Download LEARNING OBJECTIVE 9: Compare the pulmonary and systemic

CHAPTER 15
CARDIOVASCULAR SYSTEM
LEARNING OBJECTIVE 1: Name the organs of the cardiovascular system and discuss their functions.
Lecture Suggestions and Guidelines
1. Give an overview of the cardiovascular system, its associated organs, and the system’s role in maintaining
homeostasis.
2. Begin discussions of the anatomy and physiology of the heart, arteries, and veins.
3. Discuss why the cardiovascular system is vital for survival.
Application Question(s)
1. Ask students to create an illustration, which explains the path of blood through the heart and pulmonary circuit.
Use the flowchart provided in the textbook as a guide, but the illustrations should be original.
Answer: Once the students have created this illustration, they should practice explaining it to someone with a
limited science background. If their audience understands the explanation, it is a good indication that the
student understands the material as well.
Critical Thinking Issue(s)
1. Discuss Tetrology of Fallot. A description of the four defects occurring together will aid the students’
understanding of the chambers of the heart, septa, valves, and the importance of one-way blood flow.
Answer: Responses should include a discussion of pulmonary stenosis, ventricular septal defects, right
ventricular hypertrophy, and an overriding aorta.
LEARNING OBJECTIVE 2: Name and describe the locations of the major parts of the heart and
discuss the function of each part.
Lecture Suggestions and Guidelines
1.
2.
3.
4.
5.
Discuss the size and location of the heart.
Describe the coverings of the heart.
Define the epicardium, myocardium, and endocardium, the three layers, which form the heart wall.
Describe the structure and function of the heart chambers and valves.
Describe the skeleton of the heart.
Application Question(s)
1. Apply the student’s knowledge of the structure and role of the human skeleton to what is termed the “skeleton”
of the heart.
Answer: Discuss in terms of providing structure and framework, protection, and attachment points for muscle
fibers.
Critical Thinking Issue(s)
1. Compare the possible consequences of “left-side” and “right-side” heart failure.
Answer: The discussion should include a description of pulmonary congestion resulting from “left-side” failure
to pump blood, which has returned from the lungs, into the systemic circulation. Leakage continues into the
lungs causing pulmonary edema. “Right-side” failure results in congestion in the distal regions of the systemic
circuit, causing peripheral edema primarily in the extremities.
LEARNING OBJECTIVE 3: Trace the pathway of the blood through the heart and the vessels of the
coronary circulation.
Lecture Suggestions and Guidelines
1. Describe the path of blood through the heart and pulmonary circuit.
2. Discuss the blood supply to the heart, beginning with the right and left coronary arteries.
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3. Compare the flow of blood in arteries to blood flow in the myocardium during ventricular contraction.
4. Describe how the myocardium is drained by the cardiac veins, which eventually join the coronary sinus.
Application Question(s)
1. Ask students to develop a flowchart, which describes the path of blood through the coronary circulation. Begin
the flowchart with the aorta and end with the right atrium.
Answer: The use of index cards for this application is helpful and students may use figures provided in the
textbook as guidelines.
Critical Thinking Issue(s)
1. Discuss reasons why an untreated streptococcal infection may lead to more serious consequences.
Answer: A streptococcal infection may become systemic. As the body continues to build antibodies against the
bacteria, an autoimmune disease may develop. Damage to the heart valves, heart muscles, and the pericardium
is possible, because the antibodies mistakenly recognize “self” as foreign.
LEARNING OBJECTIVE 4: Discuss the cardiac cycle and explain how it is controlled.
and
LEARNING OBJECTIVE 5: Identify the parts of a normal ECG pattern, and discuss the significance of
this pattern.
Lecture Suggestions and Guidelines
1.
2.
3.
4.
Give an overview of the cardiac cycle.
Describe the causes of heart sounds.
Describe the structure and function of cardiac muscle fibers and the cardiac conduction system.
Discuss ways in which the cardiac cycle may be regulated.
Application Question(s)
1. Ask students to explain the major events of the cardiac cycle, including the causes of two heart sounds, lubb
and dupp.
Answer: Responses should include the events, which take place during mid to late diastole, ventricular systole,
and early diastole. “Lubb” occurs during ventricular contraction, when the A-V valves are closing. “Dupp”
occurs during ventricular relaxation, when the semilunar valves are closing.
Critical Thinking Issue(s)
1. Describe the three major waves found on an electrocardiogram. Provide examples of ECGs to the class for
discussion. What conditions might abnormal waves illustrate?
