level: The heart
Questions and Answers List
level questions: The heart
| Question | Answer |
|---|---|
| Describe the cardiac cycle | 1) ventricles diastole and atrium systole 2) ventricle systole and atrium diastole 3) ventricle diastole and atrium diastole 4) whole process start again |
| Explain what happens when ventricles relax and atrium contract | - volume decreases and pressure increases in the atrium - this pushes blood into the ventricles through the atrioventricular valves - there's a slight increase in ventricular pressure and volume |
| Explain what happens when ventricles contract and atrium relax | - volume decreases and pressure increases in the ventricles - pressure becomes higher in ventricles than in atria, which forces atrioventricular valves shut to prevent back flow - the high pressure opens the semi lunar valves and blood is forced through the pulmonary artery and aorta |
| Explain what happens when ventricles relax and atrium relax | - the high pressure in the pulmonary artery and aorta causes the semi lunar valves to close - the atria fills with blood due to high pressure in the vena cava and pulmonary vein |
| What is systole | contraction |
| What is diastole | relax |