.

  • dilates the pupils to improve visual sensitivity.

adrenocorticotropic hormone (ACTH)

a hormone produced by the pituitary gland that stimulates the adrenal glands to release cortisol, which helps the body respond to stress.

cortisol

hormone released by the adrenal gland that makes stored nutrients more readily available to meet energy needs.

endorphins

opioid-like hormones that are manufactured in the human body and contribute to natural feelings of well-being

GAS resistance phase

the body tries to return to homeostasis by resisting the alarm responses.

• special hormones such as oxytocin circulate in an attempt to bring physiological process back to homeostasis. 

• because some stressor still exists, the body does not return to homeostasis, and stays revved up, causing higher metabolic rate in some organ tissues.

GAS exhaustion phase

• the hormones, chemicals, and systems that trigger and maintain stress response are depleted by substances such as oxytocin.

• the body puts on the stress brakes beginning to bring systems into balance. may feel tired or drained as your body returns to normal 

allostatic load

wear and tear on the body caused by prolonged or excessive stress responses. 

chronic stress

stress triggers and response reverberate in the body, keeping the body systems at a heightened arousal state

• leads to allostatic load, exhaustive wear and tear on the body. 

• the adrenal glands continue to release cortisol

  • which remains in bloodstream for long period of time due to slower metabolic responsiveness. 

long term cortisol effects

• reduces immunocompetence

• increase risk of health problems 

  • depression, diabetes, heart arrythmias, cancer, inflammation, CDV, digestive disease, insomnia, weight gain. 

immunocompetence

the ability of the immune system to respond to attack and effectively eliminate pathogens.

transactional model of stress and coping

our reaction to stress is not about the nature of a stressor but the interaction between:

• person’s perception, coping ability, and the environment.

  • history, experiences, beliefs.

• four stages: appraisal, secondary appraisal, coping, post-assessment.

• perceptions are key to your stress response; by changing your perceptions, you can reduce the stress effect.

4 stages transactional model

1. appraisal: size up whether the stressor is a real threat.

2. secondary appraisal: assess whether your actions might reduce the threat with the resources you have.

3. coping: take action to reduce a threat.

4. post-assessment: examine what happened and decide whether you need to take more action.

minority stress perspective

theory that minority stress may be partially explained by disparities and the chronic stress inherent in populations where rejection, alienation, and hostility persist.

• especially true in cases with long history of harassment, maltreatment, discrimination, victimization. 

yerkes-dodson law of arousal

when arousal or stress increases, performance goes up but only to a point, after which performance declines.

men response to stress

more likely to fighting or fleeing.

• more likely to withdraw when highly stressed.

women response to stress

more likely to tend and befriend.

• higher levels of oxytocin (cuddle chemical)

• more likely to form social alliances, be empathic, and seek out friends when stress levels are high.

stress theories

• physiology/system theory: general adaptation syndrome (GAS: alarm, resistance, exhaustion)

• psychological theory: the transactional model of stress and coping.