Answer: A discussion of the P wave, QRS complex, and T wave should ensue. Describe abnormalities in the
shape of waves, which may be indicative of a myocardial infarct, ischemia, fibrillation, or other intrinsic
conduction system problem.
LEARNING OBJECTIVE 6: Compare the structures and functions of the major types of blood vessels.
Lecture Suggestions and Guidelines
1. Give an overview of the function of blood vessels.
2. Discuss the structure and function of arteries and arterioles.
3. Describe the structure of capillaries. Include a description of capillary permeability, capillary arrangement, and
regulation of capillary blood flow. Address the roles of diffusion, filtration, and osmosis during capillary
exchange.
4. Discuss the structure and function of veins and venules.
Application Question(s)
1. In what ways are the structure and function of arteries and veins similar? In what ways are they different?
Answer: Students may summarize this comparison in a table to include parameters such as overall function,
direction of blood flow, thickness of wall, lumen size, ability to withstand pressure, ability to expand/stretch,
and the appearance of valves to insure one-way blood flow.
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Critical Thinking Issue(s)
1. Compare/contrast arteriosclerosis and atherosclerosis.
Answer: Arteriosclerosis generally implies a hardening of the arteries, in which smooth muscle cells are
gradually replaced by nonelastic scar tissue. It is the end stage in the process of atherosclerosis, which describes
the occlusion of an artery due to plaque buildup. The artery walls thicken, gradually narrowing the lumen.
LEARNING OBJECTIVE 7: Describe the mechanisms that aid in returning venous blood to the heart.
Lecture Suggestions and Guidelines
1. Emphasize the major functions of veins.
2. Discuss the role of valves in returning blood to the heart.
3. Introduce pressure changes, lumen size, and skeletal muscle activity as other means by which venous blood is
returned to the heart.
Application Question(s)
1. Apply the knowledge gained by this learning objective regarding the structure and function of a vein by
comparing a vein to a lymphatic vessel. How are they similar?
Answer: Responses should include a discussion of pressure within the vessel, the presence of valves to insure
one-way blood flow, direction of flow, thinness of vessel walls, and the pumping action of smooth muscle walls
to facilitate circulation.
Critical Thinking Issue(s)
1. Ask students to prepare a short paper on diseases of the veins, for example, varicose veins. The report should
include etiology, signs/symptoms, causes, and treatments.
Answer: Varicose veins result from increased pressure in a superficial vein due to the pooling of blood. Veins
become swollen, painful, and appear knotty under the skin. Some causes may be standing for extended periods
of time, pregnancy, heredity, or obesity. Varicose veins are treated through rest and elevation, support,
stripping, or removal.
LEARNING OBJECTIVE 8: Explain how blood pressure is produced and controlled.
Lecture Suggestions and Guidelines
1.
2.
3.
4.
Define blood pressure in terms of systolic and diastolic pressures.
List factors that influence arterial blood pressure.
Describe ways in which blood pressure is controlled.
Describe venous blood flow and central venous pressure.
Application Question(s)
1. Discuss various factors, which influence blood pressure. Develop a list and ask students to give specific
examples of each.
Answer: Factors to discuss include increases in blood volume, heart rate, stroke volume, blood viscosity, and
peripheral resistance. Integrate these factors with the role of the autonomic nervous system, kidneys, adrenal
glands, exercise, and diet in sustaining homeostasis.
Critical Thinking Issue(s)
1. Discuss how cardiac output is related to the volume of blood entering the heart.
Answer: The discussion should include the following sequence of events: 1) increased blood volume enters the
heart; 2) increased stretching of myocardial fibers; 3) greater force of myocardial contraction; 4) greater stroke
volume; which leads to 5) increased cardiac output.
LEARNING OBJECTIVE 9: Compare the pulmonary and systemic circuits of the cardiovascular
system.
Lecture Suggestions and Guidelines
1. Define pulmonary circuit.
2. Trace the flow of blood from the right ventricle through the pulmonary circuit.
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3. Describe pulmonary edema.
4. Trace the flow of blood from the left side of the heart to the body cells and back to the right atrium.
Application Question(s)
1. Ask students to develop two sets of index cards. The first set contains eight cards labeled in the following way:
1) blood from systemic circuit; 2) vena cavae; 3) right atrium; 4) tricuspid valve; 5) right ventricle; 6)
pulmonary valve; 7) pulmonary trunk; and 8) pulmonary arteries. The second set contains eight cards labeled in
the following way: 1) lungs; 2) pulmonary veins; 3) left atrium; 4) bicuspid valve; 5) left ventricle; 6) aortic
valve; 7) aorta; and 8) blood to systemic circuit. Shuffle the cards and ask students to place them in the correct
sequence to describe the path of blood through the heart and pulmonary circuit.
