chapter 22: the lymphatic system and immunity 2/18/20091
TRANSCRIPT
Chapter 22: The Lymphatic System and Immunity
2/18/2009 1
Three Parts or Sections
I. Lymphatics in general
II. Innate or nonspecific immunity
III. Adaptive or specific/memory immunity
2/18/2009 2
Immunity or Resistance
Ability to ward off damage or disease through our defenses
2 types of immunity Innate or nonspecific immunity – present at birth
No specific recognition of invaders, no memory component
1st and 2nd line of defenses Adaptive or specific immunity
Specific recognition of invaders with a memory component
2/18/2009 3
Lack of resistance is also known as: Pathogenic Innate Specific Susceptibility Lymphatic
2/18/2009 4
I. Lymphatic system structure and function
Consists of lymph, lymphatic vessels, structures and organs containing lymphatic tissue, red bone marrow
Functions of the lymphatic system1. Drain excess interstitial fluid
2. Transport dietary lipid and lipid soluble vitamins (K, E, D, and A)
3. Carry our immune responses
2/18/2009 5
Which of the following is not a function of the lymphatic and immune system? Draining excess interstitial fluid Maintaining water homeostasis in the body Transporting dietary lipids Carrying out immune responses
2/18/2009 6
What is the major difference between lymph and interstitial fluid? Composition of electrolytes White blood cells are present in lymph Location Types of proteins present Red blood cells are present in interstitial fluid
2/18/2009 7
Components of the Lymphatic System
2/18/2009 8
Lymphatic vessels and lymph circulation
Vessels begin as lymphatic capillaries Closed at one end
Unite to form large lymphatic vessels Resemble veins in structure but thinner walls
and more valves Passes through lymph nodes
Encapsulated organs with aggregates of B and T cells
Lymphatic capillaries are found throughout the body except in avascular tissue, the CNS, portions of the spleen, and red bone marrow.
2/18/2009 9
Lymphatic capillaries
Slightly large diameter that blood capillaries Unique one-way structure Permits interstitial fluid to flow in but not out Anchoring filaments pull openings wider
when interstitial fluid accumulates Small intestine has lacteal for dietary lipid
uptake Chyle is lymph with lipids
2/18/2009 10
What causes lymph from the small intestines to appear white? Proteins WBC RBC Lipids Fats
This is known as ________________.
2/18/2009 11
Lymphatic Capillaries
2/18/2009 12
Describe how lymphatic capillaries are one-way only vessels.
Ans: The ends of the endothelial cells in the wall of the lymphatic capillary overlap. When pressure is higher in the interstitial fluid than in the lymph, the cells separate slightly allowing interstitial fluid into the vessel. When pressure is greater inside, the cells are tightly packed, not allowing the lymph to cross back into the interstitial fluid.
2/18/2009 13
Lymph trunks and ducts
Vessels unite to form lymph trunks Principal trunks are the lumbar, intestinal,
bronchomediastinal, subclavian and jugular
Passes from lymph trunks into 2 main channels (thoracic and right lymphatic ducts) before draining into venous blood (subclavian veins)
2/18/2009 14
Routes for drainage of lymph
2/18/2009 15
The left subclavian vein receives lymph from Left axillary vein Lumbar trunk Jugular trunk Thoracic duct Right lymphatic duct
2/18/2009 16
Formation and flow of lymph – Starling’s Law
More fluid filters out of blood capillaries than returns to them by reabsorption
Excess filtered fluid – about 3L/day – drains into lymphatic vessels and become lymph
Important function of lymphatic vessels to return lost plasma proteins to blood stream
Contain valves Same 2 “pumps” aiding venous return also used
Skeletal muscle pump – milking action Respiratory pump – pressure changes during breathing
2/18/2009 17
What is/are important function(s) of the lymphatics?
