Final answer:
The coronary vessels run along the epicardium, which is the outer layer of the heart wall. The endocardium covers the heart valves and the myocardium is the muscle layer responsible for the heart's beating. The blood flowing through the mitral valve is oxygenated, as it goes from the lungs to the rest of the body.
Step-by-step explanation:
The coronary vessels, specifically the coronary arteries and veins, run along the epicardium, which is the outermost layer of the heart wall and is also the innermost layer of the pericardium. The coronary vessels form a ring-like structure around the heart which then divides into branches that supply blood to the heart tissues. These vessels are crucial for delivering oxygenated blood to the myocardium, the muscle layer responsible for the beating of the heart.
Answering the initial question, the coronary vessels run along the epicardium (option c). Given the descriptions provided:
- The endocardium covers the heart valves and lines the chambers where blood circulates.
- The myocardium is the thick muscle layer responsible for the beating of the heart.
- The pericardium surrounds and protects the heart.
As for the blood flowing through the mitral valve, it is oxygenated because the mitral valve is located between the left atrium and the left ventricle, and the left side of the heart handles oxygenated blood that has returned from the lungs and is to be distributed to the body.