Your heart is located between your lungs in the middle of your chest, behind and slightly to the left of your breastbone. A double-layered membrane called the pericardium surrounds your heart like a sac. The heart weighs between 7 and 15 ounces (200 to 425 grams) and is a little larger than the size of your fist.
The myocardium is the muscular wall of the heart, or the heart muscle. It contracts to pump blood out of...
Your heart is made of muscle, called the myocardium. The heart muscle, like every other organ or tissue in your...
Electrical impulses in your heart muscle (the myocardium) cause your heart to beat (contract). This electrical signal begins in the...
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