1. Drain excess interstitial fluid
2. Transport dietary lipid
3. Carry our immune responses
4. Important function of lymphatic vessels to return lost plasma proteins to blood stream
2/18/2009 18
How is lymph moved? Valves Skeletal muscle pump Respiratory pump Venoconstriction
2/18/2009 19
The skeletal muscle and respiratory pumps are used in Lymphatic system Cardiovascular system Immune system Lymphatic and Immune systems only Lymphatic, Immune and Cardiovascular
systems
2/18/2009 20
Define Starlings Law: More fluid filters out of blood capillaries
than returns to them by reabsorption Excess filtered fluid – about 3L/day –
drains into lymphatic vessels and become lymph
85% of interstitial fluid is reabsorbed by the capillaries.
2/18/2009 21
The lymph from the right foot empties into the Left axillary vein Lumbar trunk Jugular trunk Thoracic duct Right lymphatic duct
2/18/2009 22
Describe how edema can form.
Ans: Edema can form by obstruction to lymph
flow or increased capillary blood pressure causing interstitial fluid to form faster than it is reabsorbed.
2/18/2009 23
Relationship of the Lymphatic System to the Cardiovascular System
2/18/2009 24
Lymphatic tissues and organs
2 groups based on function
1. Primary lymphatic organs Sites where stem cells divide and become
immunocompetent Red bone marrow and thymus
2. Secondary lymphatic organs Sites where most immune response occurs Lymph nodes, spleen, lymphatic nodules
2/18/2009 25
Define primary lymphatic organ: Sites where stem cells divide and become immunocompetent
List primary lymphatic organs: Red bone marrow and thymus
Define secondary lymphatic organ: Sites where most immune response occurs
List secondary lymphatic organs: Lymph nodes, spleen, lymphatic nodules
2/18/2009 26
Thymus
Thymus Outer cortex composed of large number of T cells
Immature T cells migrate here from red bone marrow where they proliferate and begin to mature - THYMOSIN
Dendritic cells derived from monocytes assist in T cell maturation
Specialized epithelial cells help educate T cells through positive selection – only about 25% survive – HASSALLS CORPUSCLES
Macrophages clear out dead and dying cells Medulla
More mature T cells migrate here from cortex More epithelial cells, dendritic cells and macrophages
Thymus shrinks with age from 70g in infants to 3g in old age
2/18/2009 27
Thymus
2/18/2009 28
Which of the below produces the hormone that promotes maturation of T cells? Spleen Lymph node Red bone marrow Thymus Pancreas
What is the hormone?
2/18/2009 29
In the thymus, where is it speculated that T cells die? Capsule Trabeculae Epithelial cells Hassall’s corpuscles T cells do not die in the thymus
2/18/2009 30
Lymph nodes
Located along lymphatic vessels Scattered throughout body Stroma – supporting connective tissue
Capsule, trabeculae, reticular fibers and fibroblasts Parenchyma – functional part
Outer cortex – aggregates of B cells called lymphatic nodules (follicles) – site of plasma cell and memory B cell formation
Inner cortex – mainly T cells and dendritic cells Medulla – B cells, antibody producing plasma
cells from cortex, and macrophages; some follicles
2/18/2009 31
Structure of a Lymph Node
2/18/2009 32
This portion of the lymph node does not contain any lymphatic nodules. Inner cortex Outer cortex Medulla Sinuses Trabeculae
2/18/2009 33
Lymph
Lymph flows through a node in 1 direction only Enters through afferent lymphatic vessels Directs lymph inward Lymph enters sinuses (irregular channels) Into medulla Medullary sinuses drain into efferent lymphatic vessels Conveys lymph, antibodies and activated T cells out of the
node Lymph nodes function as a filter
Foreign substances trapped Destroyed by macrophages or immune response of
lymphocytes
2/18/2009 34
Spleen
Largest single mass of lymphatic tissue in the body
Stroma – capsule, trabeculae, reticular fibers, and fibroblasts
Parenchyma White pulp – lymphatic tissue (lymphocytes
and macrophages) B cells and T cells carry out immune
function Red pulp
2/18/2009 35
Red Pulp
Red pulp – blood-filled venous sinuses and splenic (Bilroth’s) cords – red blood cells, macrophages, lymphocytes, plasma cells, and granulocytes1. Macrophages remove ruptured, worn out or
defective blood cells
2. Storage of up to 1/3 of body’s platelet supply
3. Production of blood cells during fetal life
2/18/2009 36
Structure of the Spleen
2/18/2009 37
Which of the following is a function of the spleen? Removes worn out blood cells Circulates lymph Cleanses interstitial fluid Cleanses lymph Traps microbes with mucus
List the other functions of the spleen. (Don’t forget white pulp!)
