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UNIT 9 The Immune System 11 - 1 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The Function of the Immune System The function of the immune system is to create effective immune responses to continually defend the body against antigens. 11 - 2 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphatic System Function Network of vessels that transport fluids Lymphatic vessels carry away excess fluid from interstitial spaces and return it to blood stream Attacks foreign particles, cancer cells and toxins 11 - 3 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Overview https://study.com/academy/lesson/functio ns-of-the-lymphatic-system.html 11 - 4 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphatic Pathways Lymphatic Capillaries Microscopic tubes Extend into interstitial spaces Parallel to blood capillaries Simple Squamous epithelium Fluid is called lymph (limf) 11 - 5 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphatic Pathways 11 - 6 Lymphatic Vessels Similar to veins, but thinner Have flap like valves to prevent backflow of lymph (like veins) Larger vessels lead to specialized organs called lymph nodes After leaving lymph nodes, vessels merge to form even larger lymph trunks Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 11 - 7 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphatic Pathways Lymphatic Trunks & Collecting Drains Lymphatic trunks, which drain lymph, are named for the region they serve Join one or two collecting ducts Thoracic duct Right lymphatic duct 11 - 8 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphatic Pathways Lymphatic Trunks & Collecting Ducts Thoracic Duct – Longer and larger collecting duct Received lymph from: lower limbs, abdominal region, left upper limb and left side of the thorax, head and neck Empties into left subclavian vein near the junction of the left jugular vein 11 - 9 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 11 - 10 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphatic Pathways Lymphatic Trunks & Collecting Ducts Right Lymphatic Duct Receives lymph from: right side of head and neck, right upper limb, and right thorax Empties into right subclavian vein near junction of right jugular vein After leaving collecting ducts, lymph enters venous system and becomes part of plasma 11 - 11 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphatic Pathway Lymphatic capillary lymphatic vessel lymph node lymphatic vessel lymphatic trunk collecting duct subclavian vein 11 - 12 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Tissue Fluid & Lymph Lymph is tissue fluid that has entered a lymphatic capillary Lymph formation depends on tissue fluid formation 11 - 13 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Tissue Fluid Formation Tissue fluid originates from blood plasma Composed of water & dissolved substances that leave blood capillaries Capillary blood pressure causes filtration of water and other molecules from the plasma 11 - 14 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymph Movement Lymph is under low hydrostatic pressure and may not flow readily without outside help These forces include: Skeletal muscle Smooth muscle Breathing 11 - 15 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymph Movement Skeletal Muscle Contracting skeletal muscle compresses lymphatic vessels and moves lymph in these vessels Vessels have valves lymph can only travel towards collecting duct Smooth Muscle Smooth muscle in walls of lymphatic trunks can contract & compress lymph inside, moving it forward 11 - 16 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymph Movement Breathing Creates relatively low pressure in thoracic cavity during inhalation At the same time, diaphragm increases pressure in abdominal cavity This forces lymph from abdominal vessels to thoracic vessels 11 - 17 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The Organs of the Immune System Bone marrow Thymus Lymph nodes Spleen Tonsils Adenoids Appendix Peyer’s patches: clumps of lymph tissue 11 - 18 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 11 - 19 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymph Nodes Located along lymphatic pathways Contain many lymphocytes and macrophages – fight invading organisms 11 - 20 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymph Nodes Structure Vary in size & shape, but usually less than 2.5cm long, bean shaped Hilum – indented region where blood vessels and nerves join Lymphatic vessels exit from here Capsule of connective tissue enclose nodes Peyer’s Patches – aggregations of nodules scattered throughout ileum region of small intestine 11 - 21 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 11 - 22 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Locations 11 - 23 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Functions of Lymph Nodes Filtering potentially harmful particles from lymph before returning it to blood stream Immune Surveillance – lymphocytes & macrophages 11 - 24 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Thymus Large during infancy/childhood – shrinks during puberty Connective tissues extend inward from surface, subdividing the gland into lobules Abundant lymphocytes Most cells (thymocytes) are inactive, but some mature into Tcells that leave thymus & provide immunity 11 - 25 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Thymus 11 - 26 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Spleen Largest lymphatic organ Resemble lymph node, but the spaces of the spleen contain blood instead of lymph White Pulp – islands throughout spleen. Contains many lymphocytes Red Pulp – RBC, lymphocytes, macrophages Filters blood, like lymph nodes filter lymph 11 - 27 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Spleen 11 - 28 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Body Defenses Against Infection Innate (nonspecific) defense General, protect against many pathogens Adaptive (specific) defense Precise, targets certain pathogens https://study.com/academy/lesson/what-isthe-immune-system-our-bodys-defenseagainst-pathogens.html 11 - 29 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Innate Defenses Species Resistance – each species has a specific set of diseases that is unique to it Mechanical Barriers – 1st line of defense 11 - 30 Ex: Pathogens that cause measles and mumps affect humans, but not other species Skin & mucus membranes (hair, mucus, sweat) https://study.com/academy/lesson/theinnate-immune-system-definition-andcomponents.html Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Innate Defenses Chemical Barriers – Enzymes in body fluid Ex: Gastric juice & tears contain enzymes and antibacterial agents that kill many pathogens Lymphocytes and fibroblasts produce interferons in response to viruses or tumor cells Once released from virus-infected cell, interferon binds to receptors on uninfected cells, causing them to produce proteins that block replication of a variety of viruses 11 - 31 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Innate Defenses Fever – higher body temperature causes liver and spleen to hold on to iron. Bacteria & fungi need iron to produce in high temperatures Phagocytosis – neutrophils & monocytes are blood’s most active phagocytes Removes foreign particles from lymph as it moves from interstitial spaces to blood stream Innate Defenses Inflammation – tissue response to injury or infection, causing localized redness, heat, and pain Results in walling off of the site so infection cannot spread Brings more blood to area with phagocytes to remove microorganisms Heat speeds up phagocytes Infected cells stimulate WBC to area. In bacterial infections, this may create pus 11 - 33 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Adaptive Defenses Antigens Things the immune system sees as non-self, such as bacteria, viruses, fungi, and parasites The body responds by destroying them or rendering them ineffective. 11 - 34 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Adaptive Defenses Lymphocyte Origins Before birth, red bone marrow releases undifferentiated lymphocytes into circulation About half reach the thymus where they develop into T Cells » Other T Cells reside in lymphatic organs, lymph nodes, thoracic duct and spleen Other non-T lymphocytes remain in red bone marrow until they differentiate into B cells 11 - 35 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Adaptive Defenses Lymphocyte functions T cells attach to foreign, antigen bearing cells and interact directly (cell to cell contact) Cellular immune response B cells, when stimulated by antigen, grow and divide into plasma cells that produce antibodies or immunoglobulins Humoral immune response 11 - 36 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. T Cells Act directly on target cells and provide cell-mediated immunity 11 - 37 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The 4 Types of T Cells 1. Helper T cells 2. Suppressor T cells 11 - 38 Produce proteins that help other lymphocytes and phagocytes perform their functions Also help B lymphocytes make antibodies Stop or turn off T cell actions when the “battle” is under control (continued) Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The 4 Types of T Cells 3. Memory T cells 4. Have a memory from previous experiences with specific antigens and are prepared to act immediately upon recontact Killer T cells Can directly kill infected or malignant cells and those cells carrying a target antigen Can attach to the target and insert toxic chemicals that make holes in the membrane and destroy the cell before it can reproduce 11 - 39 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. How NK Cell Action Differs from Phagocytic Action Natural killer (NK) cells can kill cancer cells and cells infected with viruses without using antibodies or having prior exposure to the antigen. This is done by injecting a toxin into the membrane to destroy the cell, instead of eating it as phagocytes would. 11 - 40 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Major Histocompatibility Complex (MHC) Molecules that function as biochemical “fingerprints” This serves as the “ID” for cells so they are marked and recognized as self. 11 - 41 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The Purpose of MHC MHC markers enable the immune system to achieve its primary function of communication. The body can recognize cells as self and non-self. This promotes homeostasis through the destruction of damaged or dead cells. 11 - 42 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The Role of the B Cell B lymphocytes produce antibodies in a process called humoral immunity B cells have 2 stages of development: 1. 2. Cells insert molecules of one specific antibody into the cell membrane. The antibody contacts antigens and they change into an antigen-antibody complex. 11 - 43 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The Body’s 3 Main Lines of Defense 1. First line of defense: barriers 11 - 44 Anatomic barrier: the skin, mucous membranes, and intestinal tract Biochemical barrier: sebaceous glands, tears, and sweat Mechanical: coughing, urination, and skin cells slough off (continued) Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The Body’s 3 Main Lines of Defense 2. Second line of defense: the inflammation process 11 - 45 Begins within seconds of an injury or invasion Area becomes red, swollen, and warm to the touch (continued) Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The Body’s 3 Main Lines of Defense 3. Third line of defense: antibody defense This is our immunity. Results from a dual-system response and involves the actions of specific cells and other immune system components to attack the antigen. 11 - 46 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 3 Basic Services of the Immune System 1. 2. 3. Identifies self and destroys non-self substances Maintains a normal internal environment (homeostasis) Conducts continual surveillance 11 - 47 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Allergens The result of an inappropriate response to a harmless substance such as grass, cat hair, etc. This results in the condition known as an allergy. 11 - 48 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Allergic Reactions Immune attack against a non-harmful substance Similar to immune response – synthesize lymphocytes, antibodies may bind antigens, but allergic reactions may damage tissues Allergy testing https://www.youtube.com/watch?v=atOI5c_u NIs 11 - 49 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Tissue Rejection Reaction Recipient’s immune system may recognize the donor’s cell surfaces as foreign Resembles cellular immune response Immunosuppressive drugs are used to prevent this Suppresses formation of antibodies and T cells 11 - 50 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Autoimmunity Attack against self Immune system fails to distinguish self from non-self 11 - 51 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Vaccines https://study.com/academy/lesson/immu nization-and-vaccination.html https://study.com/academy/lesson/antibio tics-and-vaccines.html 11 - 52 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Diseases and Disorders 11 - 53 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. https://study.com/academy/lesson/immunedeficiency-diseases-definitions-types.html 11 - 54 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. https://study.com/academy/lesson/autoi mmune-diseases-andhypersensitivity.html 11 - 55 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. AIDS Acquired immunodeficiency syndrome The most advanced stage of the human immunodeficiency virus (HIV) This syndrome renders the body’s immune system ineffective. 11 - 56 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. How AIDS Destroys the Immune System The virus invades the T cells and macrophages. With the helper T cells disabled, the macrophages do no act, the B cell antibodies are diverted, and there is no NK cell formation. 11 - 57 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 5 Ways to Acquire the AIDS Virus 1. 2. 3. 4. 5. Unprotected sex with an infected partner Sharing drug needles or syringes HIV-positive mother passes it on to her child Blood transfusions Accidental needlesticks and contact with infected blood 11 - 58 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 4 High-Risk Behaviors to Avoid 1. 2. 3. 4. High-risk sexual activities Using intravenous drugs and sharing needles Having multiple sex partners Untreated sexually transmitted diseases 11 - 59 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The 3 Most Common Opportunistic Diseases Pneumocystis carinii pneumonia Kaposi’s sarcoma Lung infection with fever, cough, and dyspnea Form of cancer that appears as purplish skin blotches Candidiasis Yeast infection that can attack the mouth, esophagus, and vagina 11 - 60 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Cancer A group of diseases characterized by the growth of abnormal cells These cells accumulate and form tumors that may compress, invade, or destroy normal tissue. The spread of a tumor to a new site is called metastasis. 11 - 61 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. The Classifications of Cancer Cancer is classified according to its cellular origin Carcinomas arise from epithelial tissue. Sarcomas arise from connective tissue. Leukemias arise from blood and bloodforming organs. 11 - 62 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Describing Grading and Staging of Cancer Grading describes the degree of cell differentiation from grade I to grade IV Grade I Cells are well differentiated. Grade IV Cells are undifferentiated. 11 - 63 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Staging Staging identifies the extent of the spread of the disease T: size of the primary tumor N: presence or absence of regional metastasis M: presence or absence of distant metastasis 11 - 64 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 4 Types or Categories of Carcinogens 1. 2. 3. 4. Chemical: arsenic, tobacco, benzene, etc. Viral: Epstein-Barr, hepatitis B, leukemia, etc. Physical: asbestos, radiation, etc. Familial: melanoma, leukemia, etc. 11 - 65 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Chronic Fatigue Syndrome A debilitating disorder that causes overwhelming fatigue that lasts at least 6 months and does not go away with rest 11 - 66 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphedema Swelling of body tissues caused by an accumulation of lymphatic fluid 11 - 67 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lymphedema Wrapping https://www.youtube.com/watch?v=jC6LzOlI1w 11 - 68 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Lupus Chronic disease that causes changes in the immune system This disorder causes inflammation. Lupus can involve only a few body organs or can cause serious, lifethreatening problems. 11 - 69 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. How Lupus Affects the Immune System and Major Body Organs Usually protective antibodies are produced in large quantities, but they react against the person’s own normal tissues 11 - 70 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Rheumatoid Arthritis A chronic systemic inflammatory autoimmune disease that affects the joints and surrounding muscles, tendons, ligaments, and blood vessels 11 - 71 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Diagnostic Tests and Treatments 11 - 72 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 3 Categories of Diagnostic Testing 1. 2. 3. Biopsies: visual examination of cells removed by needle aspiration, excision, or bone marrow aspiration Lab tests: Blood, semen, and urine are evaluated for abnormal cancer cells and tumor markers. Tumor imaging: x-rays, CT scans, and MRIs 11 - 73 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Major Cancer Treatment Methods Surgery Chemotherapy Radiation: external beam therapy Radiation: brachytherapy Radiation: biosurgery Biological response modifiers Gene therapy Complementary therapy Alternative therapy 11 - 74 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Immunization and Vaccinations The deliberate introduction of an antigen into the body, which causes a minor reaction in the patient After injection, the body produces an antigen-antibody complex and eventually memory cells against the disease are produced. 11 - 75 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. Boy in a Bubble https://www.youtube.com/watch?v=4CFP dUAj41Y 11 - 76 Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.