About Your Heart
Here's a quick-and-easy breakdown of the heart and vascular system and how it works.
The Circulatory System
A healthy heart beats approximately 100,000 times a day, pumping some 2,000 gallons of blood through the circulatory system, which includes the heart, arteries, arterioles, vessels, veins and lungs. That blood dissemination delivers oxygen and nutrients to all parts of the body and also serves as a garbage disposal of sorts, collecting, removing and filtering waste products.
Located between the lungs, the heart is composed of four chambers (two to a side) - the atria, upper chambers that collect blood entering the heart, and the ventricles, lower chambers that pump blood into the body. In addition to chambers (think of them as rooms), the heart has four valves (think of them as doors), which regulate blood flow into the arteries and veins, a system that's more than 50,000 miles long in every one of us.
The arteries, known as pulmonary, coronary and aorta, are the vessels by which blood travels in and out of the heart. Pulmonary veins carry blood from the lungs to the heart to be shared with the rest of the body, and the vena cava (superior and inferior) carries blood from the body to the heart for oxygen rejuvenation.
How Your Heart Works
The miracle of the beating heart commences through an electrical impulse, which causes a chamber contraction and blood to flow. The valves prevent blood from flowing backward.
The contractions require that the heart's left and right sides work together as blood is delivered from the atria to the ventricles, which then release blood to the body; the familiar "lub-dub, lub-dub" sound comes when the heart rests before refilling with blood to start the next beat.
The average weight of a heart is about 10 ounces, a fraction of the weight of a human body. A person's pulse rate (average heart rate per minute) changes over their lifetime, beating as many as 120 times a minute as a newborn and as little as 60 as an adult. In a 70-year lifetime, the heart will beat in excess of 2.5 billion times.
Heart and Vascular Conditions
Common conditions that affect the heart and vascular system include: