What does our respiratory system do while we sleep? In this look at the “Mechanics of Sleep”, we will take a closer look.
THE MECHANICS OF SLEEP: RESPIRATORY SYSTEM
During sleep our body goes through many changes, from brain activity to hormone release. Our bodies are very busy during the so called “inactive” state of sleep. In this blog I will focus on the changes that occur in the respiratory system when we enter sleep.
RESPIRATORY DRIVE
The process of respiratory drive detects the change in carbon dioxide (the gas we expel) and oxygen (the gas we inhale). During all stages of sleep, this drive loses sensitivity and doesn’t respond as quickly as when awake. This causes ones minute ventilation to decrease by 10-15%. In other words, as we sleep breathing slows down and we do not take in or expel as much air as when awake. As muscles relax during sleep, the upper airway narrows and leads to 200% increase in upper airway resistance. As a result, respiratory muscle activity is reduced and increased work of breathing is needed.
ENTERING REM
Finally as we enter stage 5 sleep (commonly referred to as REM) our body becomes paralyzed. Body paralysis is believed to stop us from acting out our dreams. When we enter this state our ventilatory needs are maintained solely by our diaphragm.
OUR SLEEP IS SO IMPORTANT
It’s easy to see how this delicate balance can easily be effected by other health issues such as COPD, ALS, and even obesity. These plus numerous other health issues can exacerbate ones sleep problems and often leads to a lack of restorative sleep and/or even a sleep disorder such as obstructive sleep apnea (OSA).
I hope that by giving you an understanding of the respiratory system and the mechanics of sleep you will begin to understand the complexity that is sleep and how healing and health are compromised when sleep is elusive.