What Does a Red Blood Cell Do?

As we start this journey of understanding the human body I want to introduce you to the red blood cell. In my opinion it is a foundational powerhouse allowing every part of the body to work.

The red blood cell is what brings oxygen to every part of your body and is the most abundant cell in the blood. It is able to carry oxygen because it contains a protein called hemoglobin. Each hemoglobin can carry 4 molecules of oxygen out to the body’s cells. And each red blood cell has about 270 million hemoglobin (remember how I said it was like a foundational powerhouse for the body?) As if this wasn’t enough, when it gives a cell the oxygen it in turn takes that cell’s waste known as carbon dioxide. It’s basically both your amazon delivery driver and garbage collector all in one (ok, not really but you get the point).

Once your red blood cell has delivered it’s oxygen and picked up the carbon dioxide from the cell, it travels to the lungs. Here the red blood cell does an opposite exchange. It gives your lungs the carbon dioxide so it can be exhaled out of the body and each hemoglobin picks up another 4 molecules of oxygen and goes back out to deliver these to your body’s cells all over again.

The red blood cell is formed in the bone marrow as part of a continual process. It takes 7 days to create a red blood cell and it will work in the body for about 120 days. After this time the red blood cell is no longer able to effectively do it’s job and it is recycled and eliminated by your body.

As your blood is in constant motion throughout your body, it passes through and is filtered by your liver, kidneys and spleen. These organs all play a role in eliminating old and non functioning red blood cells from your body. The body is still very much a mystery and this is one example of that. We still do not completely understand how red blood cells are marked for elimination. One interesting way we know non functioning red blood cells are recognized occurs in the spleen. As your red blood cells pass through the spleen they have to exit the spleen through a special slit. If the red blood cell can pass through the slit then it reenters the bloodstream to keep doing its job. If the red blood cell is no longer able to change its structure to fit through the slit it is recognized as no longer functioning. The spleen contains white blood cells called macrophages that work to break down the old red blood cells so that the worn out parts can be eliminated from the body- and the still useful parts like the iron can be recycled back to the bone marrow to get used to make new red blood cells!

You know that clamp like thing the tech puts on your finger when you go to the doctor? That is called a pulse oximeter and it measures the amount of hemoglobin in your blood that has an oxygen molecule attached to it. According to the American Lung Association a good reading is considered anything over 90-92%. This test does have limitations and is ultimately used as a guide for your healthcare provider to determine if further testing or an intervention such as providing additional oxygen is necessary as they consider the reading in combination with your symptoms.