Porth's Essentials of Pathophysiology, 4e

445

Disorders of Cardiac Function

C h a p t e r 1 9

Arch of aorta

Pulmonary trunk

Ascending aorta

Left main coronary artery (LCA) Circumflex branch of LCA Left anterior descending artery Anterior interventricular branch of LCA Left marginal artery Lateral (diagonal) branch of anterior IV branch

Sinu-atrial (SA) nodal branch

Site of SA node

Right coronary artery (RCA) within coronary sulcus

Atrioventricular (AV) nodal branch of RCA

Right marginal branch of RCA

Apex of heart

Posterior interventricular branch within posterior interventricular groove

A Anterior view

Arch of aorta

Left pulmonary artery

Superior vena cava (SVC)

Sinu-atrial (SA) nodal branch of RCA

Left coronary artery (LCA)

Circumflex branch of LCA within coronary sulcus

Right pulmonary

veins Right coronary artery (RCA) Atrioventricular nodal branch of RCA

Site of AV node

Crux of heart

FIGURE 19-1. Coronary circulation. (A) Anterior view of the coronary arteries. (B) Posterior view of the coronary arteries and coronary sinus veins. (From Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy. 6th ed. Philadelphia, PA: Wolters Kluwer Health | Lippincott Williams &Wilkins; 2010:146.)

Right marginal branch of RCA Posterior interventricular branch of RCA

Anterior interventricular branch of LCA

B Posteroinferior view

and the anterior papillary muscle of the left ventricle. The circumflex branch of the left coronary artery passes to the left and moves posteriorly in the groove that sepa- rates the left atrium and ventricle, giving off branches that supply the left lateral wall of the left ventricle. The right coronary artery lies in the right atrioventricular groove, and its branches supply the right ventricle. The right coronary artery usually crosses to the back of the

heart, where this vessel forms the posterior descending artery, which, in most individuals, supplies the posterior portion of the heart, interventricular septum, sinoatrial (SA) and atrioventricular (AV) nodes, and posterior pap- illary muscle. 4–6 The right and left coronary arteries or epicardial arteries branch into smaller intramyocardial arteries, which penetrate the myocardium before merging with a