"The typical configuration consists of two coronary arteries, a left main coronary artery (LMCA) and a right coronary artery (RCA), arising from the left (posterior) and right (anterior) aortic or coronary sinuses, respectively, in the proximal ascending aorta. These are the only two branches of the ascending aorta."
"The left coronary artery has a short common stem (and is hence often referred to as the left main coronary artery), that bifurcates into the left circumflex artery (LCx), which courses over the left atrioventricular groove, and the left anterior descending artery (LAD), which passes towards the apex in the anterior interventricular groove. Occasionally, there is a trifurcation (in ~15%), with the third branch, the ramus intermedius, arising between the LAD and LCx. In left dominant hearts, the LCx supplies the posterior descending artery (PDA)."
"acute marginal branches (A1 or AM1, A2 or AM2, etc.)"