Chapter Review. The cardiac cycle comprises a complete relaxation and contraction of both the atria and ventricles, and lasts approximately 0.8 seconds. Beginning with all chambers in diastole, blood flows passively from the veins into the atria and past the atrioventricular valves into the ventricles.
What are the 5 stages of the cardiac cycle?
5 Phases of the Cardiac Cycle
- Atrial Systole.
- Early Ventricular Systole.
- Ventricular Systole.
- Early Ventricular Diastole.
- Late Ventricular Diastole.
What are the 6 phases of the cardiac cycle?
Detailed descriptions of each phase can be obtained by clicking on each of the seven phases listed below.
- Phase 1 – Atrial Contraction.
- Phase 2 – Isovolumetric Contraction.
- Phase 3 – Rapid Ejection.
- Phase 4 – Reduced Ejection.
- Phase 5 – Isovolumetric Relaxation.
- Phase 6 – Rapid Filling.
- Phase 7 – Reduced Filling.
What are the 8 steps of the cardiac cycle?
Terms in this set (8)
- Atrial systole. atrial contraction begins. …
- Atria eject blood into ventricles. filling of ventricles.
- Atrial systole ends. AV valves close. …
- Ventricular systole. …
- Ventricular ejection. …
- Ventricular pressure falls. …
- Ventricular diastole. …
- Atrial pressure is higher than ventricular one.
What are the 3 phases of cardiac cycle?
Every single heartbeat includes three major stages: atrial systole, ventricular systole, and complete cardiac diastole. Atrial systole is the contraction of the atria that causes ventricular filling.
What are the 4 phases of diastole?
The four components of diastole include (1) isovolumic relaxation period (2) rapid filling (3) slow filling (4) atrial systole. However, factor that influence normal diastolic function also include myocardial relaxation or compliance, elastic recoil, passive ventricular filling, atrial function, and HR .
What regulates cardiac cycle?
Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines – epinephrine and norepinephrine) to accelerate the heart rate.
When are all 4 heart valves closed?
All Valves Closed
When the intraventricular pressures fall sufficiently at the end of phase 4, the aortic and pulmonic valves abruptly close (aortic precedes pulmonic) causing the second heart sound (S2) and the beginning of isovolumetric relaxation.