Stress / Fight or Flight

Question 1

Fight or Flight

Answer 1

• A stress response that is hard wired into our brains
• Comes from evolutionary adaptation designed to help organism survive danger

Question 2

Amygdala

Answer 2

• Processes threatening stimuli
• Sends distress signal to hypothalamus when exposed to threat, which coordinates F/F response by communicating with the body through the sympathetic NS

Question 3

Acute Stress

Answer 3

• Short term stress
• Acute stressors dealt with by Sympathomedullary Pathway (SAM)

Question 4

Steps of Acute Stress

Answer 4

1) Amygdala receoves distress signal, transfers to hypothalamus
2) Hypothalamus activates adrenal medulla
3) Medulla secretes Adrinaline
4) Adrenaline leads to arousal of Sympathetic NS and reduced activity in Parasympathetic NS
5) Once threat is over, Parasympathetic NS takes over and balances body
6) No negative effects, survival value

Question 5

Chronic Stress

Answer 5

• Stress that continues for extended period of time without stopping
• Hypothalamic-Pituitary- Adrenal (HPA) axis deals with chronic stressors

Question 5

Steps of Chronic Stress

Answer 5

1) Stressor activates HPA axis
2) Hypothalamus releases CRH (Corticotropin-releasing hormone), which acts as central regulator
3) CRH makes anterior pituitary gland release ACTH (Adrenocorticotropic hormone)
4) ACTH binds to receptors in adrenal cortex, where cortisol is released

Question 6

Positive actions of Cortisol

Answer 6

• Releases stored glucose from the liver for energy
• Reduces swelling after injury

Question 6

Negative actions of Cortisol

Answer 6

• Suppresses immune system
• Impairs cognitive function