Functions of kidney 3: acid-base balance

Functions of kidney 3: acid-base balance

Have you ever wondered what the kidneys do and why they’re so important? Or how the kidneys are involved in acid-base balance?

This article will cover what the kidneys are and one of the main functions of the kidney: acid-base balance.

Acid-base balance

This article will focus on the role of the kidneys in acid-base balance.

We will be addressing the following questions:

1. What is meant by acid-base balance?
2. What is pH?
3. What is the role of the kidneys in acid-base balance?
4. What happens if acid-base is not controlled?

Click here to learn more about the functions of the kidneys.

1. What is meant by acid-base balance?

Acid-base balance is the body’s balance between acidity and alkalinity (bases). This is controlled very specifically because slight changes away from the normal values can have significant effects on vital organs and processes within our body.

The body uses different mechanisms to ensure acid-base balance is controlled and regulated. The organs primarily involved in this are the kidneys and the lungs.

Your acid-base balance is determined by measuring the pH and levels of carbon dioxide (an acid) and bicarbonate (a base) present in the blood.

2. What is pH?

pH is the measurement of acidity or alkalinity of solutions like blood.

The pH scale ranges from 0 (highly acidic) to 14 (highly alkaline). A value of 7.0 is neutral.

The normal pH of the blood is 7.35-7.45. Any value lower than this indicates that there is more acid in the blood. Any value higher than this indicates the blood is more alkaline.

3. What is the role of the kidneys in acid-base balance?

Different mechanisms are in place to ensure acid-base balance is controlled and regulated in the body. As previously mentioned the main organs involved are the kidneys and the lungs.

The kidneys are able to alter the pH of the blood because they have the ability to remove (excrete) excess acids or bases as and when needed. This helps to ensure the neutral pH of the blood is maintained.

However, the adjustments that the kidney makes to ensure the relevant acid/base is removed can take several days to have an effect. On the other hand, the lungs act much quicker to correct imbalances.

The lungs help to maintain the acid-base balance through the release of carbon dioxide when we breathe. Carbon dioxide is an acidic waste product. The more carbon dioxide present in the blood the more acidic the blood becomes.

The way in which we breathe is controlled by our brain, which can sense the pH of blood. If the pH is too acidic then we will breathe faster and deeper. This allows more carbon dioxide to leave the body and the pH of blood to be corrected efficiently.

4. What happens if acid-base is not controlled?

There are two main disorders of acid-base balance:

• Acidosis: there is too much acid, or too little base, in the blood: pH decreases.
• Alkalosis: there is too much base, or too little acid, in the blood: pH increases.

Metabolic acidosis and metabolic alkalosis occur because of problems with the production of acids or bases and their removal by the kidneys.

Summary

We have described functions of kidney: acid-base balance. We hope it has been useful.

Other resources

Functions of kidneys 1: waste removal
Functions of kidney 2: fluid balance (also affects blood pressure)
Functions of kidneys 4: blood pressure control (makes renin)
Functions of kidneys 5: anaemia, blood cells and EPO (makes erythropoietin)
Functions of kidneys 6: vitamin D activation (activates cholecalciferol)
Functions of kidney 7: making prostaglandins
CKD-related acidosis.

To learn more about acidosis and alkalosis you can watch the following video.

Last Reviewed on 10 March 2024