MATERIALS AND RESOURCES lesson plan textbook artificial blood prepared blood smears including sickle-cell anemia slides

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1 16 Lesson Plan Blood TEACHING FOCUS This chapter begins a new unit. In this unit, the student will have the opportunity to examine the transportation system of the body. It is important to emphasize to students that homeostasis of the internal environment (and therefore survival itself) depends on continuous transportation to and from body cells. This chapter examines the primary functions of blood, the characteristics of blood plasma, and the functions of the formed elements. Students will also have the opportunity to learn the steps involved in blood clotting and a description of ABO and Rh blood typing. MATERIALS AND RESOURCES lesson plan textbook artificial blood prepared blood smears including sickle-cell anemia slides LESSON CHECKLIST Preparations for this lesson include: Lecture Guest speakers: phlebotomist, hematologist, or a representative from a community blood bank Student performance evaluation of all entry-level skills required for student comprehension and application of anatomy and physiology of blood plasma and blood components. KEY TERMS agglutinate (p. x agranulocyte (p. x anemia (p. x anticoagulant drug (p. x antigen (p. x antigen A (p. x antigen B (p. x antiplatelet drug (p. x B lymphocyte (p. x basophil (p. x blood boosting (p. x blood doping (p. x blood serum (p. x blood type (p. x complete blood cell count (CBC) (p. x coumarin (p. x diapedesis (p. x differential white blood cell count (p. x electrolyte (p. x eosinophil (p. x erythroblastosis fetalis (p. x erythrocyte (p. x erythropoiesis (p. x erythropoietin (p. x extrinsic pathway (p. x fibrinolysis (p. x formed element (p. x globin (p. x granulocyte (p. x hematocrit (p. x hemocytoblast (p. x hemoglobin (p. x hemolysis (p. x hemostasis (p. x heparin (p. x intrinsic pathway (p. x leukocyte (p. x leukocytosis (p. x leukopenia (p. x lymphocyte (p. x monocyte (p. x myeloid tissue (p. x neutrophil (p. x nonelectrolyte (p. x physiological polycythemia (p. x plasma (p. x plasminogen (p. x platelet (p. x platelet plug (p. x prothrombin (p. x Rh antigen (p. x streptokinase (p. x T lymphocyte (p. x thrombopoiesis (p. x thrombosis (p. x transfusion reaction (p. x whole blood volume (p. x ADDITIONAL RESOURCES PowerPoint slides (DVD, Evolve): 1-40 Study Guide A&P Online Asset Library Animations

2 190 Chapter 16 Blood

3 Chapter 16 Blood 191 LESSON 16.1 PRETEST 1. The measurement of the plasma and formed elements is typically expressed as a percent of the: a. blood volume. c. maximum blood volume. b. whole blood volume. d. blood volume ratio. 2. Which is NOT a formed element of blood? a. erythrocyte c. albumin b. platelet d. leukocyte 3. An adult male who has a hemoglobin content of less than 10 g/100 ml of blood is diagnosed as having: a. leukemia. c. hemophilia. b. leukopenia. d. anemia. 4. Which of the following is NOT classified as a granulocyte? a. monocyte c. neutrophil b. basophil d. eosinophil 5. The cytoplasmic granules of basophils contain: a. histamine. c. heparin. b. antihistamine. d. both a and c. 6. What cell serves as the precursor of erythrocytes, leukocytes, and platelets? a. myeloid cell c. T cell b. hematopoietic stem cell d. B cell 7. Within 1 to 5 seconds after injury to a blood capillary, a is formed when platelets adhere to the damaged wall of the vessel. a. platelet net c. plug b. platelet clot d. constrictor 8. Because type O blood contains neither antigen A nor B, it has often been called: a. universal donor. c. an agglutinator. b. universal recipient. d. a coagulator. 9. Plasma consists of: a. water. c. electrolytes. b. proteins. d. all of these are correct. 10. The pale yellowish liquid left after a clot forms is: a. plasma. c. prothrombin. b. blood serum. d. fibrin. Answers 1. b 2. c 3. d 4. a 5. d 6. b 7. c 8. a 9. d 10. b BACKGROUND ASSESSMENT Question: Identify the cells that comprise the formed elements of blood. Answer: Red blood cells (RBCs, erythrocytes), white blood cells (WBCs, leukocytes), and platelets (thrombocytes).