2/18/2009 38
Lymphatic nodules
Not surrounded by a capsule Scattered throughout lamina propria of
mucous membranes lining GI, urinary, reproductive tract
Mucosa-associated lymphatic tissue (MALT)
Most small and solitary Some larger – tonsils, Peyer’s patches,
appendix
2/18/2009 39
What is a lymphatic nodule? Not surrounded by a capsule
List sites of lymphatic nodules: Scattered throughout lamina propria of mucous
membranes lining GI, urinary, reproductive tract What is MALT?
Mucosa-associated lymphatic tissue (MALT) List the large or prominent lymphatic
nodules: Some larger – tonsils, Peyer’s patches, appendix
2/18/2009 40
II. Innate immunity
First line of defenses: Skin and mucous membranes Provide both physical and chemical barriers Physical barriers
Epidermis – closely packed, keratinized cells Periodic shedding
Mucous membranes Mucus traps microbes and foreign substances
Nose hairs trap and filter Cilia of upper respiratory tract propel trapped particles
up and out
2/18/2009 41
Innate Immunity
Fluids Lacrimal apparatus of eye
Washing action of tears Lysozyme breaks down bacterial cell walls – also present
in saliva, perspiration, nasal secretions, and tissue fluids Saliva washes mouth Urine cleanses urinary system Vaginal secretions, defecation and vomiting
Chemicals Sebaceous (oil) glands secrete sebum – protective film,
acid Perspiration, gastric juice, vaginal secretions – all acidic
2/18/2009 42
Second line of defenses: Internal defenses
Antimicrobial substances
1. Interferons Produced by lymphocytes, macrophages, and fibroblasts
infected by viruses Prevents replication in neighboring uninfected cells
2. Complement Proteins in blood plasma and plasma membranes “complement” or enhance certain immune reactions Causes cytolysis of microbes, promotes phagocytosis,
contributes to inflammation
2/18/2009 43
These anti-microbial substances promote cytolysis, phagocytosis and inflammation. Transferrins Perforins Complement proteins Defensins Interferons
2/18/2009 44
Which of these does NOT provide a physical or chemical barrier? Macrophages Saliva Urine Mucus Stratified squamous epithelium
2/18/2009 45
Describe the barriers used in innate defense. Ans: Barriers used by the innate defense
include epidermis, mucus, hairs, cilia, lacrimal apparatus, saliva, urine, vaginal secretions, sebum, perspiration and gastric juices.
2/18/2009 46
These anti-microbial substances will diffuse to uninfected cells and reduce production of viral proteins. Transferrins Perforins Complement proteins Defensins Interferons
2/18/2009 47
Internal Defenses
3. Iron-binding proteins Inhibit growth of bacteria by reducing available
iron
4. Antimicrobial proteins (AMPs) Short peptides that have a broad spectrum of
antimicrobial activity Can attract dendritic cells and mast cells that
participate in immune responses
2/18/2009 48
Internal Defenses
Natural Killer (NK) cells Lymphocyte but not a B or T cell Ability to kill wide variety of infected body cells and
certain tumor cells Attack any body cell displaying abnormal or unusual
plasma membrane proteins Can release perforin (makes perforations) or granzymes
(induce apoptosis) Phagocytes
Neutrophils and macrophages (from monocytes) Migrate to infected area 5 steps in phagocytosis
2/18/2009 49
1 MicrobeCHEMOTAXIS
Phagocyte
Phases of phagocytosis
1
Phases of phagocytosis
MicrobeCHEMOTAXIS
Pseudopod
Phagocyte
ADHERENCE2
1 MicrobeCHEMOTAXIS
Lysosome
Pseudopod
Phagocyte
ADHERENCE INGESTION2 3
Phases of phagocytosis
1 MicrobeCHEMOTAXIS
Lysosome
Digestiveenzymes
Pseudopod
Phagocyte
ADHERENCE INGESTION
Plasmamembrane
DIGESTION
2 3
4
Phases of phagocytosis
1 MicrobeCHEMOTAXIS
Lysosome
Digestiveenzymes
Pseudopod
Phagocyte
ADHERENCE INGESTION
Plasmamembrane
DIGESTION
KILLINGResidual body(indigestiblematerial)
Digested microbein phagolysosome
2 3
4
5
Phases of phagocytosis
2/18/2009 50
Phagocytosis of a microbe
These are mainly used to kill infectious microbes and tumor cells. Natural killer cells Perforins platelets Mucus Antimicrobial proteins
