Explain why it is important that the heart rate is able to alter?

Your muscles and your brain need a metered amount of oxygen to function properly. As you increase your motion the heartrate picks up speed to move the oxygenated blood through your body to keep up with the energy you are using. The heart gets tiny electrical signals from the brain letting it know how much to increase your heart rate. It is an amazing function of our bodies. Sometimes people have problems because the heart accerates too much or not enough. The problem can be fixed if it is diagnosed properly through minor surgery or medication.