© 2009 the mcgraw-hill companies, inc. all rights reserved the lymphatic and immune systems...
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© 2009 The McGraw-Hill Companies, Inc. All rights reserved
The Lymphatic and Immune The Lymphatic and Immune SystemsSystems
PowerPoint® presentation to accompany:
Medical AssistingThird Edition
Booth, Whicker, Wyman, Pugh, Thompson
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© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Learning Outcomes32.1 List the pathways and organs of the lymphatic system
and give their locations.
31.2 Define lymph and tell how it is circulated in the body.
31.3 Define the terms infection, pathogen, and antigen.
31.4 List and describe the nonspecific body defense mechanisms.
31. 5 Explain the signs and causes of inflammation.
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Learning Outcomes (cont.)
32.6 Explain what is meant by body defenses.
32.7 Define B cells and T cells and describe their locations and functions.
32.8 Explain the importance of MHC proteins.
32.9 List the different types of T cells and describe their functions.
32.10 Explain how antibodies fight infection.
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Learning Outcomes (cont.)
32.11 List the different types of antibodies and tell how they differ.
32.12 Define complement proteins and give their function.
32.13 Explain the difference between the primary immune response and secondary immune response.
32.14 Explain the four different types of acquired immunities.
32.15 Describe the function of a vaccine.
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Learning Outcomes (cont.)
32.16 Define the terms cancer and carcinogen.
32.17 Describe how cancers are diagnosed and treated.
32. 18 Explain how cancers are classified.
32.19 Describe how allergies develop.
32.20 Describe the causes, signs and symptoms, and treatments of other common immune disorders.
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Introduction
Immune system Protects the body
against Bacteria Viruses Fungi Toxins Parasites Cancer
Lymphatic system Works with immune
system to remove disease-causing agents
Organs Thymus Spleen Lymph nodes
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The Lymphatic System
Network of connecting vessels Collects fluid (lymph) between cells and returns
it to bloodstream
Picks up lipids from digestive organs and transports them to blood stream
Functions to defend the body against pathogens
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Lymphatic System: Pathways
Lymphatic capillaries Extend into interstitial spaces Permeable, thin walls pick up fluid, now lymph Delivers lymph to lymphatic vessels
Lymphatic vessels Deliver lymph to lymph nodes
Cells in nodes can remove pathogens from lymph and start an immune response
Leaves nodes through efferent lymphatic vesselsLymph System
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Lymphatic System: Pathways (cont.)
Lymphatic trunks Receive lymph from efferent lymphatic vessels Deliver it to
Lymphatic collecting ducts Thoracic duct
Left side of head and neck, left arm, left side of thorax, entire abdominopelvic area, and both legs
Right lymphatic duct Right side of head and neck, right arm, and right side of chestLymph
System
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Lymphatic System: Tissue Fluid and Lymph
Interstitial fluid Fluid in spaces between cells that has leaked
from blood capillaries and has not been picked up by body cells
High in nutrients, oxygen, and small proteins Becomes lymph
Pushed through lymphatic vessels by squeezing action of neighboring skeletal muscles and breathing movement
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Lymphatic System: Nodes
Small, glandular structures
Located along paths of larger lymphatic vessels Afferent lymphatic vessels
– Lymph to node Efferent lymphatic vessels
– Lymph from node
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More lymph enters than can leave at one time
Cells in nodes Macrophages – digest unwanted
pathogens Lymphocytes – start an immune
response against pathogen
Nodes can generate some lymphocytes
Lymphatic System: Nodes (cont.)
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Lymphatic System: The Thymus and Spleen
Thymus Soft, bi-lobed organ
Located just above the heart in the mediastinum
Large in children, shrinks as we age
Functions Same as lymph nodes
Also produces lymphocytes
Produces thymosin – stimulates production of lymphocytes
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Spleen Largest lymphatic organ
Located in the upper left quadrant of abdominal cavity
Functions Filters blood similarly to lymph nodes
Removes worn-out red cells
If removed (splenectomy), liver takes over most of its
function
Lymphatic System: The Thymus and Spleen (cont.)
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Apply Your Knowledge
What are the lymphatic collecting ducts and what area do they drain?
ANSWER: The collecting ducts are: Thoracic duct, which drains the left side of the head and neck, left arm, left side of thorax, 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.
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Defenses Against Disease Infection
The presence of a pathogen in or on the body
Pathogen A disease-causing agent
Innate immunity Nonspecific defenses to
protect against pathogens
Nonspecific defenses Species resistance
Mechanical barriers
Chemical barriers
Phagocytosis
Fever
Inflammation
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Defenses Against Disease: Specific Defenses
Immunities Protect against very
specific pathogens Antigens
Foreign substances in the body
Haptens Foreign substances too
small to start an immune response by themselves
Other substances Proteins – antibodies and
complements WBCs – lymphocytes and
macrophages Lymph system
Cytokines – assist in immune response regulation
Monokines – increase B cell production and stimulate WBC production
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Defenses Against Disease (cont.)
Two major types of lymphocytes
B Cells and T Cells
Recognize antigens in the body
T Cells Cell-mediated response Bind to antigens on cells
and attack them directly Secrete lymphokines that increase T cell production and directly kill cells with antigens
T Cells Cell-mediated response Bind to antigens on cells
and attack them directly Secrete lymphokines that increase T cell production and directly kill cells with antigens
B cells Respond to antigens by becoming plasma cells Plasma cells make antibodies Memory B cells produce stronger response with next exposure to antigen
B cells Respond to antigens by becoming plasma cells Plasma cells make antibodies Memory B cells produce stronger response with next exposure to antigen
Response
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Defenses Against Disease (cont.)
