Upon completion of this lesson, the successful participant will be able to: Describe the size, shape, location, and orientation of the heart in the thorax; name the coverings of the heart; describe the structure and function of each of the three layers of the heart wall; describe the structure and functions of the four heart chambers; name each chamber and provide the name and general route of its associated great vessel(s);. | CHAPTER 18 The Cardiovascular System: The Heart: Part A HEART ANATOMY Approximately the size of a fist Location In the mediastinum between second rib and fifth intercostal space On the superior surface of diaphragm Two-thirds to the left of the midsternal line Anterior to the vertebral column, posterior to the sternum Enclosed in pericardium, a double-walled sac PLAY Animation: Rotatable heart Figure Point of maximal intensity (PMI) Diaphragm (a) Sternum 2nd rib Midsternal line Figure (c) Superior vena cava Left lung Aorta Parietal pleura (cut) Pericardium (cut) Pulmonary trunk Diaphragm Apex of heart PERICARDIUM Superficial fibrous pericardium Protects, anchors, and prevents overfilling PERICARDIUM Deep two-layered serous pericardium Parietal layer lines the internal surface of the fibrous pericardium Visceral layer (epicardium) on external surface of the heart Separated by fluid-filled pericardial cavity (decreases friction) Figure Fibrous pericardium Parietal layer of serous pericardium Pericardial cavity Epicardium (visceral layer of serous pericardium) Myocardium Endocardium Pulmonary trunk Heart chamber Heart wall Pericardium Myocardium LAYERS OF THE HEART WALL Epicardium—visceral layer of the serous pericardium LAYERS OF THE HEART WALL Myocardium Spiral bundles of cardiac muscle cells Fibrous skeleton of the heart: crisscrossing, interlacing layer of connective tissue Anchors cardiac muscle fibers Supports great vessels and valves Limits spread of action potentials to specific paths LAYERS OF THE HEART WALL Endocardium is continuous with endothelial lining of blood vessels Figure Fibrous pericardium Parietal layer of serous pericardium Pericardial cavity Epicardium (visceral layer of serous pericardium) Myocardium Endocardium Pulmonary trunk Heart chamber Heart wall Pericardium Myocardium CHAMBERS Four chambers Two atria Separated internally by the interatrial septum Coronary sulcus (atrioventricular groove) encircles the junction of . | CHAPTER 18 The Cardiovascular System: The Heart: Part A HEART ANATOMY Approximately the size of a fist Location In the mediastinum between second rib and fifth intercostal space On the superior surface of diaphragm Two-thirds to the left of the midsternal line Anterior to the vertebral column, posterior to the sternum Enclosed in pericardium, a double-walled sac PLAY Animation: Rotatable heart Figure Point of maximal intensity (PMI) Diaphragm (a) Sternum 2nd rib Midsternal line Figure (c) Superior vena cava Left lung Aorta Parietal pleura (cut) Pericardium (cut) Pulmonary trunk Diaphragm Apex of heart PERICARDIUM Superficial fibrous pericardium Protects, anchors, and prevents overfilling PERICARDIUM Deep two-layered serous pericardium Parietal layer lines the internal surface of the fibrous pericardium Visceral layer (epicardium) on external surface of the heart Separated by fluid-filled pericardial cavity (decreases friction) Figure Fibrous pericardium Parietal layer
