The fully-developed human heart is a four-chambered muscular pump. Its chambers are lined with a single row of flat (endothelial) cells, the endocardium, in contact with blood. Next to it is cardiac muscle, or myocardium, the thickest part of the heart wall. The external layer is the epicardium; or, equally correct, the visceral pericardium which, beyond the heart wall, is continuous with parietal pericardium in the same way that visceral pleura covering the lungs is continuous with parietal pleura at the root of the lung (see Fig. 9.1, p. 5.9). The pericardial cavity between visceral and parietal layers of serous pericardium is a closed sac containing a small amount of lowviscocity fluid. The parietal pericardium is fused externally with the fibrous pericardium, a protective rather than a serous membrane.
KeywordsSuperior Vena Cava Sinus Venosus Pericardial Cavity Cardinal Vein Arch Artery
Unable to display preview. Download preview PDF.