This sound is produced by the closure of the semilunar valves —the aortic and pulmonary valves.
The "lub" marks the beginning of systole, while the "dub" marks the beginning of diastole.
The ventricles have finished squeezing and are beginning to relax so they can refill with blood.
This sound is produced by the closure of the semilunar valves —the aortic and pulmonary valves.
The "lub" marks the beginning of systole, while the "dub" marks the beginning of diastole. what is the lub dub sound
The ventricles have finished squeezing and are beginning to relax so they can refill with blood. This sound is produced by the closure of