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Maintaining Blood pH

Maintaining Blood pH


This lesson will examine the kidneys role in maintaining blood pH.

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Source: Video and Images Created by Amanda Soderlind

Video Transcription

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Welcome to this lesson on maintaining blood pH. Today we will be discussing the kidney's role in maintaining the blood pH.

So kidneys are an organ of the body that help maintain the body's acid-base balance. So the acid-base balance is the amount of acids and bases found in extra cellular fluids of the body.

So a normal body pH is between 7.37 to 7.43. Now if you're familiar with the pH scale, you know that a pH of seven is neutral, and a pH of less than seven is acidic, and a pH of more than seven is basic. So if the pH of the body is 7.37 to 7.43, that's slightly more than seven, which means that the normal pH of the body is slightly basic.

So in order for our body to function properly, in order for our cells and enzymes to function optimally, this pH needs to stay within this range. So if it's not maintained, or if it gets really far out of range, severe problems can occur.

So the pH is managed by eliminating excess hydrogen ions, which are acidic and restoring bicarbonate buffers. So bicarbonate is a basic substance.

So our body has these mechanisms in order to help maintain our blood's pH. So for example, if blood is too acidic, meaning that the pH is low, then what the body is going to do is it's going buffer excess hydrogen ions with bicarbonate. So bicarbonate will buffer excess hydrogen ions.

So acids and bases-- when they combine-- help to neutralise one another. So if the blood is too acidic, or there's too many hydrogen ions in the blood, then bicarbonate will help to buffer some of those extra hydrogen ions. So more bicarbonate will be released into the blood in order to buffer those extra hydrogen ions and then bring the pH back to a normal range.

If blood is too basic, meaning that the pH is high or higher than normal, then less bicarbonate is released into the bloodstream. So if the blood is too basic, less carbonate will be released into the bloodstream, therefore less hydrogen will be buffered. And so this will help to, again, bring that pH back to a normal level.

So things that can cause the blood to become too basic would be severe dehydration, or overuse of antacids, or sometimes hormone disorders can cause the blood to become too basic. And then in that case-- as I mentioned-- less bicarbonate would be released into the bloodstream, so that less hydrogen will then be offered to return that pH back to a homeostatic level.

So this lesson has been an overview on how the kidneys help to maintain the body's acid-base balance.

Terms to Know
Acid-Base Balance

The amounts of acids and bases in the extracellular fluids of the body; amounts of acids vs. bases affects the overall pH of extracellular fluids.