Describe The Relationship Between The Two Phases Diastole And Systole

The cycle of cardiac activity is split into two phases, diastole and systole. Diastole shows the period in time when the ventricles are relaxed. In this time the blood is passively going from the left atrium and right atrium into the left ventricle and right ventricle. Blood flows through mitral and tricuspid atrioventricular valves these separate the atria from the ventricles. The right atrium receives blood from the body through the superior vena cava and inferior vena cava. The left atrium receives oxygenated blood from lungs through four pulmonary veins that enter the left atrium. At the end of diastole, both atria contract, which drives an additional amount of blood into the ventricles.
Systole signifies the time during which the left
It is initiated by the P wave of the electrocardiogram. Atrial depolarization starts contraction of the cardiac muscle. When the atria contract, pressure within the atrial chambers increase, this forces more blood flow across the open atrioventricular valves, leading to a rapid flow of blood into the ventricles. Directional flow to vena cava is restricted to one way flow as the wave of contraction through the atria moves toward the atrioventricular valve. 10% of left ventricular filling is when a person is at rest. This is because most of ventricular filling happens previous to atrial contraction as blood passively goes from the pulmonary veins to the left atrium from there it goes into the left ventricle through the open mitral valve. The T wave represents the recovery of the ventricles. The break from the beginning of the QRS complex to the peak of the T wave is referred to as the ‘absolute refractory period’. The last half of the T wave is referred to as the ‘vulnerable period’.
When atrial contraction is complete the atrial pressure will fall. This causes a pressure gradient reversal across the AV valves. At this time, the ventricular volumes are greatest, which is called the end-diastolic volume. A heart sound is sometimes heard during atrial contraction (S4). This sound is caused by the vibration of the ventricular wall during atrial contraction. It is noted when the ventricle compliance is
Blood is ejected because the total energy of the blood within the ventricle exceeds the total energy of blood within the aorta. During this phase, ventricular pressure normally exceeds outflow tract pressure. This pressure gradient across the valve is ordinarily low because of the relatively large valve opening. No heart sounds are ordinarily noted during ejection because the opening of healthy valves is silent. Left atrial pressure initially decreases as the atrial base is pulled downward, expanding the atrial chamber. Blood continues to flow into the atria from their respective venous inflow tracts and the atrial pressures begin to