p.6
Functions of Different Types of Lymphocytes
What is the function of cytokine-activated phagocytes?
They kill ingested microbes.
p.10
Properties of Adaptive Immune Responses
What occurs to immune responses as infections are eliminated?
They are self-limited and decline, allowing the system to return to homeostasis.
p.4
Mechanisms of Humoral and Cell-Mediated Immunity
How does innate immunity respond to microbial entry?
It is always present and rapidly eliminates microbes that enter host tissues.
p.2
Definition and Importance of Immunity
What is the most important physiologic function of the immune system?
To prevent and eradicate infections.
p.5
Mechanisms of Humoral and Cell-Mediated Immunity
What is the function of phagocytes in innate immunity?
They engulf and show microbes within 6 to 12 hours after infection.
p.13
Clonal Selection and Expansion of Lymphocytes
What happens when naive lymphocytes recognize microbial antigens?
They proliferate and differentiate into effector cells and memory cells.
p.13
Functions of Different Types of Lymphocytes
What is the primary function of B lymphocytes?
Antibody production (humoral immunity).
p.6
Functions of Different Types of Lymphocytes
What is the role of Cytotoxic T lymphocytes (CTLs)?
They kill infected cells and eliminate reservoirs of infection.
p.2
Definition and Importance of Immunity
What is the effect of defective immune responses on individuals?
Increased risk for serious, often life-threatening infections.
p.1
Definition and Importance of Immunity
What does the term immunity refer to?
Protection against infectious pathogens and reactions to some noninfectious substances.
p.6
Mechanisms of Humoral and Cell-Mediated Immunity
What mediates humoral immunity?
Antibodies produced by B lymphocytes.
p.4
Properties of Adaptive Immune Responses
What is the role of immunologic memory in adaptive immunity?
It enhances responses upon repeat exposures to the same microbe.
p.5
Types of Immune Responses: Innate vs. Adaptive
What are the two mechanisms of adaptive immunity?
Humoral immunity and cell-mediated immunity.
p.5
Humoral and Cell-Mediated Immunity
What do B lymphocytes secrete in humoral immunity?
Antibodies that eliminate extracellular microbes.
p.5
Humoral and Cell-Mediated Immunity
What is the function of antibodies in humoral immunity?
They prevent infections and eliminate extracellular microbes.
p.14
Components of the Immune System
Where do lymphocytes develop from precursors?
In the generative lymphoid organs (bone marrow and thymus).
p.14
Properties of Adaptive Immune Responses
What are the important characteristics of naive, effector, and memory cells?
They differ in function and lifespan, with memory cells being long-lived.
p.12
Functions of Different Types of Lymphocytes
What role do lymphocytes play in recognizing infected cells?
Lymphocytes recognize peptides displayed by infected or tumor cells and kill these cells.
p.6
Passive vs. Active Immunity
How is active immunity induced?
By exposure to microbial antigens through infection or vaccination.
p.12
Components of the Immune System
What are the main classes of lymphocytes in the adaptive immune system?
B lymphocytes, helper T lymphocytes, cytotoxic T lymphocytes, and regulatory T lymphocytes.
p.5
Types of Immune Responses: Innate vs. Adaptive
What type of microbes are targeted by cell-mediated immunity?
Intracellular microbes that survive inside host cells.
p.8
Functions of Different Types of Lymphocytes
What is the difference between primary and secondary immune responses?
Secondary responses are larger, more rapid, and better at eliminating the antigen compared to primary responses.
p.7
Passive vs. Active Immunity
How long does passive immunity last?
Only for as long as the transferred antibodies are present in the body.
p.7
Properties of Adaptive Immune Responses
What is the significance of specificity in adaptive immune responses?
It allows the immune system to distinguish millions of different antigens and respond specifically to the infecting microbe.
p.14
Clonal Selection and Expansion of Lymphocytes
What happens to naive lymphocytes if they are not activated by an antigen?
They die by apoptosis after several months to a few years and are replaced by new cells.
p.10
Mechanisms of Humoral and Cell-Mediated Immunity
What types of antibodies are formed in response to antigens?
Anti-X antibody and anti-Y antibody.
p.5
Mechanisms of Humoral and Cell-Mediated Immunity
What role do epithelial barriers play in innate immunity?
They prevent microbe entry shortly after infection.
p.6
Functions of Different Types of Lymphocytes
How do helper T lymphocytes aid in defense against extracellular microbes?
By recruiting phagocytes to sites of infection.
p.5
Mechanisms of Humoral and Cell-Mediated Immunity
How do T lymphocytes function in cell-mediated immunity?
They secrete cytokines to activate phagocytes and kill infected cells.
p.12
Functions of Different Types of Lymphocytes
What is the function of regulatory T cells?
Regulatory T cells limit the activation of other lymphocytes, particularly T cells, and prevent autoimmunity.
p.3
Immunologic Disorders: Autoimmunity and Allergies
What leads to chronic inflammation in autoimmune diseases?
The inciting antigens cannot be eliminated.
p.1
Definition and Importance of Immunity
What are the implications of immune responses in health?
They can protect against infections and tumors but can also lead to pathologic inflammation and diseases.
p.9
Role of Vaccination in Disease Prevention
What is the role of vaccines in immunologic memory?
