By the end of this chapter the student will be able to:
Describe the pericardium and its sinuses.
Outline the anatomical basis of clinical examination of the heart.
Examine the internal features of the heart chambers.
Explain the functional anatomy of the heart valves.
Highlight the conducting system of the heart.
Outline the course of the coronary arteries and the cardiac veins.
Map the area of supply of the coronary arteries.
Explain the anatomical basis of referral of cardiac ischemic pain.
Summarize the microscopic anatomy of the heart.
Knowing the anatomical structure of the heart is essential for understanding its function, performing clinical examination, and interpreting radiological findings. The heart consists of 4 chambers: 2 atria (ie, the right atrium and the left atrium) and 2 ventricles (ie, the right ventricle and the left ventricle). Furthermore, the heart contains 4 valves: 2 atrioventricular valves between each atrium and ventricle (ie, the tricuspid valve in the right side and the mitral valve in the left), as well as the pulmonary and aortic valves that originate from the right and the left ventricles, respectively. The heart is located behind the sternum; however, it normally lies “down” with the apex pointing toward the left side. This chapter provides a succinct overview of the gross anatomy of the heart and its blood vessels as well as some clinical aspects pertinent to its structure.
The pericardium is a fibroserous sac that encloses the heart and the roots of the great vessels (Fig. 2.1A, B).
A. Coronary section through the thorax. B. Layers of the pericardial sac. C. Anterior (sternocostal) surface of the heart. D. Posterior (base) and inferior (diaphragmatic) surface of the heart. E. Coronary grooves (anterior view). F. Coronary grooves (posterior view). (Reproduced, with permission, from Morton DA, Foreman KB, Albertine KH. The Big Picture: Gross Anatomy. New York, NY: McGraw-Hill; 2011.)
Layers of the Pericardium
The fibrous pericardium is a strong outer layer that fuses with the walls of the great vessels superiorly and with the central tendon of the diaphragm inferiorly. The pericardium is anteriorly attached to the sternum by weak sternopericardial ligaments.
The serous pericardium is enclosed within the fibrous pericardium. Like other serous membranes (eg, pleura, peritoneum), the serous pericardium itself consists of parietal and visceral layers which are continuous with each other.
The parietal layer of the serous pericardium lines and is firmly adhered to the fibrous pericardium. There is no space in between the parietal layer and the fibrous layer. However, the parietal layer is folded to become continuous with the visceral layer around the root ...