What is the heart cycle?
The cardiac cycle is a sequence of drawing and filling that occurs from the beginning of the heart rhythm to its destination. The heart is subject to two main events during a complete heart cycle, diastole and systole. During the diastol, the heart is released and filled with blood and blood contraction and blood are pumped. It takes about one second to finish the entire heart cycle. The atrium receives blood from the body to the heart and the chambers are responsible for drawing blood from the heart. The first stage is a systolic or relaxed scene. The right atrium takes deoxygenated blood from the body through the superior and lower vena cava. Because the right hall and the chamber are relaxed and atrioventricular valve between the two chambers is open, blood flows into the right ventricle.
Electrical pulse of sinoatrial (SA) node says atrium on and pushed the remaining blood and signals into burkinjové fibers. The burkinje fibers cause the chamber to withdraw or get into the first phase of the systole in the heart cycle and pump the deoxygenated blood from the after the pulmonary arteryLoselilual valves. The pulmonary artery leads blood to the lungs where it can be reoxygenated.
The oxidized blood returns to the heart through the lung veins and is accepted in the left atrium. The heart is now in the second phase of diastole, so the left atrium is relaxed and the atrioventricular valve is open. Blood passes even if the valve into the left ventricle. The left chamber then gets a message from the burkinje fibers to withdraw or get into the second phase of the systole. These contraction forces open the semilunar valve into the aorta where the blood is pumped into the rest of the body.
Being blood circulates continuously, the heart does not have to wait for the blood to return from the body or from the lungs, so it is constantly filled and pumped. For this reason, one side of the heart is completed at the same time with the fulfillment of the other side and the contraction of one side occurs simultaneously with the contraction of the other. Thus, the first and second phasesThen the first and second phase of the systole occurs. The "Lub-Dup" noise heard when listening to the heart rhythm of the sound. "Lub" is the sound of atrioventricular valves closure and "dup" is the sound of closing the aortic valve.