anatomy lecture 10 - lymphatic and immune
DESCRIPTION
Anatomy Lecture 10 - Lymphatic and ImmuneTRANSCRIPT
Essentials of Human Anatomy & Physiology
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slides 12.23 – 12.52
Seventh EditionElaine N. Marieb
Chapter 12The Lymphatic System
and Body Defenses
FeverFever
Slide 12.23Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Abnormally high body temperature Hypothalmus heat regulation
can be reset upward in response to pyrogens (secreted by white blood cells)
High temperatures inhibit the release of iron and zinc from liver and spleen needed by bacteria for reproduction
Fever also increases the speed of tissue repair (due to higher metabolic rate of tissues)
Specific Defense: The Immune Specific Defense: The Immune System – Third Line of DefenseSystem – Third Line of Defense
Antigen specific – recognizes and acts against particular foreign substances
Systemic – not restricted to the initial infection site
Has memory – recognizes and mounts a stronger attack on previously encountered pathogens
Types of ImmunityTypes of Immunity
Slide 12.25Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Humoral immunity (operates in fluids of body) Antibody-mediated immunity Cells produce chemicals for
defense Cellular immunity (lymphocytes
themselves defend the body) Cell-mediated immunity Cells target virus infected cells,
cancer cells, cells of foreign grafts
Humoral vs. Cell-Mediated Response
Antigens (Nonself)Antigens (Nonself)
Slide 12.26Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Any substance capable of exciting the immune system and provoking an immune response
Examples of common antigens Foreign proteins Nucleic acids Large carbohydrates Some lipids Pollen grains Microorganisms
Self-AntigensSelf-Antigens
Slide 12.27Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Human cells have many surface proteins
Our immune cells do not attack our own proteins
Our cells in another person’s body can trigger an immune response because they are foreignRestricts donors for transplants
AllergiesAllergies
Slide 12.28Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Many small molecules (called haptens or incomplete antigens) are not antigenic, but link up with our own proteins
The immune system may recognize and respond to a protein-hapten combination
The immune response is harmful rather than protective because it attacks our own cells
Cells of the Immune SystemCells of the Immune System
Slide 12.29
Lymphocytes Originate from
hemocytoblasts in the red bone marrow
B lymphocytes become immunocompetent in the bone marrow
T lymphocytes become immunocompetent in the thymus
Immunocompetence-capability to respond to a certain antigen by binding to it
Cells of the Immune SystemCells of the Immune System
Slide 12.29Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Macrophages Arise from cells formed in the bone marrow “big” eaters that engulf foreign particles and
present fragments of these particles on their cell surfaces
Become widely distributed in lymphoid organs
Activation of LymphocytesActivation of Lymphocytes
Slide 12.30Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 12.9
Humoral (Antibody-Mediated) Immune Humoral (Antibody-Mediated) Immune ResponseResponse
Slide 12.31aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
B lymphocytes with specific receptors bind to a specific antigen
The binding event activates the lymphocyte to undergo clonal selection
A large number of clones are produced (primary humoral response)
Humoral (Antibody-Mediated) Immune Humoral (Antibody-Mediated) Immune ResponseResponse
Slide 12.31aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Most B cells become plasma cells Produce antibodies
to destroy antigens Activity lasts for
four or five days Some B cells become
long-lived memory cells (secondary humoral response)
Humoral Immune ResponseHumoral Immune Response
Slide 12.32Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 12.10
Secondary Response (after exposure to Secondary Response (after exposure to the same antigen) --can be years laterthe same antigen) --can be years later
Slide 12.33Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Memory cells are long-lived
A second exposure causes a rapid response (since all preparations for the attack have been made)
The secondary response is stronger and longer lasting Figure 12.11
Humoral Immune ResponseHumoral Immune Response
Slide 12.32Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 12.10
New army being made
Active Immunity-acquired when…Active Immunity-acquired when…
Slide 12.34Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Your B cells encounter antigens and produce antibodies
Active immunity can be naturally or artificially acquired
Figure 12.12
Passive ImmunityPassive Immunity
Slide 12.35Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Antibodies are obtained from someone else Conferred naturally from a
mother to her fetus, and to baby through milk
Conferred artificially from immune serum or gamma globulin (usu. for hepatitis)
Immunological memory does not occur
Protection provided by “borrowed antibodies”
Monoclonal Antibodies-one group of Monoclonal Antibodies-one group of borrowed antibodiesborrowed antibodies
Slide 12.36Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Antibodies prepared for clinical testing or diagnostic services
Produced from descendants of a single cell line, and exhibit specificity for one and only one antigen
Examples of uses for monoclonal antibodies Deliver cancer-fighting drugs to cancerous
tissues Diagnosis of hepatitis and rabies
Antibodies (Immunoglobulins) (Igs)Antibodies (Immunoglobulins) (Igs)
Slide 12.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Soluble proteins secreted by B cells (plasma cells)
Carried in blood plasma Capable of binding specifically to an
antigen
Antibody StructureAntibody Structure
Slide 12.38aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Four amino acid chains linked by disulfide bonds
