fight or flight response Flashcards
What is the fight or flight response?
A sequence of activity within the body that is triggered when the body prepared itself for defending or attacking or running.
- Evolutionary survival mechanism in response to a threat
- Primes the body for extreme action → returns to homeostasis after the threat has passed
What is a stressor?
brings on a stress response
What are the two types of stressors ?
acute and chronic
what is an acute stressor?
short term immediate response
What is a chronic stressor ?
long term stres response due to prolonged emotional processor
What is the process of fight or flight - 3 steps?
1) Threat
2) Amygdala mobilises : associating sensory signals with emotions associated with flight or fight
3) It sends a distress signal to the hypothalamus that then communicates rest of body via ( sympathetic nervous system)
what is adrenaline ?
Adrenaline role is to be secreted from adrenal medulla in response to a stressor travels to target cells to enact physiological changes that help the body to deal with stressor
where does adrenaline secrete from and where does it travel to?
Adrenal medulla
and travels to target cells to cause physiolgical changes
What is the acute stress response process?
- Stress is recognised
- Amygdala sends a distress signal to the Hypothalamus
- Hypothalamus activates sympathetic branch of (autonomic ns)
- This signals to the Adrenal medulla which releases adrenaline into the bloodstream
- As this adrenaline circulates physiological changes → increased breathing / blood pressure / increases release of fats and blood sugar providing energy for result
- After threat has passed parasympathetic system releases acetylcholine to calm down
Acute stress response flow diagram
Amygdala → Hypothalamus → sympathetic system → adrenal medulla → adrenaline → stress passes → parasympathetic nervous system → returns to normal
Respone to chronic stress what is the system called and what activates it?
The hypothalamus activates a stress system of HPA axis
Chronic stress response - 4 steps
1) Hypothalamus activates (using CRH) the pituitary gland
2) The CRH causes the pituitary gland to release ACTH which activates the Adrenal cortex
3) The adrenal cortex consequently releases Cortisol
Cortisol → increases blood sugar and suppress the immune system
4) Once the threat passes, parasympathetic system calms the body, but the hypothalamus can monitor cortisol levels and reduce CRH / ACTH feedback loops
chronic stress feedback
- If levels rise above the threshold, the hypothalamus and pituitary gland initiate a reduction in CRH and ACTH levels
Feedback
Both hypothalamus and pituitary gland have special receptors that monitor circling cortisol levels → if they rise above normal they initiate a reduction in CH and ATCH bring cortisol levels back down
outline role of adrenaline in fight or flight
Adrenaline role is to be secreted from adrenal medulla in response to a stressor travels to target cells to enact physiological changes that help the body to deal with stressor
Increases heart rate
Inhibited digestion → mouth goes dry
Sweating → lose grip of wheel
Once stressor past → feel normal due to parasympathetic system restoring these physiological changes
Distinguish between the actions of the sympathetic and the parasympathetic systems in the fight - or flight- response
Sympathetic → bring changes to help the body → increase hr / inhibit digestion to allow body to deal with stressor
Parasympathetic → once stressor past reverse the changes → restore heartrate/ digestion