What are the functions of the atria and ventricles in the heart?

The function of the atria is to collect and pump blood into the ventricles. The function of the ventricles is to pump blood into systemic and pulmonary circulations.

A heart has 4 chambers- two atria and two ventricles.

The right atrium receives oxygen-poor blood from your body and then it pumps all of that to the right ventricle.

The right ventricle pumps your oxygen-poor blood to your lungs.

The left atrium receives oxygen-rich blood from your lungs and then pumps it to your left ventricle.

Hope that helps:)

Blood transfusions were rarely done and often fatal; they were outlawed until the nineteenth century.