The cardiac cycle Flashcards
Define the cardiac cycle
The process of cardiac contraction and blood transportation through the heart.
Define diastole
The phase of the cardiac cycle that sees the heart relax and fill with blood.
Define systole
The phase of the cardiac cycle when the heart contracts.
What happens during systole?
Blood is ejected from the heart or forced from one chamber of the heart to another.
What happens during atrial diastole?
The upper chambers of the heart fill with blood. Either from the vana carvae or the pulmonary vein.
In what direction does blood always move?
From an area of high pressure to an area of low pressure.
As the atria fill with blood the atria pressure increases. What does this cause to happen?
The atrioventricular valves to open allowing blood to flow into the ventricles.
What happens during ventricular diastole?
The ventricles fill with blood from the atria which are under a high amount of pressure.
During Ventricular diastole what is happening to the semilunar valves?
They are shut.
When the atria contract what does this force?
All remaining blood in the atria to fall into the ventricles.
When the blood flows from the atria into the ventricles the pressure in the ventricles increase. What does this cause?
The atrioventricular valves to shut.
When the ventricular pressure overcomes that in the aorta and the pulmonary artery what happens?
The semilunar valves open and the ventricles contract.
What happens when the ventricles contract?
All blood remaining in the ventricles is forced up into the pulmonary artery and the aorta.
