Sleeping and Breathing (Part 1)

Sleeping and Breathing (Part 1)In Night Thoughts of a Classical Physicist, McCormack portrays a beleagered 19th century physicist struggling to cope with revolutionary advances in physics. The “ether” theory of light has been replaced by the daunting mathematics of quantum mechanics, and the insomniac scientist broods through the night about the fundamental nature of light as inferred from its global behavior. The nocturnal respiratory physiologist, studying breathing during sleep, also struggles to infer basic mechanisms from global behavior. He seeks to better understand respiratory control by observing changes in stimulus-response characteristics when sleep replaces wakefulness. These “night thoughts” are the broodings of a “classical” physiologist to understand a complex system from rather simple observations at the bedside. Doubtless, real progress will require more sophistication; nonetheless, these night thoughts have been amusing and revealing. buy flovent inhaler

Breathing, the Unique Skeletal-Motor Act
For all its marvels and hidden mysteries, sleep, like light, intrigues by the obscurity of its fundamental nature; we spend one-third of our life in an activity of unknown purpose and unknown benefit. The biological goal must surely be important since sleep entails considerable risk; suspension of vigilance increases the chance of predation. Sleep also entails another risk, suspension of supervisory control of a vital function, breathing. Falling asleep means that breathing is put on “automatic pilot,” a controller able to respond to many, but certainly not all, challenges. This is most notable during rapid-eye-movement (REM) sleep, as most respiratory muscles are inactivated. This stage of sleep poses a particular challenge to maintenance of the ongoing motor output required for breathing. The central fact is that breathing is the only skeletal-motor act that continues during sleep. Convective transport of gas into and out of the lungs must be maintained when the nervous system has, from the external viewpoint, “shut down.”