Chapter 24 The Immune System.

Chapter 24 The Immune System

Introduction Neutrophils are a kind of white blood cell,
Neutrophils are a kind of white blood cell, capable of recognizing and destroying foreign invaders, and part of the body’s immune system. © 2012 Pearson Education, Inc. 2

Introduction The human body’s immune system
The human body’s immune system recognizes agents that cause disease and attacks them. © 2012 Pearson Education, Inc. 3

Disorders of the Immune System
Figure 24.0_1 Chapter 24: Big Ideas Innate Immunity Adaptive Immunity Figure 24.0_1 Ch 24: Big Ideas Disorders of the Immune System 4

Figure 24.0_2 Figure 24.0_2 Neutrophil engulfing four bacteria 5

24.1 All animals have innate immunity
Nearly everything in the environment teems with pathogens, agents that cause disease. The immune system is the body’s system of defenses against agents that cause disease. Innate immunity is a series of defenses that act immediately upon infection and are the same whether or not the pathogen has been encountered before. Student Misconceptions and Concerns Students may be frustrated by the amount of detail about the immune system provided in this chapter, and struggle to organize information about the many types of cells and responses. Asking them to create or complete tables, similar to the one in Figure 24.1, can help your students manage the information presented in the textbook and in your class discussions. Teaching Tips 1. Students might be interested to learn that interferons are now mass-produced using recombinant DNA technology. Clinical studies are under way to explore their use in treating viral infections and cancer. 2. In an interesting article on the effectiveness of common hygiene methods, “Hygiene of the Skin: When Is Clean Too Clean?” Elaine Larson reviews the relationship between skin hygiene and infection. It can be found at the CDC website at © 2012 Pearson Education, Inc. 7

Invertebrates rely solely on innate immunity, which may consist of an exoskeleton, low pH, the enzyme lysozyme, and immune cells capable of phagocytosis, cellular ingestion and digestion of foreign substances. Vertebrates have innate and adaptive immunity. Student Misconceptions and Concerns Students may be frustrated by the amount of detail about the immune system provided in this chapter, and struggle to organize information about the many types of cells and responses. Asking them to create or complete tables, similar to the one in Figure 24.1, can help your students manage the information presented in the textbook and in your class discussions. Teaching Tips 1. Students might be interested to learn that interferons are now mass-produced using recombinant DNA technology. Clinical studies are under way to explore their use in treating viral infections and cancer. 2. In an interesting article on the effectiveness of common hygiene methods, “Hygiene of the Skin: When Is Clean Too Clean?” Elaine Larson reviews the relationship between skin hygiene and infection. It can be found at the CDC website at © 2012 Pearson Education, Inc. 8

• Mucous membranes • Hairs • Cilia • Phagocytic cells
Figure 24.1A Innate immunity (24.1–3) The response is the same whether or not the pathogen has been previously encountered Adaptive immunity (24.4–15) Found only in vertebrates; previous exposure to the pathogen enhances the immune response External barriers (24.1) Internal defenses (24.1–2) • Skin/ exoskeleton • Acidic environment • Secretions • Mucous membranes • Hairs • Cilia • Phagocytic cells • NK cells • Defensive proteins • Inflammatory response (24.2) • Antibodies (24.8–10) • Lymphocytes (24.11–13) Figure 24.1A An overview of animal immune systems The lymphatic system (24.3) 9

Vertebrate innate immunity includes barriers such as skin and mucous membranes, interferons, proteins produced by virus-infected cells, that help to limit the cell-to-cell spread of viruses, neutrophils (phagocytic cells), macrophages, large phagocytic cells that wander through the interstitial fluid, natural killer cells that attack cancer cells and virus-infected cells, and a complement system, a group of about 30 kinds of proteins that can act with other defense mechanisms. Student Misconceptions and Concerns Students may be frustrated by the amount of detail about the immune system provided in this chapter, and struggle to organize information about the many types of cells and responses. Asking them to create or complete tables, similar to the one in Figure 24.1, can help your students manage the information presented in the textbook and in your class discussions. Teaching Tips 1. Students might be interested to learn that interferons are now mass-produced using recombinant DNA technology. Clinical studies are under way to explore their use in treating viral infections and cancer. 2. In an interesting article on the effectiveness of common hygiene methods, “Hygiene of the Skin: When Is Clean Too Clean?” Elaine Larson reviews the relationship between skin hygiene and infection. It can be found at the CDC website at © 2012 Pearson Education, Inc. 10

Antiviral proteins block viral reproduction Virus
Figure 24.1B Viral nucleic acid Antiviral proteins block viral reproduction Virus 1 New viruses 2 Interferon genes turn on DNA mRNA 3 5 Interferon molecules Interferon stimulates cell to turn on genes for antiviral proteins Figure 24.1B The interferon mechanism against viruses 4 Host cell 1 Host cell 2 Makes interferon; is killed by the virus Is protected against the virus by interferon from cell 1 11

24.2 Inflammation mobilizes the innate immune response
Tissue damage triggers the inflammatory response, a major component of our innate immunity, which can disinfect and clean infected tissues and limit the spread of infection to surrounding tissues. Bacterial infections can bring about an overwhelming systemic inflammatory response leading to septic shock, characterized by very high fever and low blood pressure. Student Misconceptions and Concerns Students may be frustrated by the amount of detail about the immune system provided in this chapter, and struggle to organize information about the many types of cells and responses. Asking them to create or complete tables, similar to the one in Figure 24.1, can help your students manage the information presented in the textbook and in your class discussions. Teaching Tips 1. The inflammatory response described in Module 24.2 and characterized in Figure 24.2 provides a good student hook for this chapter. The inflammatory response is a reaction that is immediately apparent, with characteristics that can cause alarm. Students are typically more interested in subjects that have obvious relevance to their lives, including potential threats to their health! 2. Excessive amounts of iron in the human body can promote bacterial infections and other disease. Searching for the key words iron supplements bacteria on the CDC website at will turn up many articles on this subject. © 2012 Pearson Education, Inc. 12

Figure 24.2 The inflammatory response
Pin Skin surface Blood clot Swelling Bacteria Phagocytes and fluid move into the area Phagocytes Signaling molecules White blood cell Figure 24.2 The inflammatory response Blood vessel 1 Tissue injury; signaling molecules, such as histamine, are released. 2 Dilation and increased leakiness of local blood vessels; phagocytes migrate to the area. 3 Phagocytes (macrophages and neutrophils) consume bacteria and cellular debris; the tissue heals. 13

