Answer :
When you sleep, your lungs go through various ventilation cycles. As your brain shifts from an active state when you are awake to a more passive state when you first fall asleep, your lungs adapt to this by changing its rate of ventilation.
When you sleep, your lungs go through various ventilation cycles. As your brain shifts from an active state when you are awake to a more passive state when you first fall asleep, your lungs adapt to this by changing its rate of ventilation.