After the bank robbery, the very frightened people probably experienced increased activation of the sympathetic nervous system, stimulation of the adrenal medulla, and the release of the hormone(s) called:

The answer is Adrenaline

Adrenaline is a stress hormone secreted by the adrenal glands and some other neurons when a person is frightened, excited or generally in stress.

It prepares our body for it's 'fight or flight' mechanism and tightens muscles for exertion.

After a bank robbery, most people feel a rush of adrenaline.

Digestion because it removes waste