Heart location: mediastinum between 2nd rib and 5th intercostal space. Mediastinum: is a division of the thoracic cavity; it contains the heart, thymus gland, portions of the esophagus and trachea, and other structures. Heart function: the human heart is an organ that pumps blood throughout the body via the circulatory system, supplying oxygen and nutrients to the tissues and removing carbon dioxide and other wastes. Pulmonary circulation: moves blood between the heart and the lungs. It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide. The oxygenated blood then flows back to the heart. Systemic circulation: moves blood between the heart and the rest of the body. Location and structure of epicardium, myocardium, endocardium, pericardium, fibrous pericardium. Pericardium: double wall sac/ or just call it epicardium which protects, anchors to surrounding structures, consists of two layered serous pericardium: parietal layer & visceral layer.