The heart is a hollow, muscular organ that maintains blood circulation throughout the body. Learn how the circulatory system - your heart, blood vessels and blood - bring nutrients to the body.
The heart is a vital organ that basically serves as a pump. Learn about heart chambers and valves, blood flow, the heart's electrical system and blood supply. Read more about how this amazing organ works. See more »
This detailed medical animation explains the movement of blood between the heart and the body's organs and tissues.
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A vampire is headed straight for you. "I vant to drink your blood," he hisses. To prevent him from sucking the life force straight out of you, you decide to distract him with your amazing knowledge of blood. Take the quiz and prove yourself.
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Every second of the day, blood bustles through your body, bound for your brain, toes and everything in between. How does your heart receive its fair share of the good stuff?
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When you cut yourself accidentally, do you ever wonder what makes up this thing we call blood? It's pretty amazing stuff, considering how it wards off infections while supplying nutrients to every cell in the human body.
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Medical research shows that high levels of cholesterol are associated with heart disease, the nation's number one killer. One in five Americans has high cholesterol -- find out if you're at risk.
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Everything we do is controlled and enabled by electrical signals running through our bodies. But how are those signals produced, and what happens when your electrical system breaks down?
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The natriuretic peptides are sometimes called the body's "natural diuretics" because they lower the concentration of sodium in the blood.
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The heart is a vital organ that basically serves as a pump. Learn about heart chambers and valves, blood flow, the heart's electrical system and blood supply. Read more about how this amazing organ works.
See more »
Lub-dub, lub-dub, lub-dub, that's usually the sound of a happy heart. But what's responsible for that steady, comforting beat, and what if your heart doesn't sound like that?
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When it comes to the heart, timing is critical. An irregular heartbeat is inefficient and deprives the body of blood. So what sets your ticker's rhythm?
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Unless you've been hiding under a giant cheeseburger for the past decade, you probably know that having high cholesterol is bad for you. But it's not all created equal, and knowing the difference will help you to make sense of your cholesterol test.
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Did you know there are eight common blood types? Read our list of blood types to find out which are the most common and which types are compatible.
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Cholesterol produces a wealth of highly valuable substances in the body. It makes its mark in digestion, absorption of vitamins, and even reproduction. Find out why your body needs cholesterol.
See more »We’ve all heard of “good” and “bad” cholesterol, and you may even know which is LDL and which is HDL. It’s important for doctors to know the levels of each. Find out how each type affects your heart and what the levels tell you.
See more »Arrhythmia is the medical term for an irregular heartbeat. In this animation, learn what causes it and how it affects the health of the body.
See more »Smokers are at greater risk of developing artery complications. This animation illustrates the difference between an artery in a smoker and a non-smoker.
See more »Atherosclerosis is caused by fatty material is deposited on the wall of a damaged artery. Watch this animation to learn how it can cause an artery to become blocked.
See more »A blood clot can lodge in an artery in the brain blocking an artery in the brain. This animation illustrates how this happens.
See more »Clotting is the process by which the body heals cut blood vessels. This animation explains how blood clots develop from platelets, clotting factor and fibrin.
See more »One of the heart's most important functions is maintaining normal blood pressure in the body. This animation describes the factors that affect blood pressure and how the heart keeps it steady.
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Learn more about what ails you. Here are some common symptoms.
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