QUESTIONS AND ANSWERS GRADED A+
Define stress
an independent risk factor for many diseases; occurs when the stressor(s) outweigh
the individual's ability to cope or adapt
Define Seyle's General Adaptation Syndrome
the three-stage process that describes the physiological changes your body goes
through when under stress
Describe the 3 phases of Seyle's General Adaptation Syndrome
1. alarm reaction (fight or flight)
• massive release of adrenaline
• increased cortisol
2. resistance (↓ in fight or flight)
• more coritsol secretion
3. exhaustion (body can no longer resist)
,• decreased cortisol
• adrenocortical exhaustion
Describe Seyle's Triad (General Adaptation Syndrome)
• enlargement of adrenal gland (RAAS)
• atrophy of thymus gland (not producting proper T cells)
• development of gastric ulcers
List the hormones associated with stress response
stress = ↑ production of hormones
• catecholamines (norepi & epi)
• corticotropin-releasing factor (CRF)
• adrenocorticotropic hormone (ACTH)
• glucocorticoid hormones (cortisol)
• mineralocrticoid hormone (aldosterone)
• antidiuretic hormone (ADH, vaso pressin)
Where is CRF released from?
hypothalamus
,What is the physiologic effect of CRF?
stimulates ACTH release
Where is ACTH released from?
anterior pituitary
What is the physiologic effect of ACTH?
stimulates the synthesis and release of cortisol
Where is cortisol released from?
adrenal cortex
Describe the neuro-endocrine response to stress - epinephrine and norepinephrine
production
sensory input → thalamus → cerebral cortex (triggers vigilance, cognition, focused
attention) → limbic system → hypothalmus → locus ceruleus → autonomic
nervous system → stimulation of adrenal medulla → release of epinephrine and
norepinephrine
Describe norepinephrine (catecholamine)
, released by the adrenal medulla
• increases BP through vasoconstriction (sympathetic)
• decreases gastric secretions
• dilates pupils
• dilates bronchial airways
Describe epinephrine (catecholamine)
released by the adrenal medulla; more cardiac affects
• increases BP by increasing HR, venous return & CO
• increased muscle stregth
• promotes glucose formation (saves energy for CNS, similar to cortisol, FIGHT &
FLIGHT)
Describe the neuro-endocrine response to stress - coritsol production
sensory input → thalamus → cerebral cortex (triggers vigilance, cognition, focused
attention) → limbic system → hypothalmus stimulation → release of CRF →
anteriory pituitary gland stimulation → release of ACTH → adrenal cortex
stimulation → release of cortisol
Causes of low cortisol
• low CRF = problem w/ hypothalmus
• low ACTH = problem w/ anterior pituitary