Instructor: Debbie Notari. Understanding a story's theme is critical to deciphering an author's message in a particular piece of writing. In this lesson, we will examine the idea of theme and look at some examples in actual literary works.
Location: The coronary system is comprised of arteries, arterioles, capillaries, venules and veins. The coronary arteries originate as the right and left main coronary arteries which exit the ascending aorta just above the aortic valve (coronary ostia).These two branches subdivide and course over the surface of the heart (epicardium) as they traverse away from the aorta.ocation: The coronary system is comprised of arteries, arterioles, capillaries, venules and veins. The coronary arteries originate as the right and left main coronary arteries which exit the ascending aorta just above the aortic valve (coronary ostia).
The left main coronary artery (LMCA) arises from the left aortic sinus, running towards the left hand side of the heart, just below the left auricle. It quickly divides into the anterior interventricular branch also known as the left anterior descending (LAD) artery and the circumflex artery.The LAD runs along the anterior interventricular sulcus, a groove in the anterior surface of the heart that seperates the left and right ventricle, down towards the apex.rom here, it curls around towards the inferior surface of the heart, forming the posterior interventricular branch, more commonly known as the posterior descending artery (PDA). The PDA runs along the posterior interventiculas sulcus, to supply blood to the walls of both the left and right ventricle.