1. The heart functions as: Answer The pump forthe circulating blood in both the pulmonaryand systemic circulations. 2. The heart is located: Answer In the mediastinum between the lungs and is enclosed inthe double-walled pericardial sac 3. The outer fibrous pericardium: Answer Anchors the heart to the diaphragm. 4. The visceral pericardium, also called the epicardium: Answer Consists of a serousmembrane that provides a small amount of lubricating fluid within the pericardialcavity between the two pericardial membranes to facilitate heart movements. 5. The middle layer ofthe heart isthe myocardium: Answer Composed ofspecialized cardiac muscle cells that contract rhythmically and forcefully to pump blood throughoutthe organs. 6. The left ventricular wall is thicker: Answer Because it must eject blood into the extensive systemic circulation. 7. The inner layer of the heart is the endocardium: Answer Forms the four heart valvesthat separate the chambers of the heart and ensure one-way flow of blood.