Key Questions for Understanding the Anatomy of the Heart 1. Major Function of the Cardiovascular System: Transportation of oxygen, nutrients, cell wastes, hormones, and other substances vital for homeostasis 2. Define and describe the 2 parts of the pericardium The pericardium is a double sac of serous membrane enclosing the heart The epicardium tightly hugs the external surface of the heart The parietal pericardium anchors the heart to surrounding structures such as the sternum and diaphragm 3. Function of serous fluid produced by the pericardium This serous fluid allows the heart to beat easily in a friction-less environment 4. What is the structure and function of the myocardium? The myocardium is made of thick bundles of cardiac muscle twisted into ring-like arrangements It is the layer of the heart that actually contracts 5. What is the endocardium and what is its function? The endocardium is a thin, glistening sheet of endothelium that lines the heart chambers. It is continuous with the linings of the blood vessels entering and leaving the heart It helps blood flow smoothly through the heart 6. What is the primary function of the atria? The atria are receiving chambers for blood returning to the heart from either the body or the lungs. 7. What is the primary function of the ventricles? The ventricles are discharging chambers which pump blood out of the heart to either the lungs or the body. 8. The steps of pulmonary circulation: 1. Oxygen-poor blood returns to the heart from the superior and inferior vena cavae 2. This blood enters the right atrium 3. Blood is pumped out of the right ventricle into the pulmonary arteries 4. Pulmonary arteries carry blood to the lungs, in which oxygen is picked up and carbon dioxide is unloaded 5. Oxygen-rich blood returns to the left-side of the heart through the 4 pulmonary veins 6. This blood enters the left atrium 9. The process of systemic circulation: 1. Oxygenated blood enters the left atrium 2. This blood is pumped out of the left ventricle into the aorta 3. Oxygenated blood is delivered to the body cells by the arteries 4. Veins carry blood back to the vena cavae 5. The vena cavae enter the right atrium 10. Contrast the function of pulmonary circulation with systemic circulation The function of pulmonary circulation is to supply the blood with oxygen. The function of systemic circulation is to deliver oxygen and nutrients to the cells of the body. 11. What is the function of the valves of the heart? The valves of the heart allow blood to flow in only one direction through the heart chambers. 12. What is the location and function of the AV valves? The AV valves are located between the atria and the ventricles on each side of the heart. They prevent backflow into the atria when the ventricles contract. 13. Location and Function of the Semilunar Valves: The semilunar valves are located at the bases of the 2 arteries leaving the ventricles. Their function is to prevent arterial blood from re-entering the heart 14. What is the source of the blood that nourishes the heart muscle? The source of blood for the muscles of the heart is the right and left coronary arteries 15. From what do the coronary arteries branch? The coronary arteries branch from the base of the aorta 16. Into what do the cardiac veins empty? The cardiac veins empty into the coronary sinus, which empties into the right atrium 17. What is angina pectoris, and what can it lead to? Angina pectoris is chest pain caused by the myocardium being deprived of oxygen It can lead to a myocardial infarction, or heart attack