Lecture 8 Flashcards
Homeostasis
body’s ability to maintain its internal environment in a state of dynamic equilibrium despite external influences that promote imbalance
begins at a cellular level
if external demands exceed capacity of cells to adapt, can result in permanent disequilibrium
Stress
reactions to stimuli that disrupt homeostasis
includes any factor that causes a change within the body. physiological, psychological, social
Hans Selye
credited with coming up with the term of stress
studied why pts with different diseases had similar symptoms
created the general adaptation system
General Adaptation Syndrome
prolonged stress
- Alarm
- Resistance/adaptation
- Exhaustion
Alarm
fight, flight, freeze
immediate responses mediated by the sympathetic nervous system to ensure survival
Resistance/adaptation
hormonal responses if stressor is not removed
longer-term protection by increasing blood glucose and blood pressure
Exhaustion
body has run out of its reserves
mental, physical, emotional responses are depleted
can lead to organ damage `
SNS activation
FAST reaction. immediate to the stressor
blood vessels constrict or dilate
heart rate increases, force of contraction increases
decreased blood to gut
liver releases glucose
HPA axis
SLOW reaction. hormones are released
hypothalamus: CRF
Pituitary: ACTH
Adrenal cortex: cortisol
Cortisol
almost all cells have cortisol receptors
catabolic hormone
decreases inflammation, suppressing immune responses
increases blood glucose and triglycerides
increases blood pressure
increases wake time and decreases REM
temporarily protects against some stressors
prolonged secretion leads to organ/tissue damage
Stress and disease
there is not a direct cause and effect relationship between chronic stress response and illness/disease
strong correlations between chronic stress and conditions like muscle tension, pain, fatigue, etc
Stress factors
situational
environmental
psychologic
physical
Cushing’s syndrome
due to overproduction of cortisol by adrenal cortex
or due to systemaic pharmacological administration of glucocorticoids
chronic stress does NOT result in cushings syndrome
Stress is only ___ of disease
1 component
it is not usually the primary component
avoid blaming the pt or using stress relief as an easy fix
Stress management
the success of the body’s response in maintaining homeostasis in response to stress
some factors we have control over: physical condition, coping strategies, health improving behaviors
