How diaphragmatic breathing can reduce anxiety

write article that explores how the human body responds to perceived and actual stress (Fight or Flight) in relation
to increased heart rate, adrenaline, cortisol, vasoconstriction, etc and how that has the potential to negatively
impact emotional control and decision making – even when the threat is non-physical, e.g. when someone feels nervous
before speaking in public. Furthermore, I want the article to explain how and why deep breathing / diaphragmatic
breathing reduces some of the negative symptoms of a system going into overdrive (e.g shaking legs, dry mouth, loss
of peripheral vision, etc).