2/18/2009 51
Which of these provides a non-specific cellular disease resistance mechanism? Macrophages T lymphocytes B lymphocytes Memory B cells Stratified squamous epithelium
2/18/2009 52
Inflammation
Nonspecific, defensive response of body to tissue damage
4 signs and symptoms – redness, pain, heat and swelling
Attempt to dispose of microbes, prevent spread, and prepare site for tissue repair
3 basic stages1. Vasodilation and increased blood vessel
permeability
2. Emigration
3. Tissue repair
2/18/2009 53
Vasodilation and increased permeability of blood vessels
Increased diameter of arterioles allows more blood flow through area bringing supplies and removing debris
Increased permeability means substances normally retained in the blood are permitted to pass out – antibodies and clotting factors
Histamine, kinins, prostaglandins (PGs), leukotrienes (LTs), complement
2/18/2009 54
Emigration of phagocytes
Depends on chemotaxis Neutrophils predominate in early stages but
die off quickly Monocytes transform into macrophages
More potent than neutrophils Pus – pocket of dead phagocytes and
damaged tissue
2/18/2009 55
Which of the following is NOT a sign of inflammation? Redness Pain Heat Mucus production Swelling
2/18/2009 56
Which of the following intensifies the effect of interferons and promotes the rate of repair? Complement proteins Perforin Fever Macrophages Natural killer cells
2/18/2009 57
Which of the below do NOT induce vasodilation and permeability (increased fluid flow to an infection site. Histamines Kinins Perforin Leukotrienes Complement
2/18/2009 58
III. Adaptive immunity
Ability of the body to defend itself against specific invading agents
Antigens (Ags) – substances recognized as foreign and provoking an immune response
Distinguished from innate immunity by Specificity Memory
2/18/2009 59
This induces production of a specific antibody. Phagocytosis Antigen Antibody Defensin Imunnoglobulin
2/18/2009 60
2 types of adaptive immunity
Cell-mediated Cytotoxic T cells ( CD 8 or T8) directly attack
invading antigens Particularly effective against intracellular pathogens,
some cancer cells and foreign tissue transplants
Antibody-mediated B cells transform into plasma cells making antibodies
(Abs) or immunoglobulins Works against extracellular pathogens in fluids outside cells
Helper T cells ( CD4 or T4) aid in both types 2 types of immunity work together
2/18/2009 61
Maturation of T cells and B cells
Both develop from pluripotent stem cells originating in red bone marrow B cells complete their development in red bone
marrow T cells develop from pre-T cells that migrate from
red bone marrow to the thymus Helper T cells (CD4 T cells) and cytotoxic T cells
(CD8 T cells) Immunocompetence – ability to carry out
adaptive immune response Have antigen receptors to identify specific antigen
2/18/2009 62
When B and T cells are fully developed and mature, they are known to be Immunocompetent Pluripotent stem cells Primary lymphatic cells Specifically promoted Germ cells
2/18/2009 63
Cell-mediated and antibody-mediated immunity
2/18/2009 64
Clonal selection
Process by which a lymphocyte proliferates and differentiates in response to a specific antigen Clone – population of identical cells all recognizing the
same antigen as original cell
Lymphocyte undergoes clonal selection to produce Effector cell – active helper T cell, active cytotoxic T cell,
plasma cell, die after immune response Memory cell – do not participate in initial immune
response, respond to 2nd invasion by proliferating and differentiating into more effector and memory cells, long life spans
2/18/2009 65
Antigens Antigens have 2
characteristics Immunogenicity – ability to
provoke immune response Reactivity – ability of
antigen to react specifically with antibodies it provoked
Entire microbes may act as antigen
Typically, just certain small parts of large antigen molecule triggers response (epitope or antigenic determinant)
