The Cardiac Cycle Flashcards
Describe the five stages of the cardiac cycle
- Late diastole
- Atrial Systole
- Isovolumetric ventricular contration
- Ventricular ejection
- Isovolumetric ventricular relaxation
What happens during late systole?
Both sets of chambers are relaxed and ventricles fill passively
Whats happens during atrial systole?
Atrial contraction forces a small amount of blood into the ventricles
Whats happens during isovolumetric ventricular contraction?
Contraction - first phase of ventricular contraction pushes AV valves closed but does not create enough pressure to open semi-lunar valves
Whats happens during ventricular ejection?
As ventricular pressure increases and exceeds pressure in the arteries, the semi-lunar valves open and blood is ejected
Whats happens during isovolumetric relaxation?
As ventricles relax, pressure in ventricles decreases, blood flows back into the cusps of the semi-lunar valves and snaps them closed
Stenosis of the aortic/pulmonary valves would create a murmur at what point in a normal heart phonocardiogram?
In-between S1 (mitral and tricuspid closure) and S2 (aortic and pulmonary closure)
What other pathology would create a similar sound to aortic/pulmonary stenosis?
Mitral/tricuspid regurgitation
Stenosis of the mitral and tricuspid valves would cause a murmur at what point in an otherwise normal phonocardiogram?
After S2 (aortic and pulmonary closure)
What other pathology would create a similar sound to mitral/tricuspid stenosis?
Regurgitation through aortic and pulmonary valves
What pathology would create a constant whooshing sound?
Septal defect