What is stress?

Question 1

How is stress defined?

Answer 1

Response by the body to disturbance/demand triggering the stress response

Question 2

When is stress normal or managed?

Answer 2

On waking cortisol levels rise, increasing blood glucose to start the day. Cortisol should naturally tail off from this point = diurnal cortisol

Eustress vs distress

Question 3

Where do stressors come from?

Answer 3

Personal - our inner monologue and standards.
Work
Nutrition - are we replacing nutrients used in stress.
Environmental - toxins, EMF
Dysfunctional bodily functions - thyroid, poor detox, inflammation

Question 4

What are the 3 phases of stress?

Answer 4

1. Alarm: ‘fight or flight’, adrenalin - mobilise body and cortisol - glucose, pain threshold
2. Resistance phase: functioning with high cortisol levels but less optimally
3. Exhaustion phase: prolonged cortisol release = cortisol resistance at glucocorticoid receptors, depleted cortisol, no natural cortisol for day-day functioning

Hans Selye - based on wound healing

Question 5

What is the pathway for the stimulation and release of stress hormones?

Answer 5

HPAA - Hypothalamic Pituitary Adrenal Axis
Amygdala
Hypothalamus
Pituitary - adrenals - adrenalin (blood glucose)/noradrenaline (CV system/brain - sharp thinking)
AND
Pituitary - Corticotrophin releasing hormone (CRH) - adrenocorticotrophin releasing hormone (ACTH) - adrenals - cortisol (gluconeogenesis)
CRH signals Glutamate - main excitatory NT - hypothalamus - pituitary…..

Question 6

How does chronic stress promote cortisol resistance and continued HPAA dysfunction?

Answer 6

Desensitisation at glucocorticoid receptors
Reduced cortisol binding
Negative feedback = more CRH
CRH = Mast cell activation, noradrenaline = inflammation
Glutamate upregulated = fear response

Question 7

How does Cortisol increase blood pressure?

Answer 7

Cortisol surges = bind to mineralocorticoid receptors i.e. aldosterone, increasing BP - useful in ST but detrimental LT….. (high blood pressure - vessel wall damage = inflammation)

Question 8

What is the mechanism for adrenalin causing inflammation?

Answer 8

i.e. in response to physical injury, releases inflammatory cytokines to heal and repair - helpful in the ST = oxidative stress

LT adrenalin/cortisol = chronic inflammation

Question 9

How does cortisol promote insulin resistance?

Answer 9

Cortisol promotes gluconeogenesis and decreases glycogen synthesis = raised blood glucose.
Cortisol inhibits beta cells and decreases insulin secretion.
Visceral fat uptake.
Increase in highly palatable foods.
Impaired insulin sensitivity + hyperglycaemia = over eating

Question 10

How does cortisol impair reproductive function?

Answer 10

CRH suppresses GnRH disrupting release of FSH, LH and oestrogen, progesterone and androgens

Question 11

How does Cortisol impair immune function?

Answer 11

Decreases T-cell proliferation and T-helper cell receptor expression - cannot induce TH1 immune response

Inhibits macrophage, neutrophil NK cell activity

Question 12

How does stress suppress thyroid function?

Answer 12

Cortisol reduces TSH production

Glucocorticoids inhibit 5-deiodinase
activity which converts T4-T3

Increased T4 converted to rT3 with decreased T3 receptor responsiveness

Question 13

How does stress suppress the GIT?

Answer 13

Gut:brain axis
Reduction in secretions - IgA + HCL
Permeability
Reduction in motility
Dysbiosis
Ulcers, IBD, SIBO etc

Question 14

Does persistent stress lead to hyper or hypo activation of the HPAA axis?

Answer 14

Hyper
Associated with depression, metabolic disorders - hypertension, hyperglycaemia

Hypo - fatigue, irritability, pain, fibromyalgia

Question 15

How does stress affect the endocannabinoid system?

Answer 15

eCB is a modulator for many bodily functions including inflammation and pain. Suboptimal functioning is linked to migraines, depression, IBS, (eCB involved in gut brain x-talk) inflammation