Tissue injury; signaling molecules, such as histamine, are released.
Figure 24.2_1 Pin Skin surface Bacteria Signaling molecules White blood cell Figure 24.2_1 The inflammatory response: tissue injury (part 1) Blood vessel 1 Tissue injury; signaling molecules, such as histamine, are released. 14

Phagocytes and fluid move into the area
Figure 24.2_2 Blood clot Swelling Phagocytes and fluid move into the area Figure 24.2_2 The inflammatory response: phagocyte migration (part 2) 2 Dilation and increased leakiness of local blood vessels; phagocytes migrate to the area. 15

Figure 24.2_3 Phagocytes Figure 24.2_3 The inflammatory response: phagocytes consume bacteria (part 3) 3 Phagocytes (macrophages and neutrophils) consume bacteria and cellular debris; the tissue heals. 16

24.3 The lymphatic system becomes a crucial battleground during infection
The lymphatic system is involved in innate and adaptive immunity and consists of a network of lymphatic vessels, lymph nodes, and lymph. Student Misconceptions and Concerns Students may be frustrated by the amount of detail about the immune system provided in this chapter, and struggle to organize information about the many types of cells and responses. Asking them to create or complete tables, similar to the one in Figure 24.1, can help your students manage the information presented in the textbook and in your class discussions. Teaching Tips 1. Excessive amounts of iron in the human body can promote bacterial infections and other disease. Searching for the key words iron supplements bacteria on the CDC website at will turn up many articles on this subject. 2. During a medical examination, a physician might feel for tenderness in the throat, axillary (armpit), and inguinal (groin) regions. Students are unlikely to appreciate the significance of this part of the exam. Making this connection for them can add relevance to your class discussions and generate additional interest in the subject. © 2012 Pearson Education, Inc. 17

Lymphatic vessels collect fluid from body tissues and return it as lymph to the blood. Lymph organs include the spleen and lymph nodes and are packed with white blood cells that fight infections. Student Misconceptions and Concerns Students may be frustrated by the amount of detail about the immune system provided in this chapter, and struggle to organize information about the many types of cells and responses. Asking them to create or complete tables, similar to the one in Figure 24.1, can help your students manage the information presented in the textbook and in your class discussions. Teaching Tips 1. Excessive amounts of iron in the human body can promote bacterial infections and other disease. Searching for the key words iron supplements bacteria on the CDC website at will turn up many articles on this subject. 2. During a medical examination, a physician might feel for tenderness in the throat, axillary (armpit), and inguinal (groin) regions. Students are unlikely to appreciate the significance of this part of the exam. Making this connection for them can add relevance to your class discussions and generate additional interest in the subject. © 2012 Pearson Education, Inc. 18

As lymph circulates through lymphatic organs it collects microbes, parts of microbes, and microbial toxins, and transports them to lymphatic organs where macrophages in lymphatic organs engulf the invaders and lymphocytes may mount an adaptive immune response. Student Misconceptions and Concerns Students may be frustrated by the amount of detail about the immune system provided in this chapter, and struggle to organize information about the many types of cells and responses. Asking them to create or complete tables, similar to the one in Figure 24.1, can help your students manage the information presented in the textbook and in your class discussions. Teaching Tips 1. Excessive amounts of iron in the human body can promote bacterial infections and other disease. Searching for the key words iron supplements bacteria on the CDC website at will turn up many articles on this subject. 2. During a medical examination, a physician might feel for tenderness in the throat, axillary (armpit), and inguinal (groin) regions. Students are unlikely to appreciate the significance of this part of the exam. Making this connection for them can add relevance to your class discussions and generate additional interest in the subject. © 2012 Pearson Education, Inc. 19

Figure 24.3 Organs Adenoid Lymphatic ducts that drain into veins Lymph node Tonsils Lymph nodes Masses of lymphocytes and macrophages Thymus Lymphatic vessels Valve Lymphatic vessel Spleen Blood capillary Tissue cells Interstitial fluid Appendix Bone marrow Figure 24.3 The human lymphatic system Lymphatic capillary 20

Lymphatic ducts that drain into veins Tonsils
Figure 24.3_1 Organs Adenoid Lymphatic ducts that drain into veins Tonsils Lymph nodes Thymus Lymphatic vessels Spleen Appendix Bone marrow Figure 24.3_1 The human lymphatic system (part 1) 21

Masses of lymphocytes and macrophages
Figure 24.3_2 Lymph node Masses of lymphocytes and macrophages Valve Lymphatic vessel Blood capillary Tissue cells Interstitial fluid Figure 24.3_2 The human lymphatic system (part 2) Lymphatic capillary 22

24.4 The adaptive immune response counters specific invaders
Our immune system responds to foreign molecules called antigens, which elicit the adaptive immune response. The adaptive immune system is found only in the vertebrates, reacts to specific pathogens, and “remembers” an invader. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. 3. The concept of nonspecific and specific defenses is sometimes difficult for students new to the subject. Some analogies, such as the following, might help. Clothing can be considered a general defense against heat loss, minor surface abrasions, and minor chemical damage such as sunburn. Sunscreen is a specific defense, intended to limit exposure to ultraviolet radiation in particular. Teaching Tips The old saying “Give a man a fish and you have fed him for today; teach a man to fish and you have fed him for a lifetime” can be compared to the concept of passive and active immunity. Passive immunity, like the gift of a fish, is temporary. However, active immunity, like the ability to fish, can last a lifetime! © 2012 Pearson Education, Inc. 24

24.4 The adaptive immune response counters specific invaders
Infection or vaccination triggers active immunity. Vaccination, or immunization, exposes the immune system to a vaccine, a harmless variant or part of a disease-causing microbe. We can temporarily acquire passive immunity by receiving premade antibodies. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. 3. The concept of nonspecific and specific defenses is sometimes difficult for students new to the subject. Some analogies, such as the following, might help. Clothing can be considered a general defense against heat loss, minor surface abrasions, and minor chemical damage such as sunburn. Sunscreen is a specific defense, intended to limit exposure to ultraviolet radiation in particular. Teaching Tips The old saying “Give a man a fish and you have fed him for today; teach a man to fish and you have fed him for a lifetime” can be compared to the concept of passive and active immunity. Passive immunity, like the gift of a fish, is temporary. However, active immunity, like the ability to fish, can last a lifetime! © 2012 Pearson Education, Inc. 25

