When blood moves from an atrium to a ventricle what happens?
The blood is then pumped from the ventricle through the a valve into the arteries.
The heart is a double, double pump. The heart pumps the blood down from the atrium into the ventricle. The second pump pushes the blood out of the ventricle into the arteries.
This double pumping occurs on both the left and right sides of the heart. The valves must open to allow the blood out of the atrium into the ventricle and close the valve on the ventricle on the first pump. Then the valve between the atrium and ventricle closes and the valve between the ventricle and the arteries opens so when the heart pumps again the blood is pushed out of the ventricle into the artery.