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After completing chapter 28, you will be able to: List the pathways and organs of the lymphatic system and give their locations; define lymph and tell how it is circulated in the body; define the terms infection, pathogen, and antigen; list and describe the nonspecific body defense mechanisms; explain the signs and causes of inflammation.
CHAPTER 28 The Lymphatic and Immune Systems 28-2 Learning Outcomes (cont.) 28.1 Describe the pathways and organs of the lymphatic system 28.2 Compare the nonspecific and specific body defense mechanisms 28.3 Explain how antibodies fight infection 28-3 Learning Outcomes (cont.) 28.4 Describe the four different types of acquired immunities 28.5 Describe the causes, signs and symptoms, and treatments of major immune disorders 28-4 Introduction • Immune system – Protects against • • • • • • Bacteria Viruses Fungi Toxins Parasites Cancer • Lymphatic system – Works with the immune system – Organs • Thymus • Spleen • Lymph nodes 28-5 The Lymphatic System • Network of connecting vessels • Functions to – Collect lymph from between cells – Collect lipids from digestive organs – Defend the body against pathogens 28-6 Lymphatic Pathways • Lymphatic capillaries – Collect fluid – Deliver lymph to lymphatic vessels • Lymph vessels – lymph to nodes • Lymph nodes – Remove pathogens – Start immune response Lymph System 28-7 Lymphatic Pathways (cont.) • Efferent lymphatic vessels trunks lymphatic • Lymphatic collecting ducts – Thoracic duct – Right lymphatic duct • Empty into blood stream Lymph System 28-9 The Lymphatic System (cont.) Area Drained by right lymphatic duct Right lymphatic duct Lymph nodes Lymphatic trunks Lymphatic vessels Left internal jugular vein Thoracic duct Left subclavian vein Thoracic duct Cisterna chyli 28-10 Tissue Fluid and Lymph • Interstitial fluid – Fluid in spaces between cells – High in nutrients, oxygen, and small proteins – Fluid not picked up by cells lymph • Lymph moves by – Squeezing action of skeletal muscles – Squeezing action of breathing 28-11 Lymph Nodes • Small, glandular structures • Afferent lymphatic vessels ~ lymph to node • Efferent lymphatic vessels ~ lymph from node 28-36 Apply Your Knowledge After you give an immunization to a 2-year-old, her mother asks you why this will work to prevent her from getting a disease What would you tell her? ANSWER: Immunization is an artificially acquired immunity A person develops this immunity by being injected with a pathogen and then making antibodies and memory cells against the pathogen 28-37 Major Immune System Disorders • Cancer – Uncontrolled growth of abnormal cells – Carcinogen – Signs/symptoms vary – Treatment based on staging 28-38 Major Immune System Disorders (cont.) Stage Description Very early cancer Cancer cells are Stage localized in a few cell layers Cancer cells have spread to deeper cell Stage I layers, or some may have spread to surrounding tissues Cancer cells have spread to surrounding Stage II tissues but are considered contained in the primary cancer site 28-39 Major Immune System Disorders (cont.) Stage Description Stage III Cancer cells have spread beyond the primary cancer site to nearby areas Stage IV Cancer cells have spread to other organs of the body Recurrent Cancer cells have reappeared after treatment 28-40 Major Immune System Disorders (cont.) • Allergies – Immune responses to an allergen – IgE antibodies • Bind to allergens • Stimulate mast cells – Allergy shots – Anaphylaxis ~ life threatening allergic response 28-41 Major Immune System Disorders (cont.) • Allergies (cont.) – Signs/symptoms are based on where exposure occurs – Treatment • Antihistamines, decongestants • Epinephrine for anaphylaxis Common Diseases and Disorders of the Immune System • Autoimmune disease – Body attacks its own antigens – Examples • • • • • • Scleroderma Rheumatoid arthritis Multiple sclerosis Glomerulonephritis Crohn’s disease Diabetes mellitus, type I 28-42 Common Diseases and Disorders of the Immune System (cont.) Disorder Acquired immunodeficiency syndrome (AIDS) Description Development of severe signs and symptoms caused by HIV as it destroys lymphocytes (T cells); leaves immune system weakened and susceptible to other diseases Chronic fatigue syndrome (CFS) Condition of severe tiredness not relieved by rest and not related to other illnesses 28-43 28-44 Common Immune System Disorders (cont.) Disorder Lymphedema Description Blockage of lymphatic vessels resulting in tissue swelling Mononucleosis “Mono”; highly contagious viral infection spread through saliva of infected person Systemic lupus Autoimmune disorder; produces erythematous antibodies that target own cells (SLE) and tissues; affects women more often than men 28-45 Apply Your Knowledge Matching: ANSWER: G Immune response to a substance _ A CFS E Blockage of lymphatic vessels _ B SLE F “Kissing disease” _ C Cancer B “Butterfly” rash on face _ disease D Autoimmune E Lymphedema A Severe tiredness _ C Uncontrolled growth of _ abnormal cells F Mononucleosis G Allergy D Body attacks its own antigens _ 28-46 In Summary 28.1 The lymph system is composed of pathways known as lymph vessels In addition to the lymph vessels, the organs of the lymphatic system include lymph nodes, located throughout the body; the thymus, in the mediastinum; and the spleen, located in the LUQ 28.2 Nonspecific body defenses include species resistance, mechanical and chemical barriers, phagocytosis, fever, and inflammation Specific defenses are immunities or defenses against very specific antigens created by B cells, T cells, and natural killer (NK) cells 28-47 In Summary (cont.) 28.3 Antibodies work in the following ways: phagocytosis, antigen clumping, covering (inactivating) toxic portions of antigens, and activating complements Antibodies are also known as immunoglobulins IgA prevents pathogens from entering the body; IgD controls B cell activity; IgE works with IgA in triggering allergic reactions; IgG recognizes bacteria, viruses, and toxins and activates complements; and IgM binds to antigens on food, bacteria, or incompatible blood cells IgM also activates complements 28-48 In Summary (cont.) 28.4 The four types of immune response are naturally acquired active immunity, such as when someone becomes ill and develops immunity; artificially acquired active immunity, as when an injection is given against a pathogen, preventing illness; naturally acquired passive immunity, which occurs when an infant has its mother’s immunity for a short while after birth and through breast milk; and artificially acquired passive immunity, which occurs after injection of antibodies such as with an antivenom 28-49 In Summary (cont.) 28.5 Diseases and disorders of the immune system include HIV infection, AIDS, cancer, and allergies, as well as other autoimmune diseases, in which the body attacks its own antigens The signs, symptoms and treatments are as numerous and varied as the diseases Some of the more common diseases and disorders are discussed in the Common Diseases and Disorders of the Immune System section near the end of this chapter 28-50 End of Chapter 28 Thought is an infection In the case of certain thoughts, it becomes an epidemic ~Wallace Stevens .. .28- 2 Learning Outcomes (cont.) 28. 1 Describe the pathways and organs of the lymphatic system 28. 2 Compare the nonspecific and specific body defense mechanisms 28. 3 Explain how... entire abdominopelvic area, and both legs; and the right lymphatic duct, which drains the right side of the head and neck, right arm, and right side of the chest 28- 17 Defenses Against Disease... cells 28- 16 Apply Your Knowledge What are the lymphatic collecting ducts and what area they drain? ANSWER: The collecting ducts are: Thoracic duct, which drains the left side of the head and neck,