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.
For example, the neuron-neuron contact is called a neuronal synapse. while the neuron-skeletal muscle cell contact is called a neuromuscular or myoneural junction. The contacts made by nerve cells with cardiac muscle, smooth muscle, and gland cells are all neuroeffector junctions.