LEFT CORONARY ARTERY
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Left Coronary Artery - Overview, Preview from the app.
WHY THIS MATTERS
The left coronary artery supplies oxygenated blood to the left side of your heart. Understanding how it branches into the anterior interventricular artery (LAD) and the circumflex artery helps you see how your heart muscle receives the blood supply it needs to keep pumping.
LEFT CORONARY ARTERY
The left coronary artery (LCA) originates from the left side of your aorta (left aortic sinus). It supplies oxygenated blood to the left part of your heart. The LCA most commonly bifurcates into two arteries: the circumflex artery and the anterior interventricular artery.
ANTERIOR INTERVENTRICULAR ARTERY
The anterior interventricular artery, also known as the left anterior descending artery (LAD), originates from the left main coronary artery. It descends along the interventricular sulcus and gives rise to multiple important branches: the conal branch, anterior ventricular branches, diagonal branch, and septal branches.
BRANCHES OF ANTERIOR INTERVENTRICULAR ARTERY
The anterior interventricular artery gives off four key branches. The conal branch supplies your conus arteriosus and part of the right ventricle. The anterior ventricular branches perfuse the anterior wall of your heart. The diagonal branch courses diagonally to supply the anterolateral wall of your left ventricle. The septal branches penetrate and supply a significant portion of your interventricular septum.
Conal Branch
The conal branch is a small branch that supplies your conus arteriosus. It also supplies part of your right ventricle.
Anterior Ventricular Branches
The anterior ventricular branches supply the anterior cardiac wall. They perfuse the anterior wall of your heart.
Diagonal Branch
The diagonal branch courses diagonally from the main artery. It supplies the anterolateral wall of your left ventricle.
Septal Branches
The septal branches penetrate the interventricular septum. They supply a significant portion of your interventricular septum.
CIRCUMFLEX ARTERY OF HEART
Circumflex Artery of Heart, Preview from the app.
The circumflex artery curves around your heart. It supplies blood to your left atrium, the lateral wall of your left ventricle, and the posterior wall of your left ventricle. Its branches include the atrial branches, atrial anastomotic branch, left marginal branch, and inferior left ventricular branch.
BRANCHES OF CIRCUMFLEX ARTERY
The circumflex artery gives off four branches. The atrial branches supply your left atrial wall. The atrial anastomotic branch provides collateral circulation by connecting with other atrial arteries. The left marginal branch courses along the left cardiac margin to supply the lateral wall of your left ventricle. The inferior left ventricular branch descends inferiorly to supply the inferior wall of your left ventricle.
Atrial Branches
The atrial branches supply your left atrium. They perfuse the left atrial wall.
Atrial Anastomotic Branch
The atrial anastomotic branch is a connecting vessel. It links the circumflex artery with other atrial arteries and provides collateral circulation to your left atrium.
Left Marginal Branch
The left marginal branch courses along the left cardiac margin. It supplies the lateral wall of your left ventricle.
Inferior Left Ventricular Branch
The inferior left ventricular branch descends inferiorly. It supplies the inferior wall of your left ventricle.
CHECK YOUR UNDERSTANDING
1. The left coronary artery most commonly bifurcates into which two arteries?
Reveal Answer
The circumflex artery and the anterior interventricular artery (LAD).
2. Name the four branches of the anterior interventricular artery.
Reveal Answer
The conal branch, anterior ventricular branches, diagonal branch, and septal branches.
3. What structures does the circumflex artery supply?
Reveal Answer
The left atrium, lateral wall of the left ventricle, and posterior wall of the left ventricle.
WHAT'S NEXT
Now that you understand how the left coronary artery branches to supply your heart, the next page covers the Cardiac Veins. You will explore how deoxygenated blood drains from your heart muscle back to the right atrium via the coronary sinus, great cardiac vein, middle cardiac vein, small cardiac vein, and anterior cardiac veins.
Review this page again in 3 days to reinforce what you have learned.
BIBLIOGRAPHY
1. Gray H, Lewis W. Angiology. In: Anatomy of the Human Body. 1918. p. 526–542.
2. Gosling JA, Harris PF, Humpherson JR, Whitmore I, Willan PLT. Human anatomy: color atlas and textbook. 6th ed. 2017. 45–58 p.
3. Anderson RH, Spicer DE, Hlavacek AM, Cook AC, Backer CL. (2013). Anatomy of the cardiac chambers. In Wilcox’s Surgical Anatomy of the Heart (4th ed., pp. 13–50). Cambridge University Press.
4. Fritsch H, Kuehnel W. Color Atlas of Human Anatomy. Vol. Volume 2, Color Atlas and Textbook of Human Anatomy. 2005. 10–42 p.
5. Moore K, Dalley A, Agur A. Clinically Oriented Anatomy. Vol. 7ed, Clinically Oriented Anatomy. 2014. 132–151 p.
6. Ho SYen. Anatomy for Cardiac Electrophysiologists: A Practical Handbook. Cardiotext Pub; 2012. 5–27 p.
7. Standring S, editor. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 41st ed. London: Elsevier; 2016.
8. Moore KL, Agur AMR, Dalley AF. Essential Clinical Anatomy. 5th ed. Philadelphia: Wolters Kluwer; 2015.
