Unit 5

Circulatory System

Understandings

• The structures and functions within the Cardiovascular System.

• Develop an understanding of the cells which make up blood and their function.

• Understanding diseases and the developmental aspects related to blood and the Cardiovascular System.

Essential Questions

• How does blood serve as a vehicle for distributing the body’s heat and for transporting nutrients, respiratory gases, and other substances throughout the body?

• What are the structures and the functions of the heart and the blood vessels in the body’s circulatory system?

Key Concepts / Skills

1. Structure and function of the Heart

2. Identifying cells which makeup blood and their function.

3. Function of Blood Vessels.

4. Developmental aspects and diseases associated with cardiovascular system.

5. Developmental aspects and diseases associated with blood.

Assessments

• Performance based Assessment (PBA) – Preparation and participation in a lab practical exam.

• Lab report, worksheet, discussion, test

Standards

LS1 Describe the composition and functions of blood.

LS1 Describe the location of the heart in the body, identify its major anatomical areas on an appropriate model, trace the

pathway of blood through the heart, explain the operation of the heart valve, and compare the pulmonary and systemic

circuits.

LS1 Compare and contrast the structures and functions of the body’s arteries, veins, and capillaries with special attention to

the unique features of the: arterial circulation of the brain, hepatic portal circulation, and fetal circulation.

LS1 Define blood pressure and pulse and the conditions which can affect either.

LS4 Describe the developmental aspects and the disorders associated with the cardiovascular system.

Common Misconceptions

1. In CHF, blood pumped to the lungs by the right ventricle does not keep pace with blood pumped around the system by the left ventricle. Fluid builds up in the lungs, leading to the predominant symptom of CHF, which is breathing difficulty.

2. 5–6 liters/minute is the average resting cardiac output for an average healthy adult male.

3. In differentiating between arteries, veins, and capillaries, emphasize that the structure of each type of vessel is related to the differing amounts of pressure they must each absorb from the heart, as well as their respective roles in blood transport.

4. Dispel the notion of good and bad cholesterol, and instead to help students understand that moderation is key to a healthy cardiovascular system. Point out that the lymphatic system dumps fats into the vena cavae immediately before blood returns to the heart.

5. Through advertising, students are usually quite familiar with nutritional substitutes, such as fat and sugar substitutes, but they often don’t understand the mechanisms at play and the potential side effects from the use of these substitutes.

6. Students are usually familiar with the illness described as “strep throat,” but often are unaware of its serious ramifications.

7. Compare the body’s self-regulating pacemaker, the SA node, to an artificial pacemaker in function and performance. Describe the 1,000,000 or more times each week that the heart’s pacemaker fires and causes it to pump blood around the system and back again to the heart.

8. The only function of the valves of the heart is to ensure the one-way flow of blood. Explore with the students the consequences of incompetent or stenotic valves.

9. The pulmonary arteries carry deoxygenated blood from the right side of the heart to the lungs, and the pulmonary veins return oxygenated blood to the left side of the heart.

10. In discussing fetal circulation, point out that all fetuses have a “hole in their heart,” and in fact two holes, which allow circulation to be routed around the non-inflated lungs. Explain the fact that if these “holes” don’t close at or shortly after birth, then surgical closure is required, usually to correct a PDA (patent ductus arteriosus).

11. Describe the various methods that can be used to treat atherosclerosis (e.g., stents, angioplasty).

12. Discuss smoking and its cardiovascular implications, including arteriovascular insufficiency, ischemia, intermittent claudication with concomitant leg pain and cramps, thrombus formation, and impotence.

13. Differentiate between myocardial infarction, stroke, pulmonary embolism, and thrombi. Students often do not realize that these terms can all be related to one another since they refer to blockage of blood vessels in different parts of the body.

14. Explain the difference between an aneurysm and a ruptured aneurysm. The media often does not distinguish between these two terms, so students can get confused as to their effects and treatment.

Suggested Learning Activities

1. Mink dissection

2. Vernier Experiment # 27, Heart Rate and Physical Fitness

3. Vernier Experiment # 28, Monitoring EKG

Books and Materials

1. Essentials of Human Anatomy & Physiology, Pearson

2. Anatomy & Physiology Coloring Book, Pearson

3. A Dissection guide and Atlas to the Mink, Morton Publishing Company

4. Vernier Biology with Computer Labs