Fight or flight

Question 1

What is the amygdala and hypothalamus’ role in fight or flight?

Answer 1

When faced with a threat the amygdala is mobilised (amygdala associates sensory signals with emotions associated with fight or flight e.g. fear or anger)
The amygdala then sends a distress signal to the hypothalamus, which functions like a command centre - communicates with rest of body through sympathetic nervous system

Question 2

How does the body respond to acute (sudden stressors)?

Answer 2

1. The sympathetic nervous system is triggered, begins the process of preparing body for rapid action
2. Sends signal through adrenal medulla which releases adrenaline into bloodstream
3. Adrenaline circulates through body - heart beats faster, breathing becomes more rapid and triggers release of blood sugar (supplies energy)
4. When threat has passed, the parasympathetic nervous system dampen down stress response - brings heartbeat down and reduces blood pressure + bodily processes that were inhibited when SNS was aroused such as digestions begins again

Question 3

How does the body respond to chronic stressors?

Answer 3

1. Brain continues to perceive something as threatening - 2nd system kicks in
2. Hypothalamus activates the HPA axis
3. H - hypothalamus - in response to continued threat it releases a chemical messenger - CHR - released into blood stream
4. P - pituitary gland - CRH causes the pituitary gland to produce and release ACTH - which is then transported in the bloodstream to its target site - adrenal glands
5. A - adrenal glands - ACTH stimulates the adrenal cortex to release various stress related hormones e.g. cortisol which can have positive effects (e.g. a quick burst of energy + lower sensitivity to pain) and negative effects (e.g. impaired cognitive performance and a lowered immune system
6. System is very efficient at regulating itself - hypothalamus and pituitary gland have special receptors that monitor cortisol levels (can initiate reduction, bringing levels back to normal)

Question 4

Why can it be argued that females may respond to stressors/threats differently?

Answer 4

Taylor et al - tend and befriend
Involves protecting themselves and their young through nurturing behaviours (tending) and forming protective alliances (befriending) - women may have a different way of responding to stress because their responses evolved in the context of being the primary caregiver (fleeing at any sight of danger would put offspring at risk)
PREVIOUS research was largely focused on males and has obscured patterns of stress response in females (Beta bias -assume findings will apply to women)

Question 5

Why may fight or flight not tell the whole story?

Answer 5

Gray - prior to responding with attacking or running away most animals (including humans) typically display a freeze response - essentially a ‘stop, look and listen’ response where the animal is hyper-vigilant, alert to the slightest sign of danger
The adaptive advantages of this for humans is that freezing focuses attention and makes them look for new information in order to make the best response

Question 6

What genetic evidence is there for sex differences in the fight or flight response?

Answer 6

Lee and Harley - the SRY gene (found exclusively on the make Y chromosome =) directs male development promoting aggression and resulting in fight or flight - SRY gene may prime males to respond to stress in this way by releasing adrenaline
In contrast, the absence of the SRY gene in females may prevent this response to stress - leading instead tp ‘tend and befriend’ behaviours