Final answer:
The brain site involved in your level of alertness is the reticular activating system (RAS). The RAS is a network of neurons located in the brainstem that regulates and controls wakefulness, attention, and arousal.
Step-by-step explanation:
The brain site involved in your level of alertness is the reticular activating system (RAS).
The RAS is a network of neurons located in the brainstem that regulates and controls wakefulness, attention, and arousal. It receives sensory information from various parts of the body and acts as a filter, determining which information is important and should be brought to your conscious attention.
For example, when you are in a state of high alertness, such as during an important exam or an intense sports game, the RAS is activated and helps keep you focused and alert.