ABSTRACT
During wakefulness, breathing is exquisitely controlled to produce precise regulation of arterial blood gases with minimal metabolic demand from the respiratory muscles, such that following perturbations (e.g. sigh, vocalization, or swallowing) the system is able to adjust within seconds to maintain homeostasis. The characteristics of the respiratory control system awake are the high gain of the chemo and mechanical sensory feedback systems, plus the input from cortical respiratory centers. During sleep many of these characteristics are compromised, exposing difficulties in breathing.
