Biopsychology: Fight or flight response Flashcards
What happens when a threat is presented?
the amygdala is mobilised
What is the flight or fight response?
A physiological reaction that occurs in response to a perceived harmful event, attack or threat to survival
What does the amygdala do once it is mobilised due to a threat?
Sends a distress signal to the hypothalamus which communicates with the rest of the body through the sympathetic NS
What is the amygdala responsible for?
The perception of emotions such as anger and fear
What system is used for a an acute stressor?
Sympathetic-medullary pathway
What are the 2 systems used in response to a stressor
acute stressor = Sympathetic-medullary pathway (SAM)
Chronic stressor = Hypothalamic-pituitary-adrenalcortical axis (HPA axis)
What system is used for a chronic stressor?
Hypothalmic-pituitary-adrenalcortical axis
What happens after the sympathetic nervous system is triggered by a distress signal received from the hypothalamus?
It sends a signal to adrenal medulla
Adrenal medulla responds by releasing adrenaline and noradrenaline into the bloodstream
Where does the sympathetic nervous system receive a distress signal from?
The hypothalamus
What happens when adrenaline circulates around the bloodstream?
It causes physiological changes that prepare the body for the FOF response
What are the physiological changes the body undergoes when adrenaline is in the bloodstream?
increased heart rate and elevated blood pressure increased breathing rate Slowed/stopped digestion Salvation stops = mouth dry Pupils dilate
Why does heart rate increase and blood pressure elevate as a result of the FOF response?
This will increase blood supply to muscles to assist a reaction
Why does breathing rate increase as a result of the FOF response?
A quicker breathing rate takes in more oxygen to power the muscles, in turn making the body more able to respond
Why does digestion slow/stop as a result of the FOF response?
Blood is diverted away from the digestive system by vascular constriction in vessels, which can lead to feelings of nausea ‘butterflies’. Non-essential systems are shut down so blood flow can increase to the muscles instead
Why does salvation stop as a result of the FOF response?
so energy can be diverted towards muscles instead
What does adrenaline trigger?
Triggers the release of glucose in the form of glycogen, which flows into the bloodstream, supplying energy to parts of the body associated with the FOF response
What happens once a threat has passed?
The parasympathetic nervous system dampens down the stress response by slowing back down heart rate and reducing blood pressure
What is a characteristic of the parasympathetic nervous system?
slow acting, so make take several minutes for body to return to normal state
When does the hypothalamus activate the stress response system HPA Axis?
If the brain continues to perceive something as threatening, the initial surge of adrenaline subsides
and the hypothalamus activates a stress response system
What activates the HPA axis?
Hypothalamus
What does the hypothalamus do in the HPA axis?
Releases a chemical messenger (CRH) into the blood stream in response to the stressor
What does CRH target?
Pituitary gland
What does the pituitary gland release once is it stimulated by CRH?
ACTH
What gland does ACTH target once it is released by the pituitary gland, and what does this target gland release?
The adrenal cortex
releases cortisol
Why is cortisol bad?
Has negative effects, makes person more susceptible to:
Headaches
Digestive problems
Anxiety
Depression
Also suppresses the immune system so can’t fight infections as effectively.
Why do pupils dilate as a result of the FOF response?
To take in as much light as possible
What is the purpose of the FOF response?
It is a survival mechanism which enables animals and humans to react more quickly to life-threatening situations
When does the immune system get suppressed?
After cortisol is released into the bloodstream
What is another name for noradrenaline?
Norepinephrine
What dampens down the stress response by slowing back grown heart rate and reducing blood pressure?
Parasympathetic nervous system
