The document describes the anatomy of the heart. It discusses the location of the heart in the chest, its coverings including the pericardium, and its four chambers - the right and left atria which receive blood, and the right and left ventricles which pump blood out. It also describes the pathway of blood flow through the heart and lungs, the coronary circulation which supplies blood to the heart muscle, and the heart valves that ensure one-way blood flow.

2. Heart Anatomy Figure 18.1

5. Pericardial Layers of the Heart Figure 18.2

9. External Heart: Anterior View Figure 18.4b

12. External Heart: Posterior View Figure 18.4d

13. Gross Anatomy of Heart: Frontal Section Figure 18.4e

17. Pathway of Blood Through the Heart and Lungs Figure 18.5

19. Coronary Circulation: Arterial Supply Figure 18.7a

20. Coronary Circulation: Venous Supply Figure 18.7b

23. Heart Valves Figure 18.8a, b

24. Heart Valves Figure 18.8c, d

26. Microscopic Anatomy of Heart Muscle Figure 18.11

27. Conduction System of the Heart Figure 18.14a