Figure 24.4 Figure 24.4 A soldier receiving a vaccination against the smallpox virus (inset) 26

Figure 24.4_1 Figure 24.4_1 A soldier receiving a vaccination against the smallpox virus (part 1) 27

Figure 24.4_2 Figure 24.4_2 A soldier receiving a vaccination against the smallpox virus (part 2) 28

24.5 Lymphocytes mount a dual defense
Lymphocytes are white blood cells that spend most of their time in the tissues and organs of the lymphatic system, are responsible for adaptive immunity, and originate from stem cells in the bone marrow. B lymphocytes or B cells continue developing in bone marrow. T lymphocytes or T cells develop further in the thymus. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Many analogies can be developed relating to the cells and molecules involved in the immune response. In Module 24.5, the authors note that lymphocytes, which can respond to any antigen, resemble a standing army of soldiers in which each soldier is able to recognize a unique form of the enemy. © 2012 Pearson Education, Inc. 29

B cells participate in the humoral immune response and secrete antibodies into the blood and lymph. T cells participate in the cell-mediated immune response, attack cells infected with bacteria or viruses, and promote phagocytosis by other white blood cells and by stimulating B cells to produce antibodies. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Many analogies can be developed relating to the cells and molecules involved in the immune response. In Module 24.5, the authors note that lymphocytes, which can respond to any antigen, resemble a standing army of soldiers in which each soldier is able to recognize a unique form of the enemy. © 2012 Pearson Education, Inc. 30

Figure 24.5A The development of B cells and T cells
Stem cell Bone marrow Via blood Immature lymphocytes Thymus Antigen receptors Via blood B cell T cell Figure 24.5A The development of B cells and T cells Final maturation of B and T cells in a lymphatic organ Lymph nodes, spleen, and other lymphatic organs Humoral immune response Cell-mediated immune response 31

Via blood Antigen receptors
Figure 24.5A_1 Stem cell Bone marrow Via blood Immature lymphocytes Figure 24.5A_1 The development of B cells and T cells (part 1) Thymus Antigen receptors B cell T cell 32

Final maturation of B and T cells in a lymphatic organ
Figure 24.5A_2 Antigen receptors Via blood B cell T cell Final maturation of B and T cells in a lymphatic organ Lymph nodes, spleen, and other lymphatic organs Figure 24.5A_2 The development of B cells and T cells (part 2) Humoral immune response Cell-mediated immune response 33

Millions of kinds of B cells and T cells each with different antigen receptors, capable of binding one specific type of antigen, wait in the lymphatic system, where they may respond to invaders. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Many analogies can be developed relating to the cells and molecules involved in the immune response. In Module 24.5, the authors note that lymphocytes, which can respond to any antigen, resemble a standing army of soldiers in which each soldier is able to recognize a unique form of the enemy. © 2012 Pearson Education, Inc. 34

Figure 24.5B Figure 24.5B A B cell (left) and T cell (right) 35

24.6 Antigens have specific regions where antibodies bind to them
Antigens are molecules that elicit the adaptive immune response, usually do not belong to the host animal, and are proteins or large polysaccharides on the surfaces of viruses or foreign cells. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips The authors suggest that the specific “fit” between an antigen and an antibody is like the relationship between a lock and a key. You might further this analogy by noting that the tremendous diversity of antibodies is like having a set of keys for virtually every possible type of lock. © 2012 Pearson Education, Inc. 36

24.6 Antigens have specific regions where antibodies bind to them
Antigenic determinants are specific regions on an antigen where antibodies bind. An antigen usually has several different determinants. The antigen-binding site of an antibody and an antigenic determinant have complementary shapes. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips The authors suggest that the specific “fit” between an antigen and an antibody is like the relationship between a lock and a key. You might further this analogy by noting that the tremendous diversity of antibodies is like having a set of keys for virtually every possible type of lock. © 2012 Pearson Education, Inc. 37

Two different antibody molecules
Figure 24.6 Antigen- binding site Two different antibody molecules Antigen molecule Antigenic determinant Figure 24.6 The binding of antibodies to antigenic determinants 38

24.7 Clonal selection musters defensive forces against specific antigens
When an antigen enters the body it activates only a small subset of lymphocytes that have complementary receptors. In clonal selection, the selected lymphocyte cells multiply into clones of short-lived effector cells, specialized for defending against the antigen that triggered the response, and multiply into memory cells, which confer long-term immunity. Plasma cells are the effector cells produced during clonal selection of B cells. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Our own learning experiences provide an analogy to the greater swiftness and intensity of a secondary immune response. When first presented with a problem, we may struggle to determine how best to respond. However, with that first experience behind us, we expect to respond more quickly and effectively when we meet that challenge again. Although in each circumstance we benefit from a certain type of memory (experiential in one case, chemical in the other) their mechanisms are quite different. Consider noting these similarities and differences in your class discussion of primary and secondary immune responses. © 2012 Pearson Education, Inc. 39

The clonal selection of B cells occurs in two responses. In the primary immune response, clonal selection produces effector cells and memory cells that may confer lifelong immunity. In the secondary immune response, memory cells are activated by a second exposure to the same antigen. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Our own learning experiences provide an analogy to the greater swiftness and intensity of a secondary immune response. When first presented with a problem, we may struggle to determine how best to respond. However, with that first experience behind us, we expect to respond more quickly and effectively when we meet that challenge again. Although in each circumstance we benefit from a certain type of memory (experiential in one case, chemical in the other) their mechanisms are quite different. Consider noting these similarities and differences in your class discussion of primary and secondary immune responses. © 2012 Pearson Education, Inc. 40

Animation: Role of B Cells
Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Our own learning experiences provide an analogy to the greater swiftness and intensity of a secondary immune response. When first presented with a problem, we may struggle to determine how best to respond. However, with that first experience behind us, we expect to respond more quickly and effectively when we meet that challenge again. Although in each circumstance we benefit from a certain type of memory (experiential in one case, chemical in the other) their mechanisms are quite different. Consider noting these similarities and differences in your class discussion of primary and secondary immune responses. Animation: Role of B Cells Right click on animation / Click play © 2012 Pearson Education, Inc. 41

Clone of plasma (effector) cells secreting antibodies
Figure 24.7A Primary immune response Secondary immune response 2 Antigen molecules Antigen receptor on the cell surface Antibody molecules 1 B cells with different antigen receptors 3 First exposure to the antigen Cell activation: growth, division, and differentiation Clone of plasma (effector) cells secreting antibodies Antigen molecules Second clone Antibody molecules 4 5 6 Second exposure to the same antigen First clone Figure 24.7A Clonal selection of B cells in the primary and secondary immune responses Endoplasmic reticulum Clone of memory cells Plasma (effector) cells secreting antibodies Memory cells 42

