Oxygen, nutrient, waste, etc transportation around the body.
Check out the Circulatory system
To pump your blood
pump the blood throw the body
A: to pump the blood around our body
you need the fluid from water to pump blood through your body
they need the heart to pump them
No the heart pumps the blood but it does pump the blood through the arteries.
The atria does not need to be very thick because all it needs to do is fill up with blood so that the ventricles can pump out the blood. The ventricular walls are thick so that they can properly pump out blood to the needed areas.
The ventricles contract to pump blood out of the heart.
Actually, if you think about it the job of a heart is to pump blood throughout the body, the constant need of pumping this blood requires the strength and endurance to continuously pump without end, thus you can only imagine the need for strong muscles a heart may have.
pump blood you a******
the atria only pump blood to the ventricles
the atria pump blood only to the ventricles.