Generally speaking, there is no one “most” important part of the cardiovascular system, since, like other systems in our body, it all works together to function properly. If one piece, such as your heart or arteries, are having issues, the other pieces will follow suit and not function to their full capacity. It’s important to keep your heart and arteries healthy by eating a nutritious, balanced diet, avoiding excessive drinking, smoking or use of drugs, and getting regular exercise. If you have a family history of heart disease or are at an increased risk of experiencing cardiovascular issues, it’s important to be aware of this and have a doctor or specialist that knows your history. With this said, most people understand the cardiovascular system as being the heart itself, and therefore consider it the most important part. It’s true that when we discuss the cardiovascular system, the heart is often mentioned as the central piece, which can be very vulnerable to serious issues.