The heart, is a vital  organ inside of you. Your body, depends on it all the time. without the heart we would not be here today. The heart is about the size of you fist  clenched. Also the heart beats 100,000 and the heart beats 2.5 billion times a lifetime. The heart is located in your chest on the left of you sternum. When you grow your heart grows because when you grow your heart needs to work twice as you grow. Your veins  grow as you grow up  so you heart needs to grow as you do as your veins develop. Your blood  takes  nutrients around your body.

First, your blood contains blood cells that go to the lungs and take oxygen from them to give it to the heart your blood must have oxygen .The oxygen stick to the blood cells and the blood cells then take it back to the heart. When blood cells have got all the oxygen they then take it to the left atrium and than to the right atrium.  The blood cells are bumped all around the body this is why you can hear and feel your heart bet. If there was no oxygen (which is on the lungs)the system would not work probably..  The heart never stops and always  beats  every day. This whole process happens in the time it takes you to blink.

Some extra facts 

The heart is one of the most hard working thing inside of your body. Your heart does this over 100,000 times a day.