ERA. 1  baseball, baseball game - a ball game played with a bat and ball between two teams of nine players; teams take turns at bat trying to score runs; he played baseball in high school; there was a baseball game on every empty lot; there was a desire for National League ball in the area; play ball!.
The contraction of the heart muscle starts in the two atria, which push the blood into the ventricles. Then the walls of the ventricles squeeze together and force the blood out into the arteries: the aorta to the body and the pulmonary artery to the lungs.
As the muscles contract, they squeeze the veins and force the blood upward to your heart. What prevents the blood from being forced back down is a series of one-way valves inside the veins; when functioning properly, these valves permit blood flow only in the right direction. FLAVONOIDS CAN SPELL RELIEF.