Primary immune response
Figure 24.7A_s1 Primary immune response Antigen receptor on the cell surface B cells with different antigen receptors 1 Figure 24.7A_s1 Clonal selection of B cells: primary response (part 1, step 1) 43

Figure 24.7A_s2 Primary immune response 2 Antigen molecules Antigen receptor on the cell surface B cells with different antigen receptors 1 Figure 24.7A_s2 Clonal selection of B cells: primary response (part 1, step 2) 44

Figure 24.7A_s3 Primary immune response 2 Antigen molecules Antigen receptor on the cell surface B cells with different antigen receptors 1 3 First exposure to the antigen Cell activation: growth, division, and differentiation Figure 24.7A_s3 Clonal selection of B cells: primary response (part 1, step 3) 45

Figure 24.7A_s4 Primary immune response 2 Antigen molecules Antigen receptor on the cell surface B cells with different antigen receptors 1 3 First exposure to the antigen Cell activation: growth, division, and differentiation Antibody molecules Figure 24.7A_s4 Clonal selection of B cells: primary response (part 1, step 4) 4 5 First clone Endoplasmic reticulum Plasma (effector) cells secreting antibodies Memory cells 46

Second exposure to the same antigen
Figure 24.7A_s5 Antigen molecules 6 Second exposure to the same antigen Figure 24.7A_s5 Clonal selection of B cells: secondary response (part 2, step 1) Memory cells 47

Clone of plasma (effector) cells secreting antibodies
Figure 24.7A_s6 Secondary immune response Antibody molecules Antigen molecules Clone of plasma (effector) cells secreting antibodies 6 Second exposure to the same antigen Second clone Figure 24.7A_s6 Clonal selection of B cells: secondary response (part 2, step 2) Clone of memory cells Memory cells 48

Primary vs. secondary immune responses The primary immune response occurs upon first exposure to an antigen and is slower than the secondary immune response. The secondary immune response occurs upon second exposure to an antigen and is faster and stronger than the primary immune response. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Our own learning experiences provide an analogy to the greater swiftness and intensity of a secondary immune response. When first presented with a problem, we may struggle to determine how best to respond. However, with that first experience behind us, we expect to respond more quickly and effectively when we meet that challenge again. Although in each circumstance we benefit from a certain type of memory (experiential in one case, chemical in the other) their mechanisms are quite different. Consider noting these similarities and differences in your class discussion of primary and secondary immune responses. © 2012 Pearson Education, Inc. 49

Second exposure to antigen X, first exposure to antigen Y
Figure 24.7B Second exposure to antigen X, first exposure to antigen Y Secondary immune response to antigen X First exposure to antigen X Antibody concentration Primary immune response to antigen X Primary immune response to antigen Y Figure 24.7B The two phases of the adaptive immune response Antibodies to X Antibodies to Y 7 14 21 28 35 42 49 56 Time (days) 50

24.8 Antibodies are the weapons of the humoral immune response
Antibodies are secreted by plasma (effector) B cells, into the blood and lymph. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Challenge your class to explain the adaptive advantages of antibodies’ Y-shaped structure. Why aren’t antibodies just made up of a single heavy and a single light chain? (Biologists have theorized that the Y shape permits the bonding together of two antigens or antigen-presenting surfaces, allowing a chain reaction or form of clumping.) © 2012 Pearson Education, Inc. 51

Light chain Heavy chain Figure 24.8A
Figure 24.8A A computer graphic of an antibody molecule 52

24.8 Antibodies are the weapons of the humoral immune response
An antibody molecule is Y-shaped and has two antigen-binding sites specific to the antigenic determinants that elicited its secretion. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Challenge your class to explain the adaptive advantages of antibodies’ Y-shaped structure. Why aren’t antibodies just made up of a single heavy and a single light chain? (Biologists have theorized that the Y shape permits the bonding together of two antigens or antigen-presenting surfaces, allowing a chain reaction or form of clumping.) © 2012 Pearson Education, Inc. 53

Antigen-binding sites
Figure 24.8B Antigen Antigen-binding sites V V V V C C Light chain C C Figure 24.8B Antibody structure and the binding of an antigen-binding site to its complementary antigen (enlargement) Heavy chain 54

24.9 Antibodies mark antigens for elimination
Antibodies promote antigen elimination through several mechanisms: neutralization, binding to surface proteins on a virus or bacterium and blocking its ability to infect a host, agglutination, using both binding sites of an antibody to join invading cells together into a clump, Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. Challenge your class to explain the adaptive advantages of antibodies’ Y-shaped structure. Why aren’t antibodies just made up of a single heavy and a single light chain? (Biologists have theorized that the Y shape permits the bonding together of two antigens or antigen-presenting surfaces, allowing a chain reaction or form of clumping.) 2. Figure 24.9 depicts four effector mechanisms and their consequences. This figure organizes the information and relates the processes to each other, making comparisons easier. Such figures are especially helpful for students. Highlighting such figures in your lecture helps students follow up after class discussions by identifying the most relevant sections of their textbook assignments. © 2012 Pearson Education, Inc. 55

24.9 Antibodies mark antigens for elimination
precipitation, similar to agglutination, except that the antibody molecules link dissolved antigen molecules together, and activation of the complement system by antigen-antibody complexes. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. Challenge your class to explain the adaptive advantages of antibodies’ Y-shaped structure. Why aren’t antibodies just made up of a single heavy and a single light chain? (Biologists have theorized that the Y shape permits the bonding together of two antigens or antigen-presenting surfaces, allowing a chain reaction or form of clumping.) 2. Figure 24.9 depicts four effector mechanisms and their consequences. This figure organizes the information and relates the processes to each other, making comparisons easier. Such figures are especially helpful for students. Highlighting such figures in your lecture helps students follow up after class discussions by identifying the most relevant sections of their textbook assignments. © 2012 Pearson Education, Inc. 56

