Final answer:
The glymphatic system is the system in the brain that helps rid the brain of wastes, primarily during REM sleep.
Step-by-step explanation:
The system in the brain that serves as an overnight 'clean-up crew' to help rid the brain of wastes is the glymphatic system. It is responsible for clearing out toxins, metabolic waste, and other harmful substances from the brain. This system is most active during sleep, especially during REM sleep, which is characterized by rapid eye movement. During REM sleep, the glymphatic system flushes out waste products, such as beta-amyloid protein, which is associated with Alzheimer's disease. It is not the lymphatic system or the immune system that primarily performs this function, although they both have roles in supporting the brain's overall health and function.
Learn more about The role of the glymphatic system in clearing out waste from the brain during sleep