Test due

the temperature of the mesosphere decreases with altitude because it is heated from below by sunlight

heated from above by the sun

heated from below by the ozone layer

cooled from above by the thermosphere

1. beginning with all chambers of the heart in the "relaxed" phase, describe the cardiac cycle in mammals, with systole and diastole of the atria and ventricles. for each time point in the cycle you select, state the following: • whether the atria and ventricles are contracting or relaxing • whether the av valves and semilunar valves are closed or open • whether the pressure in the atria and ventricles is high or low