Rasheed's entire nervous system most likely screamed out in pain.
Explanation:
The nervous system sends out a sort of signal whenever something either hurts you, such as kicking a wall or bumping your head on the ceiling. That signal, thanks to the nervous system, gets sent to your brain that tells it that something is in pain. Once the brain receives that message, it'll let you react based on how you feel about it.
So, in this case, Rasheed just let out a yelp whenever he hit that desk with his leg. <em>Ouch.</em>