2/18/2009 66
This can only stimulate an immune response if attached to a large carrier molecule. Epitope Antigen Hapten MHC CD8
2/18/2009 67
Diversity of antigen receptors Human immune system able to recognize and
bind to at least a billion different epitopes Result of genetic recombination – shuffling and
rearranging of a few hundred versions of several small gene segments
Major Histocompatibility Complex Antigens MHC or human leukocyte antigens (HLA) Normal function to help T cells recognize foreign or self Class I MHC (MHC-I) – built into all body cells except RBCs Class II MHC (MHC-II) – only on antigen presenting cells
2/18/2009 68
Pathways of antigen processing
B cells can recognize and bind to antigens T cells must be presented with processed
antigens Antigenic proteins are broken down into peptide
fragments and associated with MHC molecules Antigen presentation – antigen-MHC complex
inserted into plasma membrane Pathway depends on whether antigen is outside or
inside body cells
2/18/2009 69
Which of the following is responsible for diversity in the immune system? Antigen receptors MHC Hapten MHC and antigen receptors Epitopes
2/18/2009 70
Exogenous and Endogenous Antigens Exogenous antigens – present in fluid
outside body cells Antigen-presenting cells (APCs) include
dendritic cells, macrophages and B cells Ingest antigen, process, place next to MHC-II
molecule in plasma membrane, and present to T cells
Endogenous antigens – antigens inside body cells Infected cell displays antigen next to MHC-I
2/18/2009 71
This class of cells includes macrophages, B cells and dendritic cells. Antigen presenting cells Primary lymphocytes T cells RBC Epitope cells
2/18/2009 72
Phagocytosis orendocytosis ofantigen
APCs present exogenous antigens in association with MHC-II molecules
Antigen-presentingcell (APC)
MHC-IIself-antigen
Antigenpeptidefragments
Key:
Exogenousantigen
1 Phagocytosis orendocytosis ofantigen
Digestion ofantigen intopeptide fragments
Phagosomeor endosome
APCs present exogenous antigens in association with MHC-II molecules
Antigen-presentingcell (APC)
MHC-IIself-antigen
Antigenpeptidefragments
Key:
1
2
Exogenousantigen
Phagocytosis orendocytosis ofantigen
Digestion ofantigen intopeptide fragments
Phagosomeor endosome
APCs present exogenous antigens in association with MHC-II molecules
Antigen-presentingcell (APC)
Synthesis of MHC-II molecules
MHC-IIself-antigen
Antigenpeptidefragments
Key:
Endoplasmicreticulum
1
3
2
Exogenousantigen
Phagocytosis orendocytosis ofantigen
Digestion ofantigen intopeptide fragments
Phagosomeor endosome
APCs present exogenous antigens in association with MHC-II molecules
Antigen-presentingcell (APC)
Packaging of MHC-IImolecules into a vesicle
Synthesis of MHC-II molecules
MHC-IIself-antigen
Antigenpeptidefragments
Key:
Endoplasmicreticulum
1
4
3
2
Exogenousantigen
Phagocytosis orendocytosis ofantigen
Digestion ofantigen intopeptide fragments
Phagosomeor endosome
APCs present exogenous antigens in association with MHC-II molecules
Antigen-presentingcell (APC)
Vesicles containing antigenpeptide fragments andMHC-II molecules fuse
Packaging of MHC-IImolecules into a vesicle
Synthesis of MHC-II molecules
MHC-IIself-antigen
Antigenpeptidefragments
Key:
Endoplasmicreticulum
1
5
4
3
2
Exogenousantigen
Phagocytosis orendocytosis ofantigen
Digestion ofantigen intopeptide fragments
Antigen peptidefragments bind toMHC-II molecules
Phagosomeor endosome
APCs present exogenous antigens in association with MHC-II molecules
Antigen-presentingcell (APC)
Vesicles containing antigenpeptide fragments andMHC-II molecules fuse
Packaging of MHC-IImolecules into a vesicle
Synthesis of MHC-II molecules
MHC-IIself-antigen
Antigenpeptidefragments
Key:
Endoplasmicreticulum
1
5
6
4
3
2
Exogenousantigen
Phagocytosis orendocytosis ofantigen
Digestion ofantigen intopeptide fragments
Antigen peptidefragments bind toMHC-II molecules
Phagosomeor endosome
APCs present exogenous antigens in association with MHC-II molecules
