The first open heart surgery was performed by Dr. Daniel Hall Williams in In a lifetime, the heart pumps about one million barrels of blood. Every day 2,700 people die of heart disease. People say “Bless you” when you sneeze because when you sneeze, your heart stops for a millisecond. The human heart creates enough pressure when it pumps out to the body to squirt blood 30 feet.

Unlike the arteries and veins, capillaries are very thin and fragile. They are so thin that blood cells can only pass through them in single file. Capillaries are involved in the body's release of excess heat.

Coronary artery disease develops when your coronary arteries become damaged or diseased. Exercise and eating right are just a couple of the many ways you can prevent heart disease.

Blood vessels convey blood away from the heart, except for the pulmonary artery, which carries deoxygenated blood from the heart to the lungs. Arteries carry oxygenated blood from the heart to the tissues. Arterial walls expand and contract with each heartbeat, pumping blood throughout the body.

William Harvey was an English physician who was the first to describe correctly and in detail the circulatory system and properties of blood being pumped to the body by the heart.

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