Pericardium Anatomy PDF

 The pericardium is a fibroserous membrane that covers the heart and the beginning of its great vessels  The pericardium is a closed sac composed of two layers  The tough external layer, the fibrous pericardium, is continuous with the central tendon of the diaphragm  The internal s...

 The pericardium is a fibroserous membrane that covers the heart and the beginning of its great vessels  The pericardium is a closed sac composed of two layers  The tough external layer, the fibrous pericardium, is continuous with the central tendon of the diaphragm  The internal surface of the fibrous pericardium is lined with a glistening serous membrane, the parietal layer of serous pericardium  The serous pericardium is composed mainly of mesothelium, a single layer of flattened cells forming an epithelium that lines both the internal surface of the fibrous pericardium and the external surface of the heart  The fibrous pericardium is continuous superiorly with the tunica adventitia of the great vessels entering and leaving the heart and with the pretracheal layer of deep cervical fascia  Attached anteriorly to the posterior surface of the sternum by the sternopericardial ligaments  Bound posteriorly by loose connective tissue to structures in the posterior mediastinum  Continuous inferiorly with the central tendon of the diaphragm, the site of continuity has been referred to as the pericardiacophrenic ligament  The heart and roots of the great vessels within the pericardial sac lie posterior to the sternum, costal carti- lages, and anterior ends of the 3rd–5th ribs on the left side The heart and pericardial sac are situated obliquely, approximately two thirds to the left and one third to the right of the median plane  The pericardial cavity is the potential space between opposing layers of the parietal and visceral layers of serous pericardium It normally contains a thin film of fluid that enables the heart to move and beat in a frictionless environment  The visceral layer of serous pericardium forms the epicardium, the outermost of three layers of the heart wall It extends onto the beginning of the great vessels, becoming continuous with the parietal layer of serous pericardium (1) where the aorta and pulmonary trunk leave the heart and (2) where the SVC, inferior vena cava (IVC), and pulmonary veins enter the heart  The arterial supply of the pericardium is mainly from a slender branch of the internal thoracic artery, the pericardiacophrenic artery, that often accompanies or at least parallels the phrenic nerve to the diaphragm Smaller contributions of blood come from the: Musculophrenic artery, a terminal branch of the internal thoracic artery Bronchial, esophageal, and superior phrenic arteries, branches of the thoracic aorta Coronary arteries (visceral layer of serous pericardium only), the first branches of the aorta  The nerve supply of the pericardium is from the: Phrenic nerves (C3–C5), primary source of sensory fibers Vagus nerves, function uncertain Sympathetic trunks, vasomotor