Antigen-presentingcell (APC)
Vesicles containing antigenpeptide fragments andMHC-II molecules fuse
Packaging of MHC-IImolecules into a vesicle
Synthesis of MHC-II molecules
MHC-IIself-antigen
Antigenpeptidefragments
Key:
Endoplasmicreticulum
Vesicle undergoesexocytosis andantigen–MHC-IIcomplexes are insertedinto plasma membrane
1
5
6
7
4
3
2
Exogenousantigen
2/18/2009 73
Exogenous Antigens
Endogenous Antigens
2/18/2009 74
Cell-mediated immunity Activation of T cells
First signal in activation T-cell receptors (TCRs) recognize and bind to a specific
foreign antigen fragments that are presented in antigen-MHC complexes
CD4 and CD8 proteins are coreceptors Second signal required for activation
Costimulation – 20 known substances (cytokines, plasma membrane molecules)
May prevent immune response from occurring accidentally Anergy – recognition without costimulation (in both B and T
cells) leads to prolonged state of inactivity
2/18/2009 75
This can only become activated when bound to a foreign antigen and simultaneously receiving costimulation. B Cell T Cell Interferon MHC Antigen presenting cell
2/18/2009 76
Activation and clonal selection of helper T cells
Most that display CD4 develop into helper T cells (CD4 T cells)
Recognize exogenous antigen fragments associated with MHC-II molecules on the surface of an APC
After activation undergoes clonal selection Makes active helper T cells and memory helper T cells Active helper T cells secrete variety of cytokines
Interleukin-2 (IL-2) needed for virtually all immune responses
Memory helper T cells are not active cells – can quickly proliferate and differentiate if the antigen appears again
2/18/2009 77
These display CD 4 in their membrane and are associated with MHC class II molecules. Cytotoxic T cells Helper T Cells Memory T Cells MHC B cells
2/18/2009 78
Activation and clonal selection of a helper T cell
2/18/2009 79
Activation and clonal selection of cytotoxic T cells
Most that display CD8 develop into cytotoxic T cells (CD8 T cells)
Recognize antigens combined with MHC-I Maximal activation also requires presentation of
antigen with MHC-II to cause helper T cells to produce IL-2
Undergoes clonal selection Active cytotoxic T cells attack body cells Memory cytotoxic T cells do not attack but wait for
a antigen to appear again
2/18/2009 80
Activation and clonal selection of a cytoxic T cell
2/18/2009 81
Elimination of invaders Cytotoxic T cells migrate to seek out and destroy
infected target cells Kill like natural killer cells Major difference is T cells have specific receptor
for particular microbe while NK cells destroy a wide variety of microbe-infected cells
2 ways to kill cells Granzymes cause apoptosis Perforin and/ or granulysin causes cytolysis
Immunological surveillance Tumor antigens displayed on cancerous cells targeted by
cytotoxic T cells, macrophages and natural killer cells
2/18/2009 82
Activity of cytoxic T cells
2/18/2009 83
Antibody-mediated immunity
Activation and clonal selection of B cells During activation, antigen binds to B cell receptor (BCRs) Can respond to unprocessed antigen Response much more intense when B cell processes
antigen Antigen taken into B cell, combined with MHC-II, moved to
plasma membrane, helper T cell binds and delivers costimulation (interleukin-2 and other cytokines)
B cell undergoes clonal selection Plasma cells secrete antibodies Memory B cells do not secrete antibodies but wait for
reappearance of antigen
2/18/2009 84
Activation and clonal selection of B cells
2/18/2009 85
Antibodies (Ab)
Can combine specifically with epitope of the antigen that triggered its production
Belong to group of glycoproteins called globulins Ab are immunoglobulins (Igs)
4 polypeptide chains – 2 heavy (H) chains, 2 light (L) chains
Hinge region – antibody can be T shape or Y shape Variable (V) region at tips of each H and L chain
2 antigen-binding sites - bivalent Constant (C) region – remainder of H and L chain
