Pick three factors that can change your heart rate. How do they change your heart rate? (i.e. faster, stronger, slower, weaker) For each give another system affected by the change in heart rate.

Things that affect your heart rate could be due to caffeine, or adrenaline, or exercise. These factors increase heart rate. Exercising will cause your heart beat faster because of the lack of oxygen. The change in heart rate affects your respiratory system because the faster your heart pumps the more your respiratory works to meet the demand for oxygen that the body needs.