Final answer:
The blood vessel that lies in the posterior interventricular sulcus and supplies the ventricular walls with oxygenated blood is the posterior interventricular artery, a branch of the right coronary artery.
Step-by-step explanation:
The posterior interventricular artery, which is a branch of the right coronary artery, lies in the posterior interventricular sulcus and supplies the walls of the ventricles with oxygenated blood. This artery is also known as the posterior descending artery and runs along the posterior portion of the interventricular sulcus toward the apex of the heart, giving rise to branches that supply the interventricular septum and portions of both ventricles.
The circulation of blood delivered by this artery reflects the critical role of coronary arteries in providing a reliable supply of oxygen and nutrients to the heart muscles (myocardium). The coronary veins that run parallel to this artery help in draining the heart by carrying deoxygenated blood away from the myocardium.