Although it has been called the "Fight or Flight Hormone" adrenaline can be better described as 'Do it NOW!!! hormones." First things first, notice the 's.' Adrenaline isn't just one thing, but a cocktail of chemicals and hormones. For a more technical (but still a layman's) explanation look at what Wikipedia has to say about adrenaline.
Hmm. Usually to my layman's eye the author seems to know what he's speaking about BUT this time I'm surprised. I always thought adrenaline was a name for a single specific hormone rather than "a coctail of chemicals and hormones". Even the Wikipedia page the author himself links to doesn't seem to treat adrenaline as a collective term for many hormones; on the contrary it gives adrenaline one particular chemical formula, C9H13NO3
Is there more than 1 substance that can legitimately be called adrenaline?