only they know
The atrioventricular valves.
atriums and ventricles are apart of the four parts of your heart ventricles are on the bottom and atrium's are on the top hope this helped =D
some does like the atriums and the ventricles
left and right atriums left and right ventricles
It is the door/opening between the ventricles and atriums.
The atriums squeeze to push blood to the ventricles, and the ventricles push the blood to separate parts the body.
4 2 ventricles and 2 atriums.
Heart
There are no valves between the atria. The valves between the atria and ventricles close when the ventricles contract.
4; the right and left ventricles and the right and left atriums.
In the heart of a mamal there are only two ventricles and two atriums (atria).
-the atriums are smaller then the ventricles. -the atriums have thinner muscle tissue. -the atriums only have to pump blod to the ventricles. -the ventricles are larger in size. -the ventricles have larger muscle tissue. -the ventricles have to pump blood to either the lungs or around to the rest of the body. hope this helpedddd ;D xox <3 Bellaaaa