4 192 Chapter 16 Blood Question: What is the importance of a differential WBC count as a diagnostic tool? Answer: The number of each type of white blood cell can be determined by a differential WBC count. In this special count, the proportion of each type of white blood cell is reported as a percentage of the total WBC count. Because all disorders do not affect each type of WBC the same way, the differential WBC count is a valuable diagnostic tool. CRITICAL THINKING QUESTION What approach would you use to develop a natural, legal way to perform blood doping (increase RBCs) before an athletic competition? Guidelines: Many athletes increase their RBCs by training at a high-altitude facility. The decreased oxygen availability at a higher elevation stimulates the release of erythropoietin, which increases erythropoiesis and produces physiological polycythemia. OBJECTIVES CONTENT TEACHING RESOURCES 1. Summarize the basic Blood Composition (p. PPT: 4 functions of SG questions: 5, 17, 20 (p. blood. EILR TB: T/F: 63; MC: 14, 38 Outline Summary: Introduction (p. 2. Describe the components of blood and discuss their functions. 3. List the formed elements of blood and discuss their functions. Blood Composition (p. Formed Elements of Blood (p. Red Blood Cells (Erythrocytes) (p. White Blood Cells (Leukocytes) (p. Platelets (Thrombocytes) (p. Class Activity Ask students to write down the functions of blood and have them discuss how these functions maintain homeostasis. PPT: 5, 6 SG questions: 9, 10, 19, 24 (p. EILR TB: T/F: 1, 2, 41; MC: 22, 43 Figure: 16-1 (p. Quick Check question: 1 (p. Outline Summary: Blood Composition (p. Class Activity Arrange the students in groups and have them write down all of the components of blood. Allow them time to then write down what each component does. Have the students present their findings to the class. PPT: 7-10; 15-23; SG questions: 2-4, 11, 13, 16, 18, 29, (p. EILR TB: T/F: 4, 5, 12, 13, 31, 39, 43, 45-47, 64, 83, 87; MC: 3-8, 15, 33-35, 39, 42, 45; S/A: 1, 13 Figure: 16-3 (p. Quick Check question: 2 (p. Outline Summary: Formed Elements of Blood (p.

5 Chapter 16 Blood 193 OBJECTIVES CONTENT TEACHING RESOURCES Review Question: 1 (p. CTQ 1 (p. Class Activities If students have already read the chapter, allow them 10 to 15 minutes to collaborate, in small groups, in creating a table or chart that lists the types of blood cells normally found in circulating blood and that identifies the most important function of each. Have each group share their chart with the rest of the class. 4. Discuss the origin and significance of sickle cell anemia in the world. 5. Outline the formation of erythrocytes, leukocytes, and thrombocytes from the stem cell hemocytoblast. 6. Discuss how blood doping could be dangerous. Formed Elements of Blood (p. Red Blood Cells (Erythrocytes) (p. Hemoglobin (p. Formed Elements of Blood (p. Red Blood Cells (Erythrocytes) (p. Formation of Red Blood Cells (p. White Blood Cells (Leukocytes) (p. Formation of White Blood Cells (p. Platelets (Thrombocytes) (p. Formation and Life Span of Platelets (p. Formed Elements of Blood (p. Red Blood Cells (Erythrocytes) (p. Formation of Red Blood Cells (p. Divide the class into lab groups. Using blood smear slides, allow the students to view the slides and identify the RBCs. PPT: 10 SG question: 15 (p. EILR TB: T/F: 66, 76; S/A: 2 Figure: 16-2 (p. Outline Summary: Formed Elements of Blood (p. Class Activity Provide students with prepared slides depicting sickle-cell anemia. Have them compare them to normal blood smears. PPT: 11-13; 24, 28 SG questions: 6-8, 21-23, 28, 49, 53, 54 (p. EILR TB: T/F: 10, 14, 32-34, 48, 49, 51, 54, 75, 81, 82; MC: 9-11; MATCH: 1-5; 30-38; S/A: 4, 12, 14, 21, 22 Figures: 16-4, 16-5 (p. Quick Check questions: 7, 8 (p. Outline Summary: Formed Elements of Blood (p. Review Question: 5 (p. Class Activity Have the students develop a concept map illustrating the formation of all blood cells. PPT: 11 EILR TB: T/F: 6; S/A: 3 Outline Summary: Formed Elements of Blood (p.

6 194 Chapter 16 Blood OBJECTIVES CONTENT TEACHING RESOURCES CTQ 5 (p. 7. List the different leukocytes and describe their functions. Formed Elements of Blood (p. White Blood Cells (Leukocytes) (p. Granulocytes (p. Agranulocytes (p. Class Activity Provide students with background information regarding blood doping among competitive athletes. Have them discuss how athletes can legally boost their RBCs or erythropoietin levels. PPT: SG questions: 25, 26, 30-46, 48, 55, 56, (p. EILR TB: T/F: 7-9, 11, 54-56, 69, 73, 74, 84-86; MC: 13, 14, 17-20, 46-49; MATCH: 6-15; S/A: 19, 20 Figures: (p. Quick Check question: 9 (p. Outline Summary: Formed Elements of Blood (p. Review Question: 7 (p. Class Activity Divide the class into lab groups. Provide students with a prepared blood smear and have them perform a differential WBC count Homework/Assignments: 16.1 Instructor s Notes/Student Feedback: LESSON 16.2 CRITICAL THINKING QUESTION Mrs. Emery is pregnant. Her blood type is O negative and her husband s blood type is O positive. She has been told that she will need to receive RhoGAM during her pregnancy (between 26 and 28 weeks) and again at delivery if the baby has O positive blood. She feels that it is important to receive as few medications as possible during her pregnancy. How should you advise her? Guidelines: The red blood cells of a person with Rh-negative blood do not contain the Rh factor. Plasma does not naturally contain anti-rh antibodies. However, if Rh-positive blood cells are introduced into the Rh-

7 Chapter 16 Blood 195 negative person s body, anti-rh antibodies will soon appear. This can happen if a woman with Rh-negative blood is carrying a fetus with Rh-positive blood or if a person with Rh-negative blood receives a transfusion of Rh-positive blood. In the case of pregnancy, if Rh-positive blood mixes with the Rh-negative blood, the mother s body will form anti-rh antibodies. Then, if she later carries another Rh-positive fetus, the fetus might have a disease called erythroblastosis fetalis, caused by the mother s Rh antibodies reacting with the baby s Rhpositive cells. For this reason, all Rh-negative mothers who carry an Rh-negative baby must be treated with RhoGAM, which stops the mother s body from forming anti-rh antibodies. OBJECTIVES CONTENT TEACHING RESOURCES 8. Describe in Blood Types (Blood Groups) (p. PPT: 29, 30 detail the ABO blood group The ABO System (p. SG questions: 62, (p. system and EILR TB: T/F: 15-18, 35-37, 59, 88-90; discuss its significance. MC: 24, 36, 50-52; MATCH: 16-20; S/A: 5, 6, 10; S/A: 23; OTHER Figures: (p. Quick Check questions: 11, 13 (p. Outline Summary: Blood Types (Blood Groups) (p. Review Question: 9 (p. CTQ 2 (p. Class Activities Using synthetic blood obtained from a biological supply company, have students type the blood and demonstrate how the antibodies can act on the different types of blood. 9. Discuss the physiological significance of the Rh system. Blood Types (Blood Groups) (p. The Rh System (p. Invite a representative from a community blood bank to discuss issues with blood typing and answer students questions about blood donation. PPT: 31, 32 EILR TB: T/F: 19, 38, 60; MC: 23; S/A: 11; OTHER: 1 Figure: (p. Quick Check question: 12 (p. Outline Summary: Blood Types (Blood Groups) (p. Review Question: 9 (p. CTQ 6 (p. Class Activity Break the class into three groups and assign the following topics: surgical glue, artificial blood, and erythropoietin. If an Internet connection is available, ask students to use a computer to research their topic and present their findings to the class.

8 196 Chapter 16 Blood OBJECTIVES CONTENT TEACHING RESOURCES 10. List the major Blood Plasma (p. PPT: components of SG questions: 1, 14, 63, 64, 88, 95, 96 (p. blood plasma. EILR TB: T/F: 20-26, 40, 61, 62; MC: 25; S/A: Outline the basic mechanism of blood clotting. Performance Evaluation Blood Clotting (Coagulation) (p. Outline Summary: Blood Plasma (p. Review Questions: 11, 12 (p. PPT: SG questions: 47, 50-52, 65-76, 89-94, (p. EILR TB: T/F: 27-29, 50, 57, 58, 71, 72, 91, 92; MC: 21, 26-31, 37, 53-55; MATCH: 21-29; S/A: 8, 9, 23, 24; OTHER: 2 Figure: (p. Quick Check question: 14 (p. Outline Summary: Blood Clotting (Coagulation) (p. Review Questions: (p. CTQ 3, 4 (p. Class Activities Divide the class into lab groups. Using blood smear slides, allow the students to identify platelets. Using Figure (p. as a guide, ask a student to volunteer to explain the process of blood clotting to the class. SG questions: 1-99 (p. Figures: (p. Quick Check questions: 1-14 (p. Review Questions: 1-16 (p. CTQ 1-6 (p.

9 Chapter 16 Blood Homework/Assignments: 16.2 Instructor s Notes/Student Feedback:

10 198 Chapter 16 Blood ANSWERS TO CHAPTER 16 TEXTBOOK QUESTIONS Introductory Story Questions 1. C Plasma is the liquid portion of blood. By itself, plasma is a clear, straw-colored liquid. This liquid constitutes about 55% of our blood. 2. B As soon as tissue damage occurs, the platelets in the bloodstream become sticky. They will stick to both the torn vessel lining and to themselves, quickly forming a plug to limit the blood loss. 3. A The clotting cascade is a series of chemical reactions that require different chemicals (factors) at specific points in the process. The final step in the process is the conversion of soluble fibrinogen to nonsoluble fibrin, which acts as a meshwork for trapping blood cells and thereby seals off the gap to allow healing to begin. 4. D Hemophilia A is a condition in which factor VIII is missing from the body. Without this factor, the coagulation process cannot be completed. Thrombocytopenia is a drop in platelet count. This will also affect the body s ability to form a clot, but at the first step of the process (forming the platelet plug). Review Questions 1. The formed elements of blood are RBCs, WBCs, and platelets. 2. Carbonic anhydrase is the enzyme that catalyzes the joining of carbon dioxide and water to form carbonic acid. 3. Each hemoglobin molecule is composed of four protein chains called globins. Each globin is joined to a molecule of heme, and each heme molecule contains one atom of iron. 4. Oxygen is able to combine with the heme portion of hemoglobin. Therefore one molecule of hemoglobin can combine with four molecules of oxygen. 5. Erythropoiesis begins with the differentiation of stem cells into proerythroblasts, which divide to form basophilic erythroblasts. These become polychromic erythroblasts, which form hemoglobin. These cells then lose their nuclei and become reticulocytes. Reticulocytes are released into the blood and mature into erythrocytes in about 24 to 36 hours. 6. The average life span of an RBC in the bloodstream is about 105 to 120 days. 7. Granulocytes contain granules in their cytoplasm, whereas agranulocytes do not. All WBCs have nuclei and are usually larger than RBCs. 8. Platelets have three important physical properties: agglutination, adhesiveness, and aggregation. 9. Type AB blood has both A and B antigens on the RBCs and neither A nor B antibodies in the plasma. Rh-negative blood has no Rh antigens on the RBCs. 10. The liver is responsible for the synthesis of most plasma proteins. 11. In 100 ml of plasma, there are 6 to 8 grams of plasma protein. Of this, 55% is albumin, 38% is globulins, and 7% is fibrinogen. 12. Fibrinogen is important in blood clot formation. Globulins are important in immunity. All plasma proteins contribute to normal blood viscosity, blood osmotic pressure, and blood volume. 13. In hemostasis, a few seconds after injury to a capillary, platelets will adhere to the damaged lining and to one another, forming a platelet plug that helps stop the flow of blood to the tissue. In blood clot formation, platelets participate in the intrinsic pathway by releasing platelet factor VIII. This substance activates factor X, which then produces prothrombinase, a prothrombin activator. 14. Factors that oppose blood clotting include the perfectly smooth surface of normal endothelial lining of the blood vessels; antithrombins in the blood; and coumarin compounds, which impair the liver s utilization of vitamin K. Factors that hasten blood clotting include rough spots on the epithelial linings of blood vessels and body immobility. 15. There are two triggers to blood clotting. In the extrinsic clotting pathway, chemicals released from damaged tissue outside the blood system trigger blood clotting. In the intrinsic clotting pathway, damage to the endothelial lining of the blood vessels, which exposes collagen fibers, triggers blood clotting. 16. Anemia: An inability of the blood to carry sufficient oxygen to the body. Polycythemia: Bone marrow produces an excess of RBCs. Aplastic anemia: Abnormally low number of RBCs. Pernicious anemia: Another disorder characterized by low RBCs. Folate deficiency: Similar to pernicious anemia in that RBC numbers are low; brought on by a vitamin deficiency.

