Hypothesis: When recording the electrocardiogram for each subject, we expect to see normal sinus rhythm between P wave, QRS waves, and T waves. P waves should be succeeded by QRS waves and then finally T waves. We expect to see the P waves have the lowest amplitude, R waves the highest amplitude, and T waves amplitude lies in-between the two. Secondly, the second heart sound, or “dub”, will last longer than the first heart …show more content…
Atrioventricular valves, or AV valves, are located between the atria and ventricles. Between the right atrium and right ventricle, the tricuspid valves exist; and the mitral valve separates the left atrium and left ventricle. Chordae Tendineae, which are attached to the AV valves and anchored to the papillary muscles, allow one-way flow by preventing eversion of the valves. Semilunar valves separate the ventricles from the arterial system. The aortic valve separates the left ventricle from the aorta while the pulmonary valve divides the right ventricle and pulmonary artery. AV valves and semilunar valves perform an important role in the cardiac cycle because they only allow blood flow when pressure gradient is reached. During ventricular filling, the AV valve remains open due to atrial pressure being higher then ventricular pressure. Concurrently, the semilunar valves are closed as a result of higher pressure in outflow tract then ventricle. When ventricular pressure surpasses atrial pressure, the AV valves close, indicating the isovolumetric ventricular contraction. This period of ventricular contraction is also called systole. Once ventricular pressure eclipses pressure of outflow tract, the semilunar valves open, allowing an outpour of blood into the pulmonary or systemic systems. Lastly, isovolumetric ventricular relaxation is reached. The muscle relaxes, semilunar valves closes, and pressure in ventricular falls until it is less the atrial pressure, which initiates the opening of the AV valves. This period or relaxation is known as