Heart & coronary arteries
Cor, Arteriae coronariae
// Structure & location
The heart is a hollow muscle about the size of a fist, sitting slightly to the left behind the sternum. It has four chambers: two atria and two ventricles. The right and left coronary arteries arise right at the start of the aorta. They encircle the heart like a crown, hence the name, and branch into the heart muscle.
// Function
The right side of the heart pumps blood to the lungs, the left side to the body. The coronary arteries supply the constantly working heart muscle with oxygen. They fill mainly during the heart's relaxation phase, when the muscle isn't squeezing them.
// For training & sport
- Endurance training makes the heart larger and stronger, so it pumps more blood per beat. That's why resting heart rate drops.
- Regular exercise is one of the most important protective factors against narrowing of the coronary arteries.
// Good to know
If the coronary arteries narrow, a feeling of tightness in the chest can appear during exertion. If one suddenly closes, that is a heart attack and an emergency.