ABSTRACT
Respiration is a highly regulated physiologic function designed primarily to maintain homeostasis of PaO2, PaCO2, and pH over a wide range of human activities. Physical exertion, infection, and other physiologic stresses require increased metabolism and the respiratory system must respond with great precision to prevent hypoxia, acidosis, tissue injury, and even death. In addition to homeostatic functions, more specialized intermittent tasks requiring respiratory control include speech and activities needing breath-holding or forceful ventilatory efforts, such as micturition, defecation, emesis, coughing, parturition, inflation of a balloon, or playing a brass instrument. Sleep substantially influences respiratory control, and some of the most common sleep disorders involve abnormal breathing patterns, often termed “sleeprelated breathing disorders” (Table 8.1) (1). To understand these disorders, a review of key concepts in respiratory physiology and the effects of sleep on pulmonary function is necessary.
PHYSIOLOGY OF RESPIRATION DURING WAKEFULNESS AND SLEEP
