The cardiac cycle

The cardiac cycle:

1)Blood enters the relaxed atria and ventricles from pulmonary veins( from the lungs and vena cava (from the body)

-Deoxygenated blood from the Superior  ( upper body) vena cava and Inferior (lower body) vena cava

-Oxygenated blood comes into the left atrium from pulmonary veins

-atria is filled with blood- high pressure

2) Left and right atrioventricular valves open

3)Atria contract pushing remaining blood into the ventricles (ARTIAL SYSTOLE)

4) Relaxation of the ventricles draws blood…