Cardiac Cycle

Question 1

Diastole in three steps, plus critical 4th step before contraction

Answer 1

1) rapid refilling: 80% of blood through atria to the ventricles in the first 1/3 of diastole
2) small amount of blood continues to flow in
3) atria contract to push an additional 20% of the blood into the ventricle
4) (not part of diastole) Ventricles contract; AV valve closes, but semilunar valves remain closed for .02-.03 seconds before pressure opens it, forcing blood out of ventricles andinto the arteries

Question 2

When can we measure isometric volume?

Answer 2

During isometric contraction: when AV valves close but semilunar valves haven’t open for .02 to .03 seconds.

Also occurs when semilunar valves close, while it takes a second for the AV valves to open

Question 3

Rapid ejection (specific pressure in ventricles)

Answer 3

rapid ejection occurs when the left ventricle hits around 80 mmHG and the right ventricle is about