Animation: Antibodies
Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. Challenge your class to explain the adaptive advantages of antibodies’ Y-shaped structure. Why aren’t antibodies just made up of a single heavy and a single light chain? (Biologists have theorized that the Y shape permits the bonding together of two antigens or antigen-presenting surfaces, allowing a chain reaction or form of clumping.) 2. Figure 24.9 depicts four effector mechanisms and their consequences. This figure organizes the information and relates the processes to each other, making comparisons easier. Such figures are especially helpful for students. Highlighting such figures in your lecture helps students follow up after class discussions by identifying the most relevant sections of their textbook assignments. Animation: Antibodies Right click on animation / Click play © 2012 Pearson Education, Inc. 57

Figure 24.9 Effector mechanisms of the humoral immune response
Binding of antibodies to antigens inactivates antigens by Neutralization (blocks viral binding sites; coats bacteria) Agglutination of microbes Precipitation of dissolved antigens Activation of the complement system Complement molecule Bacteria Virus Antigen molecules Bacterium Foreign cell Hole Enhances Leads to Figure 24.9 Effector mechanisms of the humoral immune response Phagocytosis Cell lysis Macrophage 58

Neutralization (blocks viral binding sites; coats bacteria)
Figure 24.9_1 Neutralization (blocks viral binding sites; coats bacteria) Agglutination of microbes Precipitation of dissolved antigens Bacteria Virus Antigen molecules Bacterium Enhances Figure 24.9_1 Effector mechanisms of the humoral immune response (part 1) Phagocytosis Macrophage 59

Activation of the complement system
Figure 24.9_2 Activation of the complement system Complement molecule Foreign cell Hole Leads to Cell lysis Figure 24.9_2 Effector mechanisms of the humoral immune response (part 2) 60

24.10 CONNECTION: Monoclonal antibodies are powerful tools in the lab and clinic
Monoclonal antibodies (mAb) are identical antibodies produced by cells that are all descendants of a single, hybrid cell. To make the hybrid cell with desirable properties, two cells are fused. A cancerous tumor cell, able to multiply indefinitely, is fused to a normal antibody-producing B cell, which is producing the desired antibody. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Once produced, monoclonal antibodies have the ability to specifically identify one particular antigen and bind to it. Challenge your class to think of analogies to this reaction. As you and your class evaluate the analogies, help your class check the analogy against a proper understanding of monoclonal antibody properties (an important point in this chapter). (One possible analogy might be the use of a Phillips screwdriver to turn only Phillips-shaped screw heads.) © 2012 Pearson Education, Inc. 61

Early pregnancy (hCG in the blood and urine)
Figure 24.10 Early pregnancy (hCG in the blood and urine) Urine is applied to the strip hCG hCG/mAb complex Control mAb hCG Figure Monoclonal antibodies used in a home pregnancy test 62

24.10 CONNECTION: Monoclonal antibodies are powerful tools in the lab and clinic
Monoclonal antibodies are useful in research, diagnosis (such as home pregnancy tests), and treatment of certain cancers. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Once produced, monoclonal antibodies have the ability to specifically identify one particular antigen and bind to it. Challenge your class to think of analogies to this reaction. As you and your class evaluate the analogies, help your class check the analogy against a proper understanding of monoclonal antibody properties (an important point in this chapter). (One possible analogy might be the use of a Phillips screwdriver to turn only Phillips-shaped screw heads.) © 2012 Pearson Education, Inc. 63

24.11 Helper T cells stimulate the humoral and cell-mediated immune responses
In the cell-mediated immune response, an antigen-presenting cell displays a foreign antigen (a nonself molecule) and one of the body’s own self proteins to a helper T cell. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The authors note that the recognition by a helper T cell of a self protein and a foreign antigen in combination is like the two-key system used by banks to access safe-deposit boxes. 2. Your students might find the descriptions in Modules and to be particularly confusing, as the interactions of many cell types are described. Figures and help to simplify the details of these interactions. © 2012 Pearson Education, Inc. 64

24.11 Helper T cells stimulate the humoral and cell-mediated immune responses
The helper T cell’s receptors recognize the self–nonself complexes and the interaction activates the helper T cells. The helper T cell can then activate cytotoxic T cells, which attack body cells that are infected with pathogens, and B cells. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The authors note that the recognition by a helper T cell of a self protein and a foreign antigen in combination is like the two-key system used by banks to access safe-deposit boxes. 2. Your students might find the descriptions in Modules and to be particularly confusing, as the interactions of many cell types are described. Figures and help to simplify the details of these interactions. © 2012 Pearson Education, Inc. 65

Animation: Helper T Cells
Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The authors note that the recognition by a helper T cell of a self protein and a foreign antigen in combination is like the two-key system used by banks to access safe-deposit boxes. 2. Your students might find the descriptions in Modules and to be particularly confusing, as the interactions of many cell types are described. Figures and help to simplify the details of these interactions. Animation: Helper T Cells Right click on animation / Click play © 2012 Pearson Education, Inc. 66

Video: T Cell Receptors
Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The authors note that the recognition by a helper T cell of a self protein and a foreign antigen in combination is like the two-key system used by banks to access safe-deposit boxes. 2. Your students might find the descriptions in Modules and to be particularly confusing, as the interactions of many cell types are described. Figures and help to simplify the details of these interactions. Video: T Cell Receptors Use window controls to play © 2012 Pearson Education, Inc. 67

Figure 24.11 Humoral immune response (secretion of antibodies by plasma cells) Phagocytic cell (yellow) engulfing a foreign cell Self-nonself complex B cell Interleukin-2 stimulates cell division T cell receptor Microbe Macrophage 3 5 6 Interleukin-2 activates B cells and other T cells 1 2 Helper T cell 4 7 Figure The activation of a helper T cell and its roles in immunity Self protein Cell-mediated immune response (attack on infected cells) Binding site for the self protein Antigen-presenting cell Cytotoxic T cell Antigen from the microbe (nonself molecule) Interleukin-1 stimulates the helper T cell Binding site for the antigen 68

Antigen-presenting cell Antigen from the microbe (nonself molecule)
Figure 24.11_1 Self-nonself complex Macrophage Microbe 3 1 2 Figure 24.11_1 The activation of a helper T cell and its roles in immunity (part 1) Self protein Antigen-presenting cell Antigen from the microbe (nonself molecule) 69

Interleukin-2 stimulates cell division T cell receptor
Figure 24.11_2 Self-nonself complex B cell Interleukin-2 stimulates cell division T cell receptor 5 6 3 Interleukin-2 activates B cells and other T cells 2 Helper T cell 4 7 Figure 24.11_2 The activation of a helper T cell and its roles in immunity (part 2) Binding site for the self protein Antigen- presenting cell Cytotoxic T cell Interleukin-1 stimulates the helper T cell Binding site for the antigen 70

