Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.

 

Related Words

Heart: The multicellular, chambered, muscular structure that pumps blood through the circulatory system by alternately contracting and relaxing.

Heart Rate: The number of times your heart beats per minute.

Coronary Heart Disease (Chd): Diseases of the heart muscle and the blood vessels that supply it with oxygen, high risk factor for a heart attack.

Maximum Heart Rate: The maximum number of times your heart should beat in a minute without dangerously overexerting yourself.