Same in each 5 classes – determines type of reaction
2/18/2009 86
Chemical structure of the immunoglobin (IgG) class of antibody
2/18/2009 87
Click to edit Master title style22_table_03
Antibody actions
Neutralizing antigen Immobilizing bacteria Agglutinating and precipitating antigen Enhancing phagocytosis Activating complement
Defensive system of over 30 proteins Destroy microbes by causing phagocytosis, cytolysis, and
inflammation Acts in a cascade – one reaction triggers another Activate C3 C3 then begins cascade that brings about phagocytosis,
cytolysis, and inflammation
2/18/2009 89
Immunological memory
Thousands of memory cells exist after initial encounter with an antigen
Next time antigen appears can proliferate and differentiate within hours
Antibody titer measure of immunological memory Amount of Ab in serum
Primary response Secondary response faster
and stronger
2/18/2009 90
List the five actions of antibodies.
Ans: Antibodies can act as a neutralizing agent, they can immobilize bacteria, agglutinate and precipitate the antigen, activate the complement and enhance phagocytosis.
2/18/2009 91
This class of antibodies is mainly found in sweat, tears, breast milk and GI secretions. IgG IgA IgM IgD IgE
2/18/2009 92
This will lead to inflammation, enhancement of phagocytosis and bursting of microbes. Classical complement system Alternative complement system Apoptosis Classical and Alternative complement systems Hapten activation
2/18/2009 93
This action makes microbes more susceptible to phagocytosis. Opsonization Cytolysis Inflammation Complement Hybridoma
2/18/2009 94
Click to edit Master title style22_table_04
Self-recognition and self-tolerance Your T cells must have
Self-recognition – be able to recognize your own MHC Self-tolerance – lack reactivity to peptide fragments from
your own proteins Pre-T cells in thymus develop self-recognition via
positive selection – cells that can’t recognize your own MHC undergo apoptosis
Self-tolerance occurs through negative selection in which T and B cells that recognize self peptide fragments are eliminated Deletion – undergo apoptosis Anergy – remain alive but are unresponsive
2/18/2009 96
This is a self-responsive cell that is inactive. Deleted cell Hybridoma cell Epitopic cell Anergy cell Natural killer cell
2/18/2009 97
Click to edit Master title style22_table_05
This is characterized by the inability of the immune system to protect the body from a pathogen. immunodeficiency diseases allergy autoimmune disease transplantations graft
A natural exposure to an infectious agent leads to: A. Passive immunity B. Active immunity Both a and b None of the above
2/18/2009 100
This class of antibodies is produced after an initial exposure to antigens. IgA IgE IgM IgD IgG
2/18/2009 101
Of the following which is considered the body’s second major defense. Mucous cells Germ cells Lymphocytes Natural killer cells None of the above
2/18/2009 102
An acute allergic response can lead to: transplantation retroviruses anaphylactic shock passive immunity active immunity
2/18/2009 103
This is a small hormone that can stimulate or inhibit many normal cell functions. Enzyme Kinins Cytokine MHC Leukocyte
2/18/2009 104
DISORDERS: HOMEOSTATIC IMBALANCES Discuss AIDS in terms of epidemiology,
pathogenesis of the HIV virus, signs and symptoms, progression to AIDS, and treatment.
Discuss the basic types of allergic reactions. Discuss the causes and symptoms of infectious
mononucleosis. Discuss the causes and treatments of
autoimmune diseases. Discuss the two basic types of lymphomas. Discuss the causes and treatments of systemic
lupus erythematosus.
2/18/2009 105
End of Chapter 22
Copyright 2009 John Wiley & Sons, Inc.All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permission Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publishers assumes no responsibility for errors, omissions, or damages caused by the use of theses programs or from the use of the information herein.
2/18/2009 106