What does the above image show? It could be any of a number of things. A bowl of melted strawberry ice cream. Some chewed bubble gum. But the above image is actually a close-up of cardiac muscle, the muscle that makes up your heart. If you recall, cardiac muscle is one of three muscle types in the human body. Is cardiac muscle found anywhere else in the body? No. Cardiac muscle is only found in the heart!

Why is cardiac muscle only found in the heart? Why does the heart need its own special muscle? What does blood do, anyway? If a heart pumps blood, how does the heart get the blood it needs to keep pumping? What happens if the heart does not get enough blood?

You may have heard of a heart attack - but what is actually happening in the heart when that happens?

Consider these questions about the heart and cardiac muscle as you read about one of the most important and intriguing systems in the body, the cardiovascular system.