Vaccines confer long-lasting protection against infections through the activation of memory cells.
p.9
Properties of Adaptive Immune Responses
What are the characteristics of adaptive immune responses?
They are specialized to defend against different kinds of microbes and at different sites of infections.
p.4
Types of Immune Responses: Innate vs. Adaptive
What are the two types of immunity involved in defense against infections?
Innate immunity and adaptive immunity.
p.4
Properties of Adaptive Immune Responses
What is the primary function of adaptive immunity?
It adapts to the presence of microbial invaders through the proliferation and differentiation of lymphocytes.
p.10
Components of the Immune System
From where are most immune system cells derived?
Progenitors in the bone marrow.
p.13
Mechanisms of Humoral and Cell-Mediated Immunity
What is the role of major histocompatibility complex (MHC) molecules?
They display peptide fragments of protein antigens to T lymphocytes.
p.4
Mechanisms of Humoral and Cell-Mediated Immunity
What happens if microbes breach the epithelial barriers?
Components of the innate immune system, such as phagocytes and the complement system, defend against them.
p.4
Functions of Different Types of Lymphocytes
What is the role of phagocytes in innate immunity?
They eliminate microbes that have breached the body’s barriers.
p.8
Properties of Adaptive Immune Responses
What is the significance of specificity in adaptive immune responses?
It ensures that immune responses are precisely targeted to microbial pathogens.
p.8
Properties of Adaptive Immune Responses
How does diversity contribute to the immune system?
It enables the immune system to respond to a large variety of antigens.
p.12
Mechanisms of Humoral and Cell-Mediated Immunity
How do B lymphocytes recognize antigens?
Microbes bind to B lymphocytes through their Y-shaped receptors.
p.11
Functions of Different Types of Lymphocytes
What are the major functions of B lymphocytes?
Mediators of humoral immunity and specific recognition of antigens.
p.12
Mechanisms of Humoral and Cell-Mediated Immunity
What are the effector functions of cytotoxic T lymphocytes?
Killing of infected cells.
p.11
Properties of Adaptive Immune Responses
What do memory B cells represent in the antibody response?
They are indicated by the troughs formed after the peaks.
p.4
Definition and Importance of Immunity
What is another name for innate immunity?
Natural immunity or native immunity.
p.6
Mechanisms of Humoral and Cell-Mediated Immunity
Where do secreted antibodies enter?
Circulation, extracellular tissue fluids, and lumens of mucosal organs.
p.8
Clonal Selection and Expansion of Lymphocytes
What does the clonal selection hypothesis predict?
Clones of lymphocytes specific for different antigens develop before encountering those antigens.
p.1
Components of the Immune System
What is the immune system?
A collection of cells, tissues, and molecules that mediate reactions to pathogens and other substances.
p.2
Properties of Adaptive Immune Responses
What does herd immunity refer to?
When a large fraction of the population develops immunity through vaccination or natural infection.
p.2
Types of Immune Responses: Innate vs. Adaptive
Why did the influenza pandemic of 1918 and COVID-19 cause widespread infections?
Because populations had not been previously exposed and were hence not immune.
p.5
Definition and Importance of Immunity
What is an antigen?
Any molecule specifically recognized by lymphocytes or antibodies.
p.2
Types of Immune Responses: Innate vs. Adaptive
What is an obstacle to transplantation and gene therapy?
Immune responses recognizing and responding to tissue grafts and newly introduced proteins.
p.8
Clonal Selection and Expansion of Lymphocytes
What is clonal expansion?
The marked proliferative expansion of the clone of lymphocytes specific for any antigen upon exposure to that antigen.
p.15
Functions of Different Types of Lymphocytes
What do plasmablasts develop into?
Long-lived plasma cells in the bone marrow.
p.9
Immunologic Disorders: Autoimmunity and Allergies
What happens when there is a failure of self-tolerance?
It leads to autoimmune diseases.
p.7
Clonal Selection and Expansion of Lymphocytes
What distinguishes each lymphocyte clone?
All cells of one clone express identical antigen receptors, which are different from the receptors of other clones.
p.13
Functions of Different Types of Lymphocytes
What are the two main types of T lymphocytes and their functions?
CD4+ T cells help B lymphocytes and phagocytes; CD8+ T cells kill cells harboring microbes.
p.10
Components of the Immune System
What are the two broad classifications of immune cells?
Myeloid cells and lymphoid cells (lymphocytes).
p.4
Components of the Immune System
What are the first lines of defense in innate immunity?
Epithelial barriers, antimicrobial substances, and certain immune cells.
p.3
Immunologic Disorders: Autoimmunity and Allergies
What trends are observed in pertussis cases compared to historical maximums?
18,617 cases in 2019, compared to a maximum of 265,269 in 1934.
p.3
Immunologic Disorders: Autoimmunity and Allergies
What is a notable characteristic of the immune response toward self molecules?
The immune system does not normally respond to self molecules.
p.15
Functions of Different Types of Lymphocytes
What is the role of helper T cells (CD4+ T cells)?
They produce cytokines that activate B cells, macrophages, and other cell types.
p.9
Properties of Adaptive Immune Responses
How does each exposure to a microbe affect memory cells?
It generates more memory cells and activates previously generated memory cells.
p.9
Immunologic Disorders: Autoimmunity and