fig1

Figure 1. Structure of the coronary vasculature. Coronary arteries are comprised of an inner endothelial cell lining (intima), internal elastic lamina, multiple layers of smooth muscle cells (media), external elastic lamina and an outer adventitia comprised of fibroblasts and connective tissue. Coronary arteries branch into pre-arterioles and arterioles which are much smaller. Whilst they retain the triple layering (intima, media and adventitia) and internal elastic lamina, the external elastic lamina is lost and the medial and adventitial layers are much thinner.