The fight-or-flight response Flashcards
What is the fight or flight response?
Survival mechanism that triggers a sequence of activity in the body when it is preparing itself for defending/attacking or running to safety.
What is the acute stressors response known as?
Sympathetic Adrenal Medullary (SAM) response.
What immediately happens in the brain when we are faced with a threat?
Amygdala associates sensory information with fight or flight emotions and sends a distress signal to the hypothalamus. Communicates fight or flight response to rest of body through sympathetic nervous system (SNS).
What does the SNS do when it is triggered by an acute (sudden) stressor?
Sends signal to adrenal medulla to release adrenaline and noradrenaline into bloodstream.
List physiological changes that adrenaline causes as it circulates the body (acute stressor response).
Heart beats faster, blood pressure increases, breathing rate increases, release of glucose and fats into bloodstream, digestion inhibition, pupil dilation.
What is the role of the parasympathetic nervous system in the fight-or-flight response?
Relaxes the body to reduce the stress response once the threat has passed. (Restores heart rate, blood pressure, digestion etc.)
Outline the role of adrenaline in the fight or flight response (6 marks).
Response to acute stressor - hypothalamus activates sympathetic NS.
SNS send signal to adrenal medulla.
Releases adrenaline (and noradrenaline) into bloodstream.
Adrenaline prepares body for fight or flight:
Increased heart and breathing rate and increased blood pressure - more O2 for physical action
Diverts blood from digestive system so O2 used in more useful areas (brain & muscles).
If the brain continues to perceive something as threatening it becomes a chronic stressor. What system is activated when this is the case?
The HPA axis.
What does the HPA axis consist of?
Hypothalamus
Pituitary gland
Adrenal glands
How does the HPA axis respond to chronic stressors?
Hypothalamus releases CRH hormone into bloodstream. Pituitary gland (in response to CRH) releases ACTH hormone into bloodstream. Stimulates adrenal cortex to release stress related hormones such as cortisol.
Name 2 positive and 2 negative effects of cortisol in the body.
Burst of energy and lower sensitivity to pain.
Impaired cognitive performance and lowered immune response.
(AO3) What has been suggested as the more common response in females?
Tend and befriend response. Protect themselves and young by nurturing child and forming protective alliances with other females. Different response to stress due to context of being the primary caregiver (running away puts infant at risk). Oxytocin important role here. Overall beta gender bias in fight-or-flight.
(AO3) Why may fight or flight not tell the whole story?
Fight, flight or freeze. Most humans and animals freeze upon initial exposure. Stops, increases alertness, looks for signs of danger to decide on appropriate response. More adaptive response (better for survival) than simple fight or flight.
(AO3) What are the negative consequences of fight or flight now?
May not be an evolved/adaptive stress response that increases our survival chances. Purpose of fight or flight is to protect us when our lives in physical danger by physically stimulating us. Modern stressors rarely require physical activity. Causes problems for humans when constantly activated - increased blood pressure, damage blood vessels + heart disease D:
(AO3) Explain how the fight or flight response is overly deterministic.
Suggests the response is inevitable when exposed to a stressor. Cognitive and environmental factors may also have an important impact. E.g. past experience of stressor (knows not a threat) may prevent response. Also biologically reductionist. Needs to consider more factors.
