Download Chapter 20 Reading Guide - Student

Name ____________________________
Chapter 20 Reading Guide
The Cardiovascular System: The Heart
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
pericardium.
. Describe the layers of the
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
inferior pumping chambers are the
. The paired atria receive blood from blood
vessels returning blood to the heart, called
blood vessels called
and the two
. Ventricles eject blood from the heart into
.
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
9. Describe the path of blood leaving the right ventricle.
10. The left atrium receives blood from the lungs through four
from the left atrium to the left ventricle through the
11. Blood leaves the left ventricle through the
Some of the blood in the aorta flows into the
. Blood flows
or
and flows into the
valve.
.
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
Left Atrium
Left Ventricle
Tricuspid Valve
Bicuspid (Mitral) Valve
Ascending Aorta
Superior Vena Cava
Descending Aorta
Pulmonary Trunk
Right Pulmonary Artery
Pulmonary Valve
Chordae Tendineae
Intraventricular Septum
Inferior Vena Cava
Left Pulmonary Artery
2
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
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 https://www.youtube.com/watch?v=X9ZZ6tcxArI
4
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
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
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 https://www.youtube.com/watch?v=FLBMwcvOaEo
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
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
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 2+
45. 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