Phagocytic cell (yellow) engulfing a foreign cell
Figure 24.11_3 Figure 24.11_3 The activation of a helper T cell and its roles in immunity (micrograph) Phagocytic cell (yellow) engulfing a foreign cell 71

24.12 Cytotoxic T cells destroy infected body cells
Cytotoxic T cells are the only T cells that kill infected cells, bind to infected body cells, and destroy them. Cytotoxic T cells also play a role in protecting the body against the spread of some cancers. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. Your students might find the descriptions in Modules and to be particularly confusing, as the interactions of many cell types are described. Figures and help to simplify the details of these interactions. 2. The destruction of an infected cell by a cytotoxic T cell provides an obvious opportunity for a fight analogy. The two cells become interlocked “in battle,” the infected cell develops “puncture wounds,” and a fatal poison is absorbed into these “wounds.” © 2012 Pearson Education, Inc. 72

Animation: Cytotoxic T Cells
Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. Your students might find the descriptions in Modules and to be particularly confusing, as the interactions of many cell types are described. Figures and help to simplify the details of these interactions. 2. The destruction of an infected cell by a cytotoxic T cell provides an obvious opportunity for a fight analogy. The two cells become interlocked “in battle,” the infected cell develops “puncture wounds,” and a fatal poison is absorbed into these “wounds.” Animation: Cytotoxic T Cells Right click on animation / Click play © 2012 Pearson Education, Inc. 73

A cytotoxic T cell binds to an infected cell.
Figure 24.12_s1 1 A cytotoxic T cell binds to an infected cell. Self-nonself complex Foreign antigen Infected cell Cytotoxic T cell Perforin molecule Figure 24.12_s1 How a cytotoxic T cell kills an infected cell (step 1) 74

Figure 24.12_s2 1 A cytotoxic T cell binds to an infected cell. 2 Perforin makes holes in the infected cell’s membrane, and an enzyme that promotes apoptosis enters. Self-nonself complex A hole forming Foreign antigen Infected cell Enzymes that promote apoptosis Cytotoxic T cell Perforin molecule Figure 24.12_s2 How a cytotoxic T cell kills an infected cell (step 2) 75

Figure 24.12_s3 1 A cytotoxic T cell binds to an infected cell. 2 Perforin makes holes in the infected cell’s membrane, and an enzyme that promotes apoptosis enters. 3 The infected cell is destroyed. Self-nonself complex A hole forming Foreign antigen Infected cell Enzymes that promote apoptosis Cytotoxic T cell Perforin molecule Figure 24.12_s3 How a cytotoxic T cell kills an infected cell (step 3) 76

24.13 CONNECTION: HIV destroys helper T cells, compromising the body’s defenses
AIDS (acquired immunodeficiency syndrome), results from infection by HIV, the human immunodeficiency virus. Since 1981 AIDS has killed more than 27 million people, and more than 33 million people live today with HIV. In 2008, 2.7 million people were newly infected with HIV, and over 2 million died, including 300,000 children under age 15. Most AIDS infections and deaths occur in nonindustrialized nations of southern Asia and sub-Saharan Africa. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The Centers for Disease Control and Prevention has extensive information about AIDS and other public health threats on its website at 2. Students often do not understand how disproportionately distributed cases of HIV and AIDS now are in our world. Consider assigning students to identify the regions of the world most affected by HIV/AIDS by performing Internet research. The web site is a good starting point. 3. Despite efforts to educate the general public, many misconceptions about AIDS persist. A list of 18 common misconceptions can be found at the website © 2012 Pearson Education, Inc. 77

The AIDS virus usually attacks helper T cells, impairing the cell-mediated immune response and humoral immune response, and opening the way for opportunistic infections. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The Centers for Disease Control and Prevention has extensive information about AIDS and other public health threats on its website at 2. Students often do not understand how disproportionately distributed cases of HIV and AIDS now are in our world. Consider assigning students to identify the regions of the world most affected by HIV/AIDS by performing Internet research. The web site is a good starting point. 3. Despite efforts to educate the general public, many misconceptions about AIDS persist. A list of 18 common misconceptions can be found at the website © 2012 Pearson Education, Inc. 78

AIDS patients typically die from opportunistic infections and cancers that would normally be resisted by a person with a healthy immune system. Until there is a vaccine or a cure, the best way to stop AIDS is to educate people about how the virus is transmitted. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The Centers for Disease Control and Prevention has extensive information about AIDS and other public health threats on its website at 2. Students often do not understand how disproportionately distributed cases of HIV and AIDS now are in our world. Consider assigning students to identify the regions of the world most affected by HIV/AIDS by performing Internet research. The web site is a good starting point. 3. Despite efforts to educate the general public, many misconceptions about AIDS persist. A list of 18 common misconceptions can be found at the website © 2012 Pearson Education, Inc. 79

Animation: HIV Reproductive Cycle
Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The Centers for Disease Control and Prevention has extensive information about AIDS and other public health threats on its website at 2. Students often do not understand how disproportionately distributed cases of HIV and AIDS now are in our world. Consider assigning students to identify the regions of the world most affected by HIV/AIDS by performing Internet research. The web site is a good starting point. 3. Despite efforts to educate the general public, many misconceptions about AIDS persist. A list of 18 common misconceptions can be found at the website Animation: HIV Reproductive Cycle Right click on animation / Click play © 2012 Pearson Education, Inc. 80

Figure 24.13 Figure A human helper T cell (red) under attack by HIV (blue dots) 81

24.14 EVOLUTION CONNECTION: The rapid evolution of HIV complicates AIDS treatment
HIV mutates very quickly. New strains are resistant to AIDS drugs. Drug-resistant strains now infect new patients. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips 1. The Centers for Disease Control and Prevention has extensive information about AIDS and other public health threats on its website at 2. Students often do not understand how disproportionately distributed cases of HIV and AIDS now are in our world. Consider assigning students to identify the regions of the world most affected by HIV/AIDS by performing Internet research. The web site is a good starting point. 3. Despite efforts to educate the general public, many misconceptions about AIDS persist. A list of 18 common misconceptions can be found at the website © 2012 Pearson Education, Inc. 82

Figure 24.14 Figure A “cocktail” of three separate drugs, the current treatment for people living with HIV 83

