Your heart starts to beat before you are born. It keeps on beating your entire life. What keeps this amazing organ going at such a steady pace?
Your heart is a muscle. But it’s a different kind of muscle than the one in your arm or your leg. A healthy heart muscle doesn’t get tired and it doesn’t need to rest. It is a good thing, too. Your heart has an important job. It pumps blood through your entire body.
A group of special cells inside the heart keep it beating at a regular rate. These cells make up the SA node. The SA node delivers electrical signals to your heart. This sets the pace of your heartbeat. For example, when you exercise, the SA node sends out more signals. This speeds up your heart rate. Then blood moving through your body can deliver oxygen more quickly to the muscles that are working so hard.
When we are scared, special chemicals are released in our body. These chemicals make the SA node fire out more signals. That’s why your heart pounds after a nightmare. In fact, your mouth may get very dry with fear. You are getting a glass of water.
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"What keeps your heart beating?" was posted on Wednesday, August 15th, 2007 at 9:12 pm.