Question

Why do humans normally have heigher rates of respiration in the day than they do at night

Answer 1

Answer:

Some of it may be due to throat muscles relaxing. It may also be due to less movement of the rib cage during REM sleep (REM stands for rapid eye movement). Whenever you're sleeping, your oxygen levels are lower and your carbon dioxide levels are higher because your level of breathing goes slightly down.

so humans normally have higher rates of respiration in the day than they do at night.