The Cardiac Cycle Flashcards
What is the name of the first stage of the cardiac cycle, where both sets of chambers are relaxed?
Late Diastole (the ventricles fill passively)
What is the name of the stage that follows late diastole in the cardiac cycle and what occurs at this stage ?
Atrial systole: The atria contract pushing an additional small amount of blood into the ventricles.
What is the name of the stage where ventricular contraction first occurs ?
Isometric ventricular contraction
What occurs in the heart during the isovolumic ventricular contraction phase ?
There is now enough pressure in the ventricles to close the tricuspid & mitral valves but not enough pressure to open the pulmonary & aortic (semi-lunar) valves.
After isovolumic ventricular contraction what occurs in the heart ?
Ventricular ejection. The pressure in the ventricles is now high enough to open the semi-lunar valves & blood is ejected through these valves.
The final stage of the cardiac cycle is known as isovolumic ventricular relaxation, what occurs in this phase ?
As the ventricles relax the pressure inside the ventricles drops. The blood flows back towards the semi-lunar valves causing them to close.
Name the stages 1-5 in the cardiac cycle
1: late Diastole
2: Atrial systole (atrial contraction)
3: Isovolumic Ventricular contraction
4: Ventricular ejection
5: Isovolumic ventricular relaxation
How is pulse pressure calculated ?
The difference between Systolic & Diastolic pressures
How is stroke volume calculated ?
End Diastolic Volume (EDV) - End Systolic Volume (ESV)
There are 2 main heart sounds that can be heard, what does the first heart sound signify ?
The closing of the Mitral & valves closing ?
What does the second heart sound signify ?
The Aortic & Pulmonary valves closing
Where in relation to heart sound 1 & 2 would a stenosis of the aortic or pulmonary valves be heard ?
Between sound 1 & 2 (between lub dub)
Where in relation to heart sound 1 & 2 would regurgitation through the AV valves be heard ?
Between sounds 1 & 2 (between lub dub)
Where in relation to heart sound sound 1 &2 would a stenosis of the AV valves be heard ?
After sound 2 (after dub)
Where in relation to heart sound 1 & 2 would regurgitation through the Aortic & Pulmonary valves be heard ?
After sound 2 (after dub)
