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.
During aerobic, upright exercise, such as walking, people will experience an increase in systolic blood pressure and a slight decrease in diastolic blood pressure. Systolic blood pressure increases to improve blood flow, which is necessary to provide higher levels of oxygen to working muscles.lood pressure readings consider two numbers: systolic and diastolic pressure. Systolic blood pressure is the pressure in the arteries when the heart beats, while diastolic blood pressure is the pressure in the arteries between heartbeats when the heart is resting and refilling with blood.