How stress affects the endocrine system

Contributors

The hormonal cascade of the fight or flight response which is the emotional aspect of the stress reponse propogates through three main steps

Stimulation of the hypothalamus by the amygdala causes the release of corticotrophin-releasing factor (CRF).
CRF then stimulates the pituitary gland causing release of adrenocorticotrophin (ACTH) into the bloodstream
ACTH travels through the bloodstream and stimulates the adrenal glands causing the release of ephinephrine (adrenaline) and glucocorticoids including cortisol.

Dilates pupils
Increases heart rate, stroke volume and bp (blood flow may actually increase 300-400% in some cases)
Constricts arterioles which serve the internal organs and the skin
Dilates arterioles which serve the legs & arms
Stimulates release of glucose from body stores through two pathways
- Glycolysis splits glycogen stores to release glucose into the bloodstream
- Fat metabolism is increased which also releases glucose into the bloodstream
Suppresses immune system
Increases breathing rate

Increase blood pressure
Stimulate release of glucose from body stores through three pathways
- Glycolysis splits glycogen stores to release glucose into the bloodstream
- Fat metabolism is increased which also releases glucose into the bloodstream
- Protein is broken down
Inhibits converstion of glucose into glycogen (glycogenesis)
Anti-inflammatory effects
Slows down healing
Suppresses immune system
Inhibits secretion of CRH (creating a negative feedback cycle)
Inhibits bone formation

New research is proving the involvement many other biochemicals in the stress response