EVERY BREATH YOU TAKE
by Arthur W. Siebens, Ph.D., Copyright 2001
to the tune of “Every Breath You Take,” by Sting, as performed by The Police

Every breath you take, every move you make
Every bond you break, every step you take
You get O2 through you.
Your mouth (and nose) is the inlet, the trachea lets you jet
Air where you bronchi get, air to the bronchiole net
To get O2 through you.
Can’t you see why? In the alveoli
Hemoglobin’s resupplied, all (four O2) sites are occupied.
Now, the transit time’s short (time in capillary ~0.75 sec), O2 you must transport (O2 equilibration time ~0.25 sec)
CO2 you must export, and I’m glad to report
You get O2 through you.
Respiration also controls acid-base, and by measuring CO2 through pH
(CO2 + H2O — H2CO3 — H+ + HCO3)
The medulla controls your breathing pace, so any extra CO2’s erased
Don’t want to be dying? Baby, BREATHE!
If blood O2’s too low, your breathing rate’s too slow
There’s back up O2 drive (sensors in the aortic arch and carotid arteries), to help you to survive
To get O2 through you.

To help O2 (and CO2) diffuse, the surface area’s huge (~70 m2, 300 million alveoli in a pair of lungs)
Your CO2’s removed, your blood O2’s renewed
You get O2 through you.
The PO2 is high (~100 mm Hg), in the alveoli
The blood O2 is low (PO2 ~40 mm Hg),
So to the blood it goes.
Now, when you want to breathe, you can breathe with ease
Contract your diaphragm (and intercostal muscles), inward the air will ram
To get O2 through you.
Every breath you take, every move you make
Every bond you break, every step you take
You get O2 through you.
Every breath you take
Every breath you take.