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.
Blood clots are essential to stop bleeding after injury, but harmful blood clots can also form, causing serious damage. Most heart attacks and strokes result from the sudden formation of a blood clot on a cholesterol plaque inside an artery in the heart or brain. When the plaque ruptures suddenly, thrombogenic substances inside the plaque are exposed to blood, triggering the blood clotting process.