Annual deaths from tornadoes, earthquakes and floods together total fewer than 200. The most deadly heat wave in recent years occurred in Chicago over a week in July 1995, when temperatures hovered around 100 degrees.
Cardiac Cycle: 1st Systole Phase. During the systole phase, the right ventricle receives impulses from the Purkinje fibers and contracts. The atrioventricular valves close and the semilunar valves open. The de-oxygenated blood is pumped into the pulmonary artery.
Period of ejection (systole) 3.Isovolumic relaxation (diastole) 4. Passive ventricular filling (diastole) 5. Active ventricular filling (diastole) ***The cardiac cycle only focuses on events occurring in the ventricles, NOT atria).