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.
The heart pumps blood around the body through the blood vessels. Blood pressure is the amount of force exerted on the artery walls by the pumping blood. High blood pressure (hypertension) means that your blood is pumping with more force than normal through your arteries. The added stress on the arteries can speed up the clogging of arteries with fatty plaques (atherosclerosis). Atherosclerosis contributes to many illnesses, such as heart attack and stroke.