stress Flashcards
What is stress?
-a state of threatened homeostasis
stressor
a thing responsible for imbalance
stress-response
the body’s response to the imbalance
What releases Corticotropin Releasing Hormone?
The hypothalamus
where does CRH travel to?
It travels to the pituitary
What is the process of releasing cortisol?
CRH comes from the hypothalamus, goes to the pituitary, then the pituitary releases ACTH which goes to the adrenal gland, and then the adrenal gland releases cortisol
What makes cortisol?
The adrenal cortex
What are glucocorticoids?
glucocorticoids refers to both cortisol and corticosterone
-cortisol is in domestic mammals and corticosterone is in rodents
How do you turn off making cortisol?
negative feedback (AC example)
- 3 WAYS
- to turn off, cortisol can inhibit the pituitary, hypothalamus, or it can stimulate the hippocampus which signals the hypothalamus to stop the cortisol process
When glucocorticiod levels are low…
mineralocorticoid receptors are activated
glucocorticoid receptors mediate…
negative feedback
when glucocorticoid levels are high…
glucocorticoid levels are activated
what do neurons from the spinal cord release?
norepinephrine
- this increases your heart rate, respiration, and blood pressure
what does the adrenal medulla release?
epinephrine
- increase blood glucose levels
What are stress hormones doing?
They are preparing your body to make as much energy available for immediate use as possible
- they do not make you feel stressed!!
Acute stress
- short term stress
- the release of glucocorticoids results in the release of energy (mostly sugar from liver)
chronic stress
- long term
- activation of glococorticoids results in break-down of lipids and protein
- this depletes energy reserves and induces fatigue
in the sympathetic nervous system, acute stress does what?
it inhibits digestion
in the SNS, chronic stress does what?
reduces energy intake and can lead to ulcers
allostasis
- process of how the body responds to daily events and maintains homeostasis
- “achieving stability through change”
in allostasis, what is being use to mobilize and maintain homeostasis?
energy
allostatic load
refers to wear and tear that results from too much stress or from inefficient management of allostasis
When a stressor occurs, what happens? (allostasis)
There is a rapid onset after the stressor exposure and rapid recovery after stressor ends (strong negative feedback)
adaptation (allostasis)
reducing physiological response over time from a stressor
weak negative feedback (allostasis)
having a rapid onset and no recovering
3 types of allostatic loads
- having a stressor that always creates a hit (the lion)
- exposed to a stressor that isn’t really a threat but still generates a hit (bird and dog)
- weak negative feedback
what is the difference between allostasis and homeostasis?
allostasis is making changes to keep things the same and homeostasis is trying to balance your body
-allostasis leads to homeostasis
What was the outcome of the caregiving test?
women were given a wound and it was shown that women who act as caregivers took longer to heal the wound than other women
3 step process to wound healing
- inflammation
- tissue formation
- tissue remodeling
What must be reduced for tissue formation and remodeling to happen?
inflammation
inflammation
immune molecules are recruited to wound site to prevent pathogens from entering the body
tissue formation
wound area closes and forms a scab
tissue remodeling
new stin or scar tissue is produced to permanently close wounds
What did the caregivers have more of?
inflammation markers
- caregiving is increasing inflammation
when do cortisol levels peak?
before waking around 4-5 AM
-they decrease throughout the day
What is dexamethesone?
it exerts negative feedback so the body does not release cortisol and DEX is in the body acting like cortisol instead
What happens when you inject dexamethesone in a control? (depression test)
the body thinks there is plenty of cortisol so it doesn’t make any
-it depresses cortisol for 24 hours
in patients with depression, what is going on with their cortisol?
There is no rhythm in cortisol and they have higher cortisol during sleeping
What is less effective in depressed people?
DEX, it isn’t stopping cortisol
resilience
a person’s ability to adapt successfully to acute stress, trauma, or more chronic forms of adversity
what is stress like in resilient people?
they have rapid glucocorticoid responses to stress which are rapidly switched off
- they have decreases levels of IL6 after social stress
In rats, what can reduce stress responses?
chewing on an inedible object
