Tachycardia is a condition when the heart rate is greater than 100 beats per min at rest. The electrocardiogram is a diagnostic tool that measures and records the electrical activity of the heart. Bradycardia on the other hand is when the heart rate is slower than normal. The Tachycardia and bradycardia can arise from either the SA node or from other areas of the cardiac.
B. Depth creates the overall weight and more something is to be measured
Hormones -- such as melatonin and cortisol; the former signals the body to go to bed, while the latter signals for the sleeping person to wake up -- are created by physiological changes.
