Flying high without fear

1.	a) Anxiety is mainly due to the release of which hormone?
   	b) Why is this hormone sometimes referred to in the context
	of "fight, flight & fright?"

2.	The release of the hormone causes constriction of the blood vessels
	of the digestive system and skin.
	a) How might this hormone be responsible for white knuckles?
	b) Which organs are likely to need an improved blood supply? 

3.	What differences in the pressure and composition of the air in an aircraft 	might be partial physical, as opposed to psychological, causes of fear?