Hi tad, so adrenaline doesn't really affect the brain like alcohol (in terms of reducing inhibition) but it does allow us to focus on one percieved threat. As such we're more likely to ignore other things that we'd often consider threats (ie: social stigma)...
Adrenaline itself doesn't change how well we use our muscles (how well we recruit them) but it can increase blood flow.
More importantly however is that when we get a surge that releases adrenaline, adrenaline isn't the ONLY thing being released. Our brain in switching to flight-or-fight tones out pain, fear and reason. This is why people who're 'hyped up' often don't feel the injuries they sustain till AFTER the event. :)