2. The heart is surrounded by a membrane called the. Describe the layers of the pericardium.

Transcription

1 Chapter 20 Reading Guide The Cardiovascular System: The Heart Name Section 20.1 Anatomy of the Heart 1. What is the name of the region where the heart is located? 2. The heart is surrounded by a membrane called the. Describe the layers of the pericardium. 3. What is the purpose of the pericardial fluid? 4. Describe the three layers of the heart wall. 5. The heart has chambers. The two superior receiving chambers are the and the two inferior pumping chambers are the vessels returning blood to the heart, called. The paired atria receive blood from blood. Ventricles eject blood from the heart into blood vessels called. 6. What is the purpose of the auricles? 7. The right atrium receives blood from. Blood flow from the right atrium to the through the. 8. What are chordae tendineae? 1

2 9. Describe the path of blood leaving the right ventricle. 10. The left atrium receives blood from the lungs through four. Blood flows from the left atrium to the left ventricle through the or valve. 11. Blood leaves the left ventricle through the and flows into the. Some of the blood in the aorta flows into the which supply blood to the heart wall. 12. Label the following structures on the diagram and then add arrows to indicate the flow of blood through the heart. Right Atrium Right Ventricle Pulmonary Valve Left Atrium Left Ventricle Chordae Tendineae Tricuspid Valve Bicuspid (Mitral) Valve Intraventricular Septum Ascending Aorta Superior Vena Cava Inferior Vena Cava Descending Aorta Pulmonary Trunk Left Pulmonary Artery Right Pulmonary Artery 2

3 13. Explain why there are size differences in the four chambers of the heart. Section 20.2 Heart Valves & Circulation of Blood 14. The tricuspid and bicuspid valves can also be referred to as valves. 15. Describe the arrangement of the chordae tendineae and the papillary muscles when the tricuspid and bicuspid valves are open and closed. 16. The aortic and pulmonary valves are also known as. 17. What causes semilunar valves to open? What causes them to close. 18. There are no valves in the junction between the vessels leading into the two atria. How is backward bloodflow minimized in these vessels? 19. What are the two closed circuits the heart pumps into with each beat? Which side of the heart pumps for each of the circuits? 3

4 20. Below is a diagram of the circuits of the body. Use it to add notes as we discuss in class. 21. In addition to the 2 circuits, the heart itself needs blood flow to supply its tissues. Explain the blood flow to the heart tissue. STOP & WATCH: CC: The Heart Part 1 4

5 Section 20.3 Cardiac Muscle Tissue and the Cardiac Conduction System 22. How do cardiac muscle fibers differ from skeletal muscle fibers? 23. What are autorhythmic fibers and what are their two important functions? 24. Summarize the sequence of the action potential propagation through the conduction system of the heart. 5

6 25. Summarize the steps of an action potential in working atrial and ventricular muscle fibers called contractile fibers. 26. How does epinephrine increase the contraction force of the cardiac fibers? 27. Why can t tetanus occur in cardiac muscle and why is this advantageous? 6

7 28. The heart relies almost exclusively on for the production of ATP. 29. What is an electrocardiogram? 30. What conditions can an EKG determine? 31. The term refers to the phase of contraction, the phase of relaxation is. STOP & WATCH CC: The Heart Part 2 Section 20.4 The Cardiac Cycle 32. How many heart sounds are there and how many can you hear during auscultation? 33. What causes the lubb sound that can be heard? 34. What causes the dupp (dub) sound? Section 20.5 Cardiac Output 35. Define cardiac output. 36. How is cardiac output calculated? 7

8 37. What is a typical resting cardiac output for an adult male? 38. What is cardiac reserve and why is having little cardiac reserve make it hard to function? 39. What and where is the cardiovascular center? 40. What 3 types of receptors provide information to the cardiovascular center? 41. Sympathetic neurons extend from the medulla oblongata into the spinal cord. From the thoracic region of the spinal cord, sympathetic cardiac accelerator nerves extend out to the SA node, AV node, and most portions of the myocardium. When impulses reach the cardiac accelerator nerves, what hormone is released and what effects does this hormone have? 42. What hormone is released by stimulation of the AV & SA nodes by the vagus nerves of the parasympathetic system? What is the effect of this hormone on heart rate? 43. What is tachycardia and why is it a symptom of hyperthyroidism? 8

9 44. Fill in the chart to summarize the effects of ion concentration changes on heart rate. Change in concentration Increased K + Effect on HR Reason Increased Na + Increased Ca Briefly list the effect of age, gender, physical fitness and body temperature on resting heart rate. 46. Describe the benefits of aerobic exercise on the health of the cardiovascular system. 9