Stress and Fatigue - Physiological Effects of Stress and Effects of Prolonged Cortisol Secretion: Flashcards
Q: What happens if a stressor is perceived as too intense or lasts too long?
A: Maladaptive responses can occur, leading to disease.
Q: Where are glucocorticoid receptors expressed in the body?
A: In most organs and tissues, including brain regions, sympathetic nerves, and immune cells.
Q: How does hyperactivation of the HPAA affect the body?
A: It can cause widespread effects, including cortisol dysfunction, unmodulated inflammation, pain, depression, GI issues, and increased risk of cardiovascular disease and cancer.
Q: What is cortisol resistance, and how is it caused?
A: Cortisol resistance occurs when prolonged or excessive cortisol secretion desensitises glucocorticoid receptors to cortisol.
Q: What role does CRH play in cortisol dysfunction?
A: CRH increases mast cell activation, noradrenaline release (pro-inflammatory), and upregulates glutamate in the amygdala to promote a fear-based response to stress.
Q: How does stress-induced inflammation contribute to disease?
A: It is implicated in conditions such as CVD, fibromyalgia, chronic fatigue syndrome, osteoporosis, rheumatoid arthritis, IBD, chronic back pain, and TMJ dysfunction.
Q: What are the effects of inflammation caused by stress?
A: It increases oxidative stress, free radical damage, cellular death, ageing, and systemic tissue damage.
Q: How is inflammation a part of the stress response?
A: The sympathetic response to stress is pro-inflammatory, useful in the short term but contributing to chronic inflammation under prolonged stress.
Q: How does prolonged cortisol secretion increase the risk of Type 2 diabetes?
A: Cortisol increases gluconeogenesis, decreases glycogen synthesis, inhibits beta cell insulin secretion, and impairs insulin-mediated glucose uptake.
Q: How does prolonged cortisol secretion contribute to weight gain?
A: Cortisol stimulates appetite for highly palatable foods, redistributes fat to visceral cells, and promotes overeating by impairing insulin response and raising hunger signals.
Q: What is the effect of chronic stress on reproductive function?
A: Chronic stress suppresses GnRH, disrupting FSH and LH release, which impairs oestrogen, progesterone, and androgen production.
Q: How does prolonged cortisol secretion impair immune function?
A: It decreases T-cell proliferation, downregulates T-helper cell receptor expression, and inhibits neutrophil, macrophage, NK cell, and lymphocyte activity.
Q: What are the effects of cortisol on thyroid function?
A: Cortisol reduces TSH production, inhibits 5-deiodinase activity, shunts thyroxine into inactive rT3, and decreases T3 receptor responsiveness during adrenal fatigue.
Q: How does ongoing stress affect gastrointestinal function?
A: It alters GI motility, increases visceral perception, changes GI secretions (e.g., reducing HCl production), and increases intestinal permeability, leading to various GI disorders.
Q: What clinical consequences arise from stress-induced gastrointestinal changes?
A: Conditions such as GORD, peptic ulcers, IBD, and SIBO.