Two identical amino acid chains are linked to form a heavy chain
Figure 12.13b
Antibody StructureAntibody Structure
Slide 12.38bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
The other two identical chains are light chains
Specific antigen-binding sites are present
Figure 12.13b
Antibody ClassesAntibody Classes
Slide 12.39Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Antibodies of each class have slightly different roles
Five major immunoglobulin classes IgM – can fix complement IgA – found mainly in mucus IgD – important in activation of B cell IgG – can cross the placental barrier IgE – involved in allergies
Antibody FunctionAntibody Function
Slide 12.40Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Antibodies inactivate antigens in a number of ways Complement fixation Neutralization Agglutination Precipitation
Antibody FunctionAntibody Function
Slide 12.41Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 12.14
Cellular (Cell-Mediated) Immune Cellular (Cell-Mediated) Immune ResponseResponse
Slide 12.42Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Antigens must be presented by macrophages to an immunocompetent T cell (antigen presentation)
T cells must recognize nonself and self (double recognition)
After antigen binding, clones form as with B cells, but different classes of cells are produced
Cellular (Cell-Mediated) Immune Cellular (Cell-Mediated) Immune ResponseResponse
Slide 12.43Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 12.15
T Cell ClonesT Cell Clones
Slide 12.44aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Cytotoxic T cells Specialize in killing infected cells Insert a toxic chemical (perforin)
Helper T cells Recruit other cells to fight the invaders Interact directly with B cells
T Cell ClonesT Cell Clones
Slide 12.44bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Suppressor T cells Release chemicals to suppress the activity
of T and B cells Stop the immune response to prevent
uncontrolled activity
A few members of each clone are memory cells
Summary of the Immune ResponseSummary of the Immune Response
Slide 12.45Copyright © 2003 Pearson Education, Inc. publishing as Benjamin CummingsFigure 12.16
Organ Transplants and RejectionOrgan Transplants and Rejection
Slide 12.46aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Major types of grafts Autografts – tissue transplanted from one
site to another on the same person Isografts – tissue grafts from an identical
person (identical twin) Allografts – tissue taken from an unrelated
person Xenografts – tissue taken from a different
animal species
Organ Transplants and RejectionOrgan Transplants and Rejection
Slide 12.46bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Autografts and isografts are ideal donors
Xenografts are never successful Allografts are more successful with a
closer tissue match
Disorders of Immunity: Allergies Disorders of Immunity: Allergies (Hypersensitivity)(Hypersensitivity)
Slide 12.47aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Abnormal, vigorous immune responses Types of allergies
Immediate hypersensitivity Triggered by release of histamine from IgE
binding to mast cells Reactions begin within seconds of contact with
allergen Anaphylactic shock – dangerous, systemic
response
Disorders of Immunity: Allergies Disorders of Immunity: Allergies (Hypersensitivity)(Hypersensitivity)
Slide 12.47bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Types of allergies (continued) Delayed hypersensitivity
Triggered by the release of lymphokines from activated helper T cells
Symptoms usually appear 1–3 days after contact with antigen
Allergy MechanismsAllergy Mechanisms
Slide 12.48Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 12.17
Disorders of Immunity: Disorders of Immunity: ImmunodeficienciesImmunodeficiencies
Slide 12.49Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Production or function of immune cells or complement is abnormal
May be congenital or acquired Includes AIDS – Acquired Immune
Deficiency Syndrome
Disorders of Immunity: Autoimmune Disorders of Immunity: Autoimmune DiseasesDiseases
Slide 12.50aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
The immune system does not distinguish between self and nonself
The body produces antibodies and sensitized T lymphocytes that attack its own tissues
Disorders of Immunity: Autoimmune Disorders of Immunity: Autoimmune DiseasesDiseases
Slide 12.50bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Examples of autoimmune diseases Multiple sclerosis – white matter of brain
and spinal cord are destroyed Myasthenia gravis – impairs
communication between nerves and skeletal muscles
Juvenile diabetes – destroys pancreatic beta cells that produce insulin
Rheumatoid arthritis – destroys joints
Disorders of Immunity: Autoimmune Disorders of Immunity: Autoimmune DiseasesDiseases
Slide 12.50cCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Examples of autoimmune diseases (continued) Systemic lupus erythematosus (SLE) –
affects kidney, heart, lung and skin Glomerulonephritis – impairment of renal
function
Self Tolerance BreakdownSelf Tolerance Breakdown
Slide 12.51aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Inefficient lymphocyte programming Appearance of self-proteins in the
circulation that have not been exposed to the immune system Eggs Sperm Eye lens
Self Tolerance BreakdownSelf Tolerance Breakdown
Slide 12.51bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Cross-reaction of antibodies produced against foreign antigens with self-antigens Rheumatic fever
Developmental Aspects of the Developmental Aspects of the Lymphatic System and Body DefensesLymphatic System and Body Defenses
Slide 12.52Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Except for thymus and spleen, the lymphoid organs are poorly developed before birth
A newborn has no functioning lymphocytes at birth; only passive immunity from the mother
If lymphatics are removed or lost, severe edema results, but vessels grow back in time