Missouri University of Science and Technology tuition is $7,734 per year for in-state residents. This is 13% more expensive than the national average public four year tuition of $6,841. The cost is 53% cheaper than the average Missouri tuition of $16,299 for 4 year colleges.
Systole: Period of ejection. AV valves closed Semilunar valves opened AV valves closed Semilunar valves closed Diastole: Period of isovolumic relaxation. Blood flowing back toward the relaxed ventricles causes the semilunar valves to close, which is the beginning of ventricular diastole.
The two atrioventricular (AV) valves are one-way valves that ensure that blood flows from the atria to the ventricles, and not the other way. The two semilunar (SL) valves are present in the arteries leaving the heart; they prevent blood from flowing back into the ventricles.