MedicCastExtra pH Scale -Hi, this is Jamie Davis, the Pod Medic. And we're talking about acid base balance today-- understanding pH, specifically in this installment. What is pH? So what is pH? Well, pH stands for the measurement of hydrogen ions present in a particular substance. That hydrogen ion concentration-- p, percentage, hydrogen. So that's what pH stands for. One of the things that messes people up about pH, though, is that it is an inverse logarithm. So let's talk about this for a minute. Inverse logarithm, what's that mean? Logarithm is a scale where each time you increase by a factor it increases by 10 times. So if you go from a pH of 7 to a pH of 8, it is 10 times more alkaline at a pH of 8 than it is at 7. And this continues all the way up the scale. Other things that are logarithmic scales, we have logarithmic scales for the Richter scale. This is the measurement of the severity of an earthquake. That means that an earthquake that is measuring 6 on the Richter scale is 10 times stronger than an earthquake measuring 5 on the Richter scale. So this is what a logarithmic scale does. pH is really confusing though, because it's an inverse logarithm. As the percentage of hydrogen ions increases, the number on the pH scale goes down. And this is what messes people up. When something is more acidic, it has a lower pH. And it doesn't make sense and it doesn't mean a whole lot to those of us that are trying to memorize this stuff. But that's what causes issues. So what is the safe pH range in a human being? Generally accepted, the numbers are 7.35 to 7.45 pH. And that means that we're slightly alkaline. We aren't very acidic. We like to be a little bit above normal because that's the way our systems are. We like to be buffered and against acidity, and so we try to fight against acidosis in our homeostasis. So I came up with the seesaw thing to help you understand how pH works. You'll see on the left hand side, the pH scale going from 1 up to 14. 7 is normal. Anything higher than 7 is considered alkaline. Everything lower than 7 is considered acidic. So you have this scale. And you can see that if you use a seesaw, this visual will help you understand that as the number goes lower, the acidity increases. And consequently, as the number goes higher, it becomes more basic or more alkaline. And you can see that illustrated here. So remember this seesaw when you're thinking about pH. And it will help you get a handle on the pH system. Here's a look at our references for this particular short segment on pH. And if you'd like to find out more information, you can head over to Mediccast.com. Or find the great student resources available at MedicCastExtra.com. This has been a MedicCast Podcast Extra Production.