T cell activation Begins when macrophage ingests and digests
pathogen with antigen on it Antigens are placed on cell membrane of
macrophage T cell recognizes and binds to antigen and the
major histocompatibility complex (MHC) on the surface of the macrophage
Now can divide to form other types of T cells
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Defenses Against Disease (cont.)
Types Cytotoxic T cells
Protect body against viruses and cancer cells Helper T cells
Increase antibody formation, memory cell formation, B cell formation, and phagocytosis
Memory T cells Remember the pathogen that activated original T cell Later exposures trigger an immune response more
effective than initial response
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Defenses Against Disease (cont.)
Natural killer (NK) cells
Type of lymphocyte
Primarily target cancer cells
Kill on contact
Do not recognize a specific antigen
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Apply Your Knowledge
Identify whether each item refers to T cells, B cells, or NK cells:
___ Primarily target cancer cells
___ Respond to antigens by becoming plasma cells
___ Must be activated to respond to an antigen
___ Bind to antigens on cells and attack them directly
___ Kill on contact
___ Need macrophages and MHC for activation
___ Make antibodies against specific antigen
B
NK
T
T
T
B
NK
ANSWER:
Right on Target!
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Antibodies
Also called immunoglobulins IgA
Prevents pathogens from entering body IgD
Found on B cell membranes Thought to control B cell activity
IgE Found with IgA Involved in triggering allergic reactions
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Antibodies (cont.)
IgG Recognizes bacteria, viruses, and toxins Activates complements
IgM Large and binds to antigens on food, bacteria, or
incompatible blood cells Activates compliments
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Antibodies (cont.)
Actions that occur when antibodies bind to antigens Allow phagocytes to recognize and destroy antigens
Cause antigens to clump together, causing them to be destroyed by macrophages
Cover the toxic portions of antigens, making them harmless
Activate complement Group of proteins in serum that attack pathogens by forming holes
in them
Attract macrophages to pathogens and can stimulate inflammation
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Apply Your Knowledge
What are the possible actions that occur when antibodies bind to antigens?
ANSWER: Possible actions include: They allow phagocytes to recognize and destroy antigens. They make antigens clump together, causing them to be destroyed by macrophages. They cover the toxic portions of antigens to make them harmless. They activate complements.
Very Good!
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Immune Responses and Acquired Immunity
Primary immune response occurs with first exposure to antigen Slow process Memory cells are formed
Secondary immune response with next exposure to same antigen Quick and carried out by memory cells Usually prevents person from developing disease from
the antigen
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Immune Responses and Acquired Immunity (cont.)
Naturally acquired active immunity Natural exposure to antigen – having an illness Makes antibodies and memory cells Long-lasting
Artificially acquired active immunity Injected with pathogen – immunizations Makes antibodies and memory cells Long-lasting
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Immune Responses and Acquired Immunity (cont.)
Naturally acquired passive immunity Acquired from mother
Breast milk Placenta
Short-lived
Artificially acquired passive immunity Injected with antibodies (such as antivenom) Short-lived
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Apply Your Knowledge
ANSWER: Immunization is an artificially acquired immunity because a person develops this immunity by being injected with a pathogen and then making antibodies and memory cells against the pathogen.
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.
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Major Immune System Disorders Cancer
Uncontrolled growth of abnormal cells form malignant tumors
200 known types Treatment based on stage
0 – very early; cancer cells localizedI – spread to deeper layers or some in surrounding tissuesII – spread to surrounding tissues but contained in primary siteIII – spread beyond primary site into nearby areasIV – spread to other organsRecurrent – reappeared after treatment
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Major Immune System Disorders (cont.)
Allergies Immune response to an allergen
Can be excessive IgE antibodies bind to allergens and stimulate mast cells
to release histamine and heparin Triggers allergic response
Allergy shots Small amounts of allergen stimulates production of IgG to
prevent IgE from binding to antigen IgG antibodies do not stimulate mast cells, so immune response
is not generated
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Signs/symptoms Inhaled allergens – runny nose, sneezing, coughing, wheezing Ingested allergens – nausea, vomiting, diarrhea Skin allergens – rashes Allergens in blood – most life-threatening; can affect many
organs
Treatment Antihistamines, decongestants – OTC or prescription Epinephrine for anaphylaxis – vasoconstriction, increasing BP
Anaphylaxis – life-threatening response
Major Immune System Disorders (cont.)
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Common Immune System Disorders Autoimmune disease
Body attacks its own antigens Examples
Scleroderma Rheumatoid arthritis Multiple sclerosis Glomerulonephritis Chron’s disease Diabetes mellitus, type I
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Common Immune System Disorders (cont.)
Disorder Description AIDS Development of severe signs and symptoms
caused by HIV as it destroys lymphocytes; 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
Lymphedema Blockage of lymphatic vessels results in tissue swelling that increases over time
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Common IS Disorders (cont.)
Disorder Description Mononucleosis “Mono”; highly contagious viral infection
spread through saliva of infected person
Systemic lupus erythematous (SLE)
Autoimmune disorder; antibodies produces that target own cells and tissues; affects women more often than men
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© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Apply Your Knowledge
Matching:
___ Immune response to a substance A. CFS
___ Blockage of lymphatic vessels B. SLE
___ “Kissing disease” C. Cancer
___ “Butterfly” rash on face D. Autoimmune disease
___ Severe tiredness E. Lymphedema
___ Uncontrolled growth of abnormal cells F. Mononucleosis
___ Body attack its own antigens G. Allergy
G
F
E
D
C
B
A
ANSWER:
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In Summary Immune system is the body’s major line of defense
Primary function – protect against infection, toxins, and cancer
Specific or nonspecific defenses Lymphocytes are major cells of immune system
Immune response may be primary or secondary Medical assistant must understand immune system
Aseptic technique Infection control Educate patients