11 Chapter 16 Blood 199 Hemolytic anemia (sickle-cell anemia, thalassemia): Inherited blood disorders characterized by abnormal types of hemoglobin. Leukocytosis: Abnormally high WBC count. Hemophilia: X-linked inherited blood disorder that affects blood clotting. Thrombocytopenia: clotting disorder. Critical Thinking Questions 1. Hematocrit is the volume percentage of RBCs in whole blood. One of the ways hematocrit can be determined is to allow whole blood to separate. This can be done rapidly by putting the blood into a centrifuge. The normal hematocrit value is 45%; the normal range is between 38% and 52%. If your friend s hematocrit was below 38%, it would be below normal. 2. The most likely cause would be a blood transfusion with an incompatible blood type. The antibodies in the transfused blood reacted with the antigens in the receiver s blood to cause the agglutination. 3. The hormone calcitonin causes a reduction in the blood calcium level. The calcium ion is necessary in the blood for the final two steps in the formation of fibrin for blood clot formation. A serious drop in the blood calcium levels would hinder these reactions and slow the blood clotting time. 4. The following steps could be taken to speed up clot formation: applying a rough surface, applying heat, squeezing the tissue around the cut to stimulate platelets to release platelet factor, applying purified thrombin to speed up the conversion of fibrinogen to fibrin, and applying fibrin directly to the cut. 5. Blood doping is a practice where athletes have blood drawn a few weeks before competition. The RBCs are then separated and frozen. Just before competition, the RBCs are thawed and injected back into the athlete. Theoretically, the increased number of RBCs and hemoglobin would increase the oxygen consumption and muscle performance during exercise. The effects are minimal, and the risk of affecting viscosity of blood may have harmful effects on the athlete. 6. Erythroblastosis fetalis occurs when an Rh-negative mother forms anti-rh antibodies from one or more Rh-positive pregnancies. These antibodies enter the baby s blood and cause agglutination of the RBCs. ADDITIONAL PRACTICAL/CREATIVE LEARNING ACTIVITIES Before beginning this unit, refer to the Evolve website for additional resource materials. Incorporate use of the dialectical journal. A good way to begin discussion of any chapter and to stimulate a vested interest in the material is by writing predictions. Begin this chapter by asking students to draw a line vertically down the center of one or two notebook pages and then to write predictions in the lefthand column about the following (leaving plenty of space before and after each): a. Predict the generalized function of blood. b. Without looking ahead, how many types of blood cells can you name? c. What exactly is hemoglobin? d. What do you think is the function of platelets? e. Predict the results of abnormally high or low counts of each of the three blood cell types. f. How many blood types are there? What is your own? g. Predict which blood types a given ABO blood type can safely donate to or receive from. Next instruct the students that, as they progress through the chapter, they should respond to and correct their predictions in the right-hand column of their notebook. This strategy reinforces new knowledge by creating a preliminary knowledge base through predictions. Students may not be used to thinking in metric terms. To help them visualize metric measurements, show a paper clip to represent a gram in weight, a dime to demonstrate a millimeter in thickness, and a quart bottle to show an approximate liter. Point out blood cell production sites on an articulated skeleton. Compare a beaker solution (crystalloids) to a colloid suspension. Demonstrate hematocrit in heparinized capillary tube, coagulation time with nonheparinized capillary tube, and hemoglobin estimation by color chart match. Assign students to research the use of adult stem cells in bone marrow transplant procedures. DIFFICULT CONCEPTS