24.15 The immune system depends on our molecular fingerprints
The immune system normally reacts only against nonself substances and not against self. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Students may enter your course knowing that the best types of tissue transplants are from a closely matched donor. However, what does it mean to have a tissue “match”? Few students can explain the specific reasons behind the need for tissue matching, or how such matching is done. Challenge your students to explain why we try to ensure a match between the tissues of a donor and a recipient. By posing such general questions, instructors can raise interest in the specific details of the answers. © 2012 Pearson Education, Inc. 84

24.15 The immune system depends on our molecular fingerprints
Transplanted organs may be rejected because the transplanted cells lack the unique “fingerprint” of the patient’s self proteins, called major histocompatibility complex (MHC) molecules. Donors are used that most closely match the patient’s tissues. Transplants between identical twins do not typically have this problem. Student Misconceptions and Concerns 1. For students with limited science backgrounds, this section of the chapter can be particularly difficult; for some, it is the most challenging part of the textbook. Students must have a solid knowledge of the properties of different cells and their interactions, and understand that repeated exposure to antigens generates new interactions. The challenge is similar to explaining a new sport to someone unfamiliar to the game. (Imagine explaining the rules and strategies of football or poker to someone who had never heard of them.) Instructors might consider slowing their pace and using learning aids such as reference lists of cell types and their functions, or diagrams that remind students of these cellular interactions. 2. Having students read relevant material before it is addressed in lecture is one of the best ways to improve student comprehension. Before lecturing on a topic, identify specific textbook modules that should be read before you address them in class. Reading before lecture can lay a foundation that makes the lecture much more meaningful. However, it helps in other ways, too. As students listen in lecture, they know if definitions in lecture are included in the book, and students are already aware of which figures outline certain processes. Teaching Tips Students may enter your course knowing that the best types of tissue transplants are from a closely matched donor. However, what does it mean to have a tissue “match”? Few students can explain the specific reasons behind the need for tissue matching, or how such matching is done. Challenge your students to explain why we try to ensure a match between the tissues of a donor and a recipient. By posing such general questions, instructors can raise interest in the specific details of the answers. © 2012 Pearson Education, Inc. 85

24.16 CONNECTION: Malfunction or failure of the immune system causes disease
Autoimmune diseases occur when the immune system turns against the body’s own molecules. Examples of autoimmune diseases include lupus, rheumatoid arthritis, insulin-dependent diabetes mellitus, and multiple sclerosis. Student Misconceptions and Concerns 1. Student interest in diseases and allergies can provide motivation for learning in this final module. However, researching a medical subject without the necessary background to fully understand it often leads to confusion. Consider probing for misunderstandings about autoimmune diseases and allergies by asking students about their causes and treatments. 2. Students may believe that anything “natural” is somehow good. In addition to the many natural poisons found in animals and plants, our allergic responses to pollen, molds, and other environmental allergens remind us that “natural” is not always healthy. Teaching Tips Although the triggers of autoimmune diseases are not well understood, it does appear that autoimmune diseases are not communicable, and cannot be caught through exposure to others with the disease. Family histories of autoimmune diseases do suggest some degree of heritability, at least of predisposition. Thus, some family members may share degrees of a common autoimmune disease. © 2012 Pearson Education, Inc. 87

Figure 24.16 Figure An X-ray image of hands affected by rheumatoid arthritis 88

24.16 CONNECTION: Malfunction or failure of the immune system causes disease
Immunodeficiency diseases occur when an immune response is defective or absent. The immune system may be weakened by physical stress or emotional stress. Students are more likely to be sick during a week of exams. Student Misconceptions and Concerns 1. Student interest in diseases and allergies can provide motivation for learning in this final module. However, researching a medical subject without the necessary background to fully understand it often leads to confusion. Consider probing for misunderstandings about autoimmune diseases and allergies by asking students about their causes and treatments. 2. Students may believe that anything “natural” is somehow good. In addition to the many natural poisons found in animals and plants, our allergic responses to pollen, molds, and other environmental allergens remind us that “natural” is not always healthy. Teaching Tips Although the triggers of autoimmune diseases are not well understood, it does appear that autoimmune diseases are not communicable, and cannot be caught through exposure to others with the disease. Family histories of autoimmune diseases do suggest some degree of heritability, at least of predisposition. Thus, some family members may share degrees of a common autoimmune disease. © 2012 Pearson Education, Inc. 89

24.17 CONNECTION: Allergies are overreactions to certain environmental antigens
Allergies are hypersensitive (exaggerated) responses to otherwise harmless antigens in our surroundings. Antigens that cause allergies are called allergens. Student Misconceptions and Concerns 1. Student interest in diseases and allergies can provide motivation for learning in this final module. However, researching a medical subject without the necessary background to fully understand it often leads to confusion. Consider probing for misunderstandings about autoimmune diseases and allergies by asking students about their causes and treatments. 2. Students may believe that anything “natural” is somehow good. In addition to the many natural poisons found in animals and plants, our allergic responses to pollen, molds, and other environmental allergens remind us that “natural” is not always healthy. Teaching Tips 1. Allergic contact dermatitis occurs when an allergen triggers an immune response on the skin. One example is the rash that results from exposure to poison ivy. 2. As noted in Module 24.17, antihistamines are drugs that interfere with the action of histamine. They provide temporary relief from the symptoms of allergic reactions. Therefore, a person suffering from a severe reaction to poison ivy might find some relief by taking antihistamines. Unfortunately, antihistamines can also produce drowsiness. © 2012 Pearson Education, Inc. 90

Allergic reactions typically occur very rapidly and in response to tiny amounts of an allergen. Allergic reactions can occur in many parts of the body, including nasal passages, bronchi, and skin. Student Misconceptions and Concerns 1. Student interest in diseases and allergies can provide motivation for learning in this final module. However, researching a medical subject without the necessary background to fully understand it often leads to confusion. Consider probing for misunderstandings about autoimmune diseases and allergies by asking students about their causes and treatments. 2. Students may believe that anything “natural” is somehow good. In addition to the many natural poisons found in animals and plants, our allergic responses to pollen, molds, and other environmental allergens remind us that “natural” is not always healthy. Teaching Tips 1. Allergic contact dermatitis occurs when an allergen triggers an immune response on the skin. One example is the rash that results from exposure to poison ivy. 2. As noted in Module 24.17, antihistamines are drugs that interfere with the action of histamine. They provide temporary relief from the symptoms of allergic reactions. Therefore, a person suffering from a severe reaction to poison ivy might find some relief by taking antihistamines. Unfortunately, antihistamines can also produce drowsiness. © 2012 Pearson Education, Inc. 91

The symptoms of an allergy result from a two-stage reaction. The first stage, called sensitization, occurs when a person is first exposed to an allergen. The second stage begins when the person is exposed to the same allergen later. The allergen binds to mast cells. Mast cells release histamine, causing irritation, itchy skin, and tears. Student Misconceptions and Concerns 1. Student interest in diseases and allergies can provide motivation for learning in this final module. However, researching a medical subject without the necessary background to fully understand it often leads to confusion. Consider probing for misunderstandings about autoimmune diseases and allergies by asking students about their causes and treatments. 2. Students may believe that anything “natural” is somehow good. In addition to the many natural poisons found in animals and plants, our allergic responses to pollen, molds, and other environmental allergens remind us that “natural” is not always healthy. Teaching Tips 1. Allergic contact dermatitis occurs when an allergen triggers an immune response on the skin. One example is the rash that results from exposure to poison ivy. 2. As noted in Module 24.17, antihistamines are drugs that interfere with the action of histamine. They provide temporary relief from the symptoms of allergic reactions. Therefore, a person suffering from a severe reaction to poison ivy might find some relief by taking antihistamines. Unfortunately, antihistamines can also produce drowsiness. © 2012 Pearson Education, Inc. 92

Figure 24.17 The two stages of an allergic reaction
Sensitization: Initial exposure to an allergen Later exposure to the same allergen B cell (plasma cell) Mast cell Antigenic determinant Histamine 1 An allergen (pollen grain) enters the bloodstream. Figure The two stages of an allergic reaction 2 B cells make antibodies. 3 Antibodies attach to a mast cell. 4 The allergen binds to antibodies on a mast cell. 5 Histamine is released, causing allergy symptoms. 93

Sensitization: Initial exposure to an allergen
Figure 24.17_1 Sensitization: Initial exposure to an allergen B cell (plasma cell) Mast cell Figure 24.17_1 The two stages of an allergic reaction (part 1) Antigenic determinant Histamine 1 An allergen (pollen grain) enters the bloodstream. 2 B cells make antibodies. 3 Antibodies attach to a mast cell. 94

Later exposure to the same allergen
Figure 24.17_2 Later exposure to the same allergen Figure 24.17_2 The two stages of an allergic reaction (part 2) 4 The allergen binds to antibodies on a mast cell. 5 Histamine is released, causing allergy symptoms. 95

Antihistamines interfere with histamine’s action, provide temporary relief, but often make people drowsy. Anaphylactic shock is an extreme life-threatening allergic reaction and can be treated with injections of epinephrine. Student Misconceptions and Concerns 1. Student interest in diseases and allergies can provide motivation for learning in this final module. However, researching a medical subject without the necessary background to fully understand it often leads to confusion. Consider probing for misunderstandings about autoimmune diseases and allergies by asking students about their causes and treatments. 2. Students may believe that anything “natural” is somehow good. In addition to the many natural poisons found in animals and plants, our allergic responses to pollen, molds, and other environmental allergens remind us that “natural” is not always healthy. Teaching Tips 1. Allergic contact dermatitis occurs when an allergen triggers an immune response on the skin. One example is the rash that results from exposure to poison ivy. 2. As noted in Module 24.17, antihistamines are drugs that interfere with the action of histamine. They provide temporary relief from the symptoms of allergic reactions. Therefore, a person suffering from a severe reaction to poison ivy might find some relief by taking antihistamines. Unfortunately, antihistamines can also produce drowsiness. © 2012 Pearson Education, Inc. 96

You should now be able to
Describe the functions of neutrophils. Describe the nature of innate defenses in invertebrates and vertebrates. Describe the steps of the inflammatory response and explain how they help to prevent the spread of disease. Describe the specific nature of adaptive immune system responses. Describe the development and functions of B lymphocytes and T lymphocytes. © 2012 Pearson Education, Inc. 97

Define and distinguish between the humoral immune response and the cell-mediated immune response. Describe the nature of antigens. Explain how an antigen and an antibody interact. Describe the process of clonal selection and compare a primary immune response to a secondary immune response. Describe the specific structure of an antibody and relate its shape to its functions. © 2012 Pearson Education, Inc. 98

Describe four effector mechanisms of the humoral immune system. Describe the production and uses of monoclonal antibodies. Describe the specific functions of helper T cells and how they interact with other cells. Explain how cytotoxic T cells destroy infected body cells. Explain how HIV infects cells, multiplies, and causes disease. © 2012 Pearson Education, Inc. 99

Explain why it has been difficult to develop a successful treatment for AIDS. Explain how the immune system identifies the body’s own molecules and how this system complicates organ transplantations. Describe how the malfunction or failure of the immune system can cause disease. Explain why allergies occur and what causes anaphylactic shock. © 2012 Pearson Education, Inc. 100

The humoral immune response:
Figure 24.UN01 The humoral immune response: makes which bind to B cell Antibodies Antigens in body fluid The cell-mediated immune response: Infected body cell Figure 24.UN01 Reviewing the Concepts, 24.5 T cell Self-nonself complex 101

Figure 24.UN02 Connecting the Concepts, question 1
Body’s defenses include (a) (b) is present found in is present found in vertebrates and invertebrates only after exposure at birth vertebrates produced by cells called Lymphocytes include Figure 24.UN02 Connecting the Concepts, question 1 responsible for cell-mediated immune response (c) (d) secrete responsible for include humoral immune response stimulate cytotoxic T cells (e) (f) stimulate 102

vertebrates and invertebrates produced by cells called
Figure 24.UN02_1 Body’s defenses include (a) (b) is present found in is present found in vertebrates and invertebrates only after exposure at birth vertebrates Figure 24.UN02_1 Connecting the Concepts, question 1 (part 1) produced by cells called Lymphocytes 103

cell-mediated immune response humoral immune response
Figure 24.UN02_2 Lymphocytes include responsible for cell-mediated immune response (c) (d) secrete responsible for include stimulate Figure 24.UN02_2 Connecting the Concepts, question 1 (part 2) humoral immune response cytotoxic T cells (e) (f) stimulate 104

Figure 24.17_UN01 Figure 24.17_UN01 An “epi pen” for counteraction of anaphylactic shock 105

Chapter 24 The Immune System.

Similar presentations

Presentation on theme: "Chapter 24 The Immune System."— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Chapter 24 The Immune System.

Similar presentations

Presentation on theme: "Chapter 24 The Immune System."— Presentation transcript:

Similar presentations

About project

Feedback