Share. By Alison Doyle. According to the Bureau of Labor Statistics, the median wage for workers in the United States at the end of September 2014 was $790 per week or $41,080 per year for a 40 hour work week. Wages were 2.5% higher than at the same date for the previous year.
Normal. The two major sounds heard in the normal heart sound like âlub dubâ. The â lubâ is the first heart sound, commonly termed S1, and is caused by turbulence caused by the closure of mitral and tricuspid valves at the start of systole. The second sound,â dubâ or S2, is caused by the closure of aortic and pulmonic valves, marking the end of systole.
1. Explain why ventricular contraction (systole) and the 'lub' sound occur immediately after the QRS complex. The lub sound occurs during the beginning stages of systole (ventricular contraction) and when the atrioventricular valves, which prevents blood from flowing back into the atria. The QRS complex is the first heart beat of the cycle, so directly after the heart beat or QRS complex, the valves close to prevent backflow and makes the âlubâ sound. 2. Explain why ventricular relaxation (diastole) and the 'dup' sound occur after the T wave. The T wave is the wave produced by the relaxation of the ventricles, which causes the blood pressure to drop and when the semilunar valves close, the âdupâ sound is made. 3.