The Incredible Human Body - ABGs

I'm fairly sure not many of you have taken the time today to realize what your body is doing to keep you alive, but the fact is that your body is constantly working to keep itself in balance, like a tightrope walker over the Grand Canyon.

Today's example of awesomeness comes by way of the arterial blood gases or ABGs. For the sake of brevity and balance, here are the three most important ABGs: pH (acid-base level), paCO2 (level of carbon dioxide, an acid), HCO3 (level of bicarbonate, a base).

Normal blood pH is between 7.35-7.45, which is quite a small range if you think about it. Let's just say that bad things (like coma and death) start to happen when the body gets outside of these limits. In order to maintain pH balance there are two systems that come into play. Your lungs regulate the amount of CO2, while your kidneys produce or reduce HCO3 in the blood.

Here's where it gets fun. Say you take off at a dead run for one block. Now, if you aren't an experienced runner, your muscles are going to produce lactic acid (H3C6O3 - for those who are desperate to know). Lactic acid in the blood stream decreases the pH (making it more acidic). Your lungs compensate for this change by having you breath faster, blowing of CO2 (remember it's an acid), until the pH level returns to normal.

But what if your lungs weren't capable of removing CO2 fast enough? In the case of chronic lung diseases where a person is constantly struggling to remove CO2, the kidneys kick in and produce more HCO3, which brings the pH back into balance. This is a snapshot of the respiratory side of things. There is also the renal side, which deals directly with HCO3, but that is much more complicated. Just think diabetic ketoacidosis and you'll get the idea.

My point is, that this is only one tiny, brilliantly working, self-correcting system out of hundreds of thousands in the body. Once again, the human body is incredible!