Sleep is a vital, highly organized process regulated by complex systems of neuronal networks and neurotransmitters. Sleep plays an important role in the regulation of central nervous system and body physiologic functions. Sleep architecture changes with age and is easily susceptible to external and internal disruption. Reduction or disruption of sleep can affect numerous functions varying from thermoregulation to learning and memory during the waking state.
Markov, Dimitri and Goldman, Marina, "Normal sleep and circadian rhythms: Neurobiologic mechanisms underlying sleep and wakefulness" (2006). Department of Psychiatry and Human Behavior Faculty Papers. Paper 2.