The coronary veins and arteries are the blood vessels responsible for supplying blood to the heart muscle (myocardium), ensuring that the heart receives enough oxygen and nutrients to function properly. The coronary arteries originate from the aorta, the largest blood vessel in the body, right after it exits the heart, and deliver oxygen-rich blood directly to the cardiac tissue. There are two main coronary arteries: the left coronary artery and the right coronary artery, which branch into smaller vessels to cover the entire extent of the heart.

The left coronary artery divides into two main branches: the left anterior descending artery (LAD), which runs along the front of the heart, and the circumflex artery, which supplies blood to the lateral and posterior parts of the heart. The right coronary artery runs along the back of the heart, irrigating the right side of the organ.

The coronary veins collect oxygen-depleted blood after it has passed through the heart tissues. The main coronary veins connect to the coronary sinus, a large vein located at the back of the heart, which drains blood back into the right atrium, where it is sent to the lungs to be reoxygenated. Any obstruction in the coronary arteries can reduce blood flow to the heart muscle, leading to issues such as coronary artery disease, which can cause angina (chest pain) or, in severe cases, myocardial infarction (heart attack).