12 200 Chapter 16 Blood The Number of Cells in a Cubic Millimeter Using a metric ruler, show the students the size of a cubic millimeter. Then discuss with them the number of RBCs, WBCs, and thrombocytes in that space, also giving the percentage that is cell and the percentage that is plasma. It is difficult to imagine that large a number of cells in such a small space. Then carry this calculation on to the number of cells in a liter and, finally, in the blood volume of an average human. Hematocrit The concept of how the centrifuge packs the cells, giving the packed cell volume (PCV) of hematocrit, can be illustrated by the example of swinging someone around by his or her arms. The faster you spin, the farther the centrifugal force pulls the person from you. The heavier the person is, the greater the pull on you. That is why adults swing children who are little, and do this less and less as the child gets larger. There is too much centrifugal force in a large object. The blood cells weigh more than the plasma, and they move to the outer end of the spinning tube. Rh Typing Students seem to grasp ABO typing but often are confused by Rh typing. Emphasize that it does not matter whether the Rh factor is present on the RBC (Rh-positive) or is absent from the RBC (Rh-negative) the plasma does not have the anti-rh agglutinin. The Rh-positive person will not have the anti-rh agglutinin. The Rh-negative person may start producing the anti-rh agglutinin if exposed to the Rh factor through transfusion (or across the placenta, as in a woman who is Rh-negative and is pregnant with an Rh-positive fetus). Then point out that an Rh-negative fetus in an Rh-positive mother is in no danger, since the mother cannot produce anti-rh agglutinins and the fetus cannot have Rh agglutinogens on the RBCs. An Rh-negative mother carrying an Rh-positive fetus presents a problem to the fetus, because some of the fetal blood will mix with the mother s blood and she will start producing anti-rh agglutinins, which will cross the placental wall and start to agglutinate the fetus s RBCs. Agglutination and Coagulation Students often confuse these two functions. They must be reminded that agglutination refers to the RBCs sticking to one another, or clumping together. Coagulation, on the other hand, is the process of forming a fibrin clot. Agglutination is analogous to everyone in the class holding hands with three or four other people and then trying to go out the door. They form a big clump of humanity that will not fit through the door. Coagulation is similar to placing a series of bars across the door. As people try to leave, they get stopped by the bars, which represent the fibrin of the clot. CLINICAL APPLICATIONS Sickle Cell Anemia (Box 16-1) Use this box to stimulate discussion on the mechanisms of sickle cell anemia and how this condition might influence normal functions of the blood. Blood Doping (Box 16-2) Use this box to stimulate discussion by asking students to suggest possible risks associated with this practice. Complete Blood Count (Box 16-3) Point out that this is not just one test (as patients often assume) but rather a battery of tests, which, when evaluated together, provide an encompassing picture of a person s overall health. You may want to assign individuals or pairs of students to prepare descriptions of the individual tests within this battery (e.g., RBC, WBC, thrombocyte counts, differential WBC count, hematocrit, hemoglobin content).

13 Chapter 16 Blood 201 Anticoagulant Versus Antiplatelet Drug Treatment (Box 16-4) Different types of drug treatment for conditions caused by venous or arterial thrombi are described in this box. Clinical Methods of Hastening Clotting (Box 16-5) This box outlines three ways to speed clotting. Blood Transfusions (A&P Connect) This link discusses homologous transfusions and autologous transfusions. Also addressed is the reinfusion of a patient s blood during surgery and the converting of one type of blood to another.