Quote Originally Posted by **ShadowZone**
I don’t understand how you can see your heart beating. (?) Aren’t there things in front of it to protect it from any damage like your lungs and ribs and skin?

Quote Originally Posted by withered
Other than skin and the sternum, there isn't much in the way.
To elaborate, your heart is behind the sternum in a cavity called the mediastinum. The sternum is your breastbone in layman’s terms and that is your protection from your heart. Oh and your pericardium but that doesn't do much if you get a spear through the chest.
The heart is not behind your lungs, it is beside them. That is why your left lung is slightly smaller; because the heart is slightly more too the left, though as a whole it is quite near the centre of your body.