AP151 CARDIOVASCULAR STUDY GUIDE PART 1: HEART
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TEXTBOOK
CHAPTER 13
 Pg 402, 414-427
CHAPTER 14
 Pg 445-449
VISUAL ANALOGY GUIDE
 Pg 56-65
MAIN OBJECTIVES OUTCOMES/STUDENTS WILL BE ABLE TO:
 Review the functional anatomy of the heart and cardiovascular system.
 Describe the conduction system of the heart and the automaticity of the
nodal/pacemaker cells.
 Describe how cardiac muscle cells are stimulated and undergo contraction
(including threshold, depolarization, repolarization, excitation contraction
coupleing and contraction).
 Describe the cardiac cycle and the mechanics of heart function and blood flow
 Define cardiac output and the factors that influence cardiac output.
STUDY QUESTIONS
Overview of CVS and review of functional heart anatomy—review on own as
necessary
1. What is the function of the cardiovascular system?
2. What role dues the heart play in cardiovascular function?
3. What is the pulmonary circuit?
4. What is the systemic circuit?
5. What is the basic function of the pulmonary circuit? Systemic circuit?
6. What chamber(s) of the heart receive blood from veins? What chamber receives
blood from the systemic circuit? Pulmonary Circuit?
7. What chamber of the heart pumps/ejects blood into arteries? What chamber
pumps blood into the systemic circuit? Pulmonary Circuit? (review on own if
necessary)
8. What is the function of the AV valves? (review on own if necessary)
9. Where in the heart is the tricuspid valve? The mitral (bicuspid) valve? (review
on own if necessary)
10. What is the function of the Semilunar Valves? Where is the pulmonary valve
located? Where is the aortic valve located? (review on own if necessary)
11. What side of the heart receives blood from the pulmonary circuit, but pumps
blood into the systemic circuit? (review on own if necessary)
12. What side of the heart receives blood from the systemic circuit, but pumps blood
into the pulmonary circuit? (review on own if necessary)
13. List the vessels, chambers, and valves that a drop of blood would pass through
as it moves through the heart beginning with the vena cavae. (review on own if
necessary)
14. What are the two types of cells discussed in lecture that are found in the heart?
Describe the conduction system of the heart and the automaticity of the
nodal/pacemaker cells.
15. Does the heart need to be stimulated by the nervous system to contract/beat?
16. Is the conduction system made of autorhthmic cells or myocardial cells?
17. What part of the conduction system is the hearts “natural/intrinsic pacemaker”
that initiates the stimulus for contraction in a normal functioning heart?
18. What is the name of the ion channels on nodal/autorhythmic cells that opens in
response to hyperpolarization?
19. What ions do HCN channels allow to diffuse across the membrane? What
direction do they diffuse?
20. What cause HCN channels to open?
21. When a nodal cell has reached threshold, what channels open? What ion flows
through those channels, and in what direction?
22. What ion channels open to repolarize the nodal cell? What ion flows through
them and in what direction?
23. Explain how HCN channels, hyperpolarization, and ion diffusion brings a nodal
cell to threshold and result in spontaneous AP and prevents a stable resting
membrane potential.
24. Be able to interpret and describe a graph of nodal cell electrical activity.
25. How many times per minute does the SA node depolarize without the nervous
system signaling the heart?
26. After the cells of the SA node depolarize what kind of heart cells is the electrical
signal passed to?
27. How does the AP created in the SA node reach the AV node?
28. How does the AP created by the SA node spread through the atria?
29. Generally speaking, what do myocardial cells do in response to AP?
30. What happens to the AP (electrical stimulus) when it reaches/passes through AV
node?
31. Describe the flow of the electrical stimulus/AP from the SA node through the
heart to the stimulation of the contractile cells of the ventricles
32. Why is it important that the conduction of the AP through conductive cells slow
down as it passes through the AV node?
33. Once a depolarization is initiated by the pacemaker cells of the SA node how
does it flow/pass to the contractile cells and from one contractile cell to the next?
Describe how cardiac muscle cells are stimulated and undergo contraction
(including threshold, depolarization, repolarization, excitation contraction
coupleing and contraction).
34. What cells of the heart contract to produce the “beat” of the heart?
35. Describe the shape of these cells.
36. What is the name of the junctions that connect one contractile cell to another?
37. What is the significance of the contractile cells being connected by gap
junctions?
38. How do gap junctions and cell shape work together to spread the AP through the
myocardium?
39. When a myocardial (contractile) cell reaches threshold what channels open and
what ion moves and in what direction?
40. Once a myocardial (contractile) cell depolarizes, what channels open next, what
ion diffuses through those channels, and in what direction does it diffuse?
41. Why do cardiac contractile cells stay in a prolonged period of depolarization and
refractory?
42. What is the usefulness/benefit of this prolonged refractory in myocardial cells?
43. What is the plateau and what causes repolarization of the cell after the plateau is
complete?
44. Do myocardial (contractile) cells have t-tubules? Sarcoplasmic reticulum?
45. Cardiac contractile cells propagate AP’s with VG Na+ channels, what happens
when the AP reaches a T-tubule?
46. Are the VG Ca+ channels in the T-tubules of myocardial cells physically
connected (i.e., mechanically linked) to the calcium release channels in the SR?
47. How is the SR signaled to release calcium in heart muscle? How is this different
than is skeletal muscle?
48. In cardiac muscle cells (contractile cells) actin and myosin interact in exactly the
same way as in skeletal muscle, but the calcium that binds troponin comes from
two different sources. What are those two different sources for calcium and
which source provides the majority of calcium.
49. Once stimulated with an action potential, do cardiac contractile cells contract
slowly or quickly?
50. What is an ECG/EKG?
51. What cardiac event does the P wave represent? QRS wave? T wave?
52. What cardiac events does the PR interval correspond to? The QT interval?
Describe the cardiac cycle and the mechanics of heart function
53. What is systole? Diastole?
54. What is the relationship between the volume of the heart’s chamber and the
pressure within them?
55. When the chambers of the heart contract what happens to their volume?
56. If there is an area of high pressure and another area of low pressure, which
direction will blood flow.
57. When does blood flow into the ventricles?
58. When is blood pumped out of the ventricles?
59. In relationship to systole and diastole as well as ventricular pressure, when do
the AV valves close? Open?
60. In relationship to systole and diastole as well as ventricular pressure, when do
the semilunar valves close? Open?
61. What happens when the pressure in the ventricles is greater then that of the
atria?
62. What happens when the pressure in the ventricles is greater then that in the
arteries?
63. What happens when the pressure in the ventricles is less then that of the atria?
Ventricles?
64. what is the function of the hearts valves?
65. What accounts for 70-80% of ventricular filling?
66. What is the function of atrial contraction?
67. What is the first heart sound? Second heart sound?
68. Why is it important that the conduction of the AP through conductive cells slow
down as it passes through the AV node?
69. What happens if the left and right side of the heart are not pumping out or
receiving equal volumes of blood?
70. If systemic blood pressure increases what does this require the heart to do in
order to eject blood into that circuit?