Right coronary artery

Where does the right coronary artery run?

It arises from an aortic sinus just above the aortic valve and follows the right side of the coronary sulcus, the groove between the atria and the ventricles. (OpenStax A&P 2e, 19.1; StatPearls, Heart Arteries)

It continues round to the back of the heart. At the crux cordis it gives off the posterior interventricular artery and the right posterolateral artery. (StatPearls, Heart Arteries)

What are the branches of the right coronary artery?

Its first branches are the conus artery, to the infundibulum of the right ventricle where the pulmonary trunk arises, and, in many hearts, the branch to the sinoatrial node. (StatPearls, Heart Arteries and Heart and Pericardial Cavity; OpenStax A&P 2e, 19.1)

Along the coronary sulcus it gives off the right marginal artery, which runs along the acute margin, the lower front border of the heart. (StatPearls, Heart Arteries)

At the end of its course, on the diaphragmatic surface, it gives the branch that supplies the atrioventricular node. (StatPearls, Heart Arteries)

What does the right coronary artery supply?

It supplies the front and diaphragmatic surfaces of the right atrium and the right ventricle. (StatPearls, Heart Arteries)

In most hearts it also reaches the interventricular septum and parts of both ventricles, through its posterior interventricular branch. Septal branches of that artery supply the back third of the septum. (OpenStax A&P 2e, 19.1; StatPearls, Heart Arteries and Heart and Pericardial Cavity)

Where does the right coronary artery meet other vessels?

It joins the circumflex artery of the left coronary artery in the coronary sulcus. Its posterior interventricular branch joins branches of the anterior interventricular artery. (StatPearls, Heart Arteries; OpenStax A&P 2e, 19.1)

The small cardiac vein runs beside it and drains the back of the right atrium and the right ventricle. (OpenStax A&P 2e, 19.1; Gray 1918, 3. The Systemic Veins; StatPearls, Heart Veins)

Does the right coronary artery vary?

In most hearts it gives rise to the posterior interventricular artery, which makes the heart right dominant. The StatPearls article on the heart arteries puts that share at 70% or more, and the article on cardiac muscle at 85%. (StatPearls, Heart Arteries and Cardiac Muscle)

The conus branch can leave the aorta through an opening of its own, apart from the right coronary artery. (StatPearls, Heart Arteries)

Where the sources differ

The sources differ on which artery supplies the sinoatrial node. The StatPearls article on the heart arteries lists the sinoatrial branch among the first two branches of the right coronary artery, and the article on the heart and pericardial cavity says the right coronary artery often supplies the node. The article on cardiac muscle lists the node among the parts the circumflex artery supplies. (StatPearls, Heart Arteries, Heart and Pericardial Cavity and Cardiac Muscle)

The StatPearls article on the heart arteries gives two shares of the interventricular septum for this artery: the back two thirds where it describes the artery, and the back third where it describes the septal branches of the posterior descending artery. The StatPearls article on the anterior descending artery gives that artery the front two thirds. (StatPearls, Heart Arteries and Heart Left Anterior Descending Artery)