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Anatomy & Physiology
Ch. 18 The Cardiovascular System: The Heart
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Re-read the section! Pg. 677-709
 Look at all of the pictures and figures and read the captions!!
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Look at the Objectives for the section (p. 677) and the Chapter Summary for the section (p. 709-711).
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Try to answer the following questions without looking at the book first and then go back and answer the
questions you didn’t know or weren’t sure about (that lets you know your strengths and weaknesses).
Heart Anatomy
Size, Location, Orientation
1. What is the name of the cavity within the thorax that the heart is enclosed in?
2. Describe the position of the heart in relation to the diaphragm, the vertebral column, the sternum, and
the lungs.
3. Identify where the base and apex is on the heart.
Coverings of the Heart
4. What is the pericardium?
5. What is different between the fibrous pericardium and the serous pericardium? (make sure to mention
the differences between the structure AND the function)
6. What is the purpose of the serous fluid within the pericardial cavity?
7. Describe what pericarditis is.
Layers of the Heart Wall
8. What are the three layers of the heart wall?
9. Describe the structure and function of the fibrous skeleton of the heart.
Chambers and Associated Great Vessels
10. Name the four chambers of the heart and the partitions that divide them.
11. Name the three sulci (sin. sulcus) on the heart and where they are located.
12. Where are the auricles located and what do they do?
13. Where are pectinate muscles located within the heart?
14. What is the fossa ovalis? Where is it located?
15. Why are atria described as “receiving chambers”?
16. How does blood enter the right atrium? How does blood enter the left atrium?
17. Where is trabeculae carne located within the heart?
18. What is the job of papillary muscles?
19. Ventricles are called “discharging chambers” – where does the right ventricle discharge to? Where does
the left ventricle discharge to?
Pathway of Blood through the Heart
20. What is the difference between the pulmonary circuit and the systemic circuit?
21. Which side of the heart serves the pulmonary circuit and which one serves the systemic circuit?
22. True or False: Veins always carry oxygen poor blood.
23. Which ventricle has thicker myocardium? Why is this important for its function?
Coronary Circulation
24. What part of the body does coronary circulation serve?
25. Where do the right and left coronary arteries arise from?
26. Where does the coronary sinus empty into?
27. What is a myocardial infarction? What causes it?
Heart Valves
28. Where are the atrioventricular (AV) valves located? What is the name for the right AV valve? What is
the name for the left AV valve?
29. What is the job of chordae tendinae?
30. Where are the semilunar valves located? What is the name of the semilunar valve that leads to the
systemic circuit? What is the name of the semilunar valve that leads to the pulmonary circuit?
Properties of Cardiac Muscle Fibers
Microscopic Anatomy
31. Compare and contrast skeletal and cardiac muscle cells.
32. What two membrane junctions are found within the intercalated discs of cardiac muscle cells? What are
their jobs?
33. Why are there more mitochondria in cardiac muscle cells?
34. True or False: There are no triads in cardiac muscle cells.
Mechanism and Events of Contraction
35. Name and describe three fundamental differences between skeletal muscle and cardiac muscle.
36. Place the following events in the correct order:
a. Opening of Ca2+ channels and release of Ca2+ ions
b. Closing of Na2+ channels
c. Opening of K+ channels and release of K+ ions
d. Opening of Na2+ channels and release of Ca2+ ions
e. Closing of Ca2+ channels
37. In what directions (into or out of the cell) do the ions travel from the previous question?
Energy Requirements
38. Which type of respiration (aerobic or anaerobic) does cardiac muscle rely on?
Heart Physiology
Electrical Events
39. What is the function of the intrinsic cardiac conduction system?
40. List the sequence of areas where impulses will travel along the heart (there are 5).
41. Why is the sinoatrial node called the heart’s “pacemaker”?
42. Why is the impulse delayed at the AV node?
43. What is the other name for atrioventricular bundle?
44. What is the total time between the initiation of an impulse by the SA node and depolarization of the
last ventricular muscle cells?
45. What is fibrillation? What does defibrillation do?
46. Where are the cardiac centers located?
47. What is an electrocardiogram (ECG or EKG)?
48. Look at Figure 18.6 on page 696. Distinguish between the P wave, QRS complex, and the T wave.
Heart Sounds
49. What causes the two sounds that are often described as “lub-dup”?
Mechanical Events: The Cardiac Cycle
50. What is the difference between systole and diastole?
Cardiac Output
51. Define cardiac output.
52. What is stroke volume? What are the three most important factors that affect stroke volume?
53. If stroke volume declines, cardiac output is maintained by increasing heart rate and contractility. What
factors can increase or decrease heart rate?
54. Define congestive heart failure.