Heart

Heart is about the size of its owner's clenched fist, located almost in the center of the chest, between the lungs, it made up of cardiac muscle that works involuntarily and divided into four parts called chambers, these chambers are hollow inside. The two chambers on top are called Atrium and chambers on the bottom are called Ventricles. Your heart also has four valves that let blood in and out of the chambers. Tubes called Arteries come out of your heart and tubes called Veins go into your heart.

Heart weighs approximately 250 to 300 grams in females and 300 to 350 grams in males. Normally the heart contracts and relaxes between 70 and 80 times per minute, each heartbeat filling the four chambers inside with a fresh round of blood, it beats 100,000 times every day, approximately 2.5 billion times during an average 66 year lifespan. Heart pump approximately 8,000 liter of blood a day which travel 60,000 miles through your blood vessel that feed your organ and tissues.