Critical Thinking Issue(s)
1. Investigate drugs, which are currently used to treat hypertension. The report should include name, method of
administration, contraindications, chemical composition, and possible side effects.
Answer: Drugs to investigate might include ACE inhibitors, beta blockers, calcium channel blockers, and
diuretics.
LEARNING OBJECTIVE 10: Identify and locate the major arteries and veins of the pulmonary and
systemic circuits.
Lecture Suggestions and Guidelines
1. Describe the arterial system in terms of the principle branches of the aorta.
2. Discuss the arteries, which serve the head and neck.
3. Describe the arteries of the shoulder and upper limb, thoracic and abdominal walls, and the pelvis and lower
limb.
4. Give an overview of the characteristics of the venous pathways.
5. Describe the veins of the head, neck, brain, shoulder, and upper limb.
6. Discuss the veins which serve the abdominal and thoracic walls, abdominal viscera, and the lower limb and
pelvis.
Application Question(s)
1. Repetition is the key to learning the names and body areas served for the major arteries and veins. Categorizing
the arteries as branches of a portion of the aorta is helpful. Veins are often named similarly to an adjacent
artery. Students may refer to nomenclature for bones, muscles, nerves, and body landmarks learned in previous
textbook chapters for assistance.
Critical Thinking Issue(s)
1. Discuss the interconnections of the cardiovascular system with each of the other major body systems introduced
in Chapter One. Ask students to give specific examples of these interactions and explain their effect on
homeostatic balance.
Answer: Responses will vary.
LEARNING OBJECTIVE 11: Describe life-span changes in the cardiovascular system.
Lecture Suggestions and Guidelines
1. Describe the general changes in the cardiovascular system.
2. Discuss the effects of aging on the heart and heart valves.
3. Identify the changes that are most evident in the arteries.
Application Question(s)
1. Ask students to develop a health/wellness program that would aid in deterring the effects of age on the
cardiovascular system.
Answer: Responses will vary, but should include an emphasis on proper diet and exercise. The specifics of such
programs will depend on the individual participant.
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Critical Thinking Issue(s)
1. Compare and contrast the changes that occur with age in the arteries with those that occur in the veins.
Answer: Responses should include a discussion of collagen accumulation, calcification, cholesterol and plaque,
valvular changes, and endothelial linings.
RELATED DISEASES OF HOMEOSTATIC INSTABILITY
1. Hypertension—Commonly referred to as “high blood pressure,” it may become a chronic condition that
overworks the heart. The left ventricle may enlarge, resulting in heart failure. Treatment includes diet, exercise,
smoking cessation, and medication.
2. Cor Pulmonale—Sometimes secondary to another disease, it is caused by a failure of the right ventricle,
resulting in pulmonary hypertension. The right ventricle overworks, hypertrophies, dilates, and fails, possibly
due to chronic lung disease.
3. Tetralogy of Fallot—A condition in which four defects occur together: pulmonary stenosis, ventricular septal
defect, right ventricular hypertrophy, and an overriding aorta. Typical symptoms include the evidence of a
“blue baby.” Surgery is usually indicated.
SUGGESTIONS FOR ADDITIONAL READING
Folkman, Judah. September 1996. Fighting Cancer by Attacking Its Blood Supply. Scientific American.
Lakka, Timo A., et al. June 2, 1994. Relation of leisure-time physical activity and cardiorespiratory fitness to the risk
of acute myocardial infarction in men. New England Journal of Medicine, vol. 330.
Lewis, Ricki. May 1990. Cardiovascular spare parts. FDA Consumer. Artificial hearts, blood, and blood vessels can
be teamed with preventative measures to build a better cardiovascular system.
Lindpainter, Klaus. June 9, 1994. Genes, hypertension, and cardiac hypertrophy. New England Journal of Medicine,
vol. 330. Researchers are uncovering genetic clues to cardiovascular disease.
Lüscher, T.F. April 14, 1994. The endothelium and cardiovascular disease. New England Journal of Medicine, vol.
330. The state of the endothelium that lines blood vessels is important in cardiovascular health.
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