PUBLISHED: 4:50 PM on Wednesday, June 13, 2007
Hey kids: What's up with that heart?
Have you ever crossed your heart when you really meant a promise you made? On Valentine's Day, did you give heart shaped valentine to your friends? How many of us have heard mom and dad tell us that there is a special place for us in their heart? And on the radio, there's always a song about someone's broken heart.

A long time ago, it was thought that our emotions came from our heart because when a person is scared or excited the heart beats faster. That's because our brain tells our heart to speed up, so we can be ready to run if we need to.

So, what's up with the heart? The heart is a muscle that sits a little to the left in the middle of your chest and is about the size of a fist.

Now we have several other muscles in our body but this one is special because it sends blood around our body and the blood provides our body with oxygen and the nutrients it needs; it also carries away those things we don't want.

The heart is like a double sided pump, the right side of the heart receives blood from the body and sends it to the lungs, and the left side receives blood from the lungs and pumps it into the body. Wow, a lot of pumping of blood but that blood is what gives our heart the beat.

So how does the heart beat? Before the heart can beat it fills with blood. The heart then contracts to move the blood along. Here's an example, make a fist and squeeze then let go and squeeze again. That's what our heart is doing all day and night with no time outs: now that's a hard working heart!

Your heart is made up of four areas, and these are called chambers. There are two chambers on each side of the heart; one on the bottom and one on top. The two chambers on top are called the atria and they are filled with the blood returning from the body and the lungs.

The chambers on the bottom are called the ventricles and their job is to pump out the blood to the body and the lungs. The area that runs directly down the center of our heart is called the septum and separates the left side from the right side of the heart.

How does the blood know where to go after getting pumped? Well, it relies on four special valves inside the heart. A valve lets something in and keeps it there by closing, ike a door. You come in a door and the door closes to prevent you from going backward.

Two of the valves are called the mitral and the tricuspid, their job is to let blood flow from the atria to the ventricles. The other two valves are called the aortic and pulmonary valves and they control just how fast the blood leaves the heart to the body. So all these valves work as a team by opening to help our blood move forward and then closing quickly to prevent it from flowing backwards.

Once the blood leaves the heart it jumps on board the blood vessel express and travel's through tubes that we call arteries and veins. Arteries carry the blood away from our heart and veins carry the blood back to the heart and all of this is called circulation.

Our heart is awesome at this, in fact it only takes 60 seconds for our heart to pump blood to every cell in our body.

Now the oxygen in our blood is taken by our body and used in our cells, and when our cells use the oxygen they make carbon dioxide that is carried away by the blood.

I guess you could say that the blood serves breakfast to the cells and then picks up the trash afterwards.

So next time you hear a song on the radio, cross your heart or even give a heart shaped Valentine, remember that your heart is the center of your universe, and body, so treat it with lots of love by exercising and eating right and it will continue to pump for your entire life.

The American Red Cross of Alaska would like to invite parents and children to the Heart Matters class from 1-2 p.m. Monday, June 18. Come and learn how to develop a heart healthy plan to reduce your risk of heart disease. To register, call the offices at 463-5713.