Drawing a heart shape may seem easy, but the real heart is a complex organ.
The heart is a cardiac muscle that pumps blood throughout the body. It tirelessly beats roughly 100,000 times throughout the day going mostly unnoticed. No machine is as sophisticated as the heart; without its pumping blood, the rest of the body would not work.
Located slightly to the left side of the chest. The heart is surrounded and protected by the pericardium, which is made of an outer fibrous layer and an inner double layer of serous membrane.
The heart is divided up into a left and right septum. Each side has a small atrium similar to a chamber, above a thick-walled ventricle. The atria and ventricles relax to receive blood from the body, which flows into the ventricles. Then the artria and ventricles contract to push the blood out of the heart to the rest of the body.
A very complex organ, the heart one of the most important muscles for our survival.
[Sources: Walled chart of human anatomy; Oxford dictionaries]