Now what about valve number two? So valve number two is this valve here. It basically connects the right ventricle to these pulmonary arteries. So this is known as the pulmonary semi lunar valve or simply the pulmonary valve. Now when the ventricle when the right ventricle actually relaxes, blood flows from this location to this right ventricle. But at the same time that this valve number one is open, valve number two, the pulmonary valve has to be closed because we don't want a backflow of blood from the pulmonary arteries back into the right ventricle.