The major branches of the left coronary artery are:

The left coronary artery is a crucial vessel that supplies blood to the heart. Its major branches are essential for understanding cardiac perfusion. The circumflex branch and the anterior descending branch are indeed the primary branches of the left coronary artery.

The anterior descending branch courses down the front of the heart and supplies the majority of the anterior wall of the left ventricle and the interventricular septum. Meanwhile, the circumflex branch runs laterally and supplies the lateral and posterior walls of the left ventricle, as well as parts of the left atrium.

Understanding these anatomical segments is vital for anyone involved in cardiovascular perfusion and intervention, as proper knowledge ensures effective surgical planning and prevention of complications. The other proposed combinations of branches do not accurately represent the primary branches of the left coronary artery, underscoring the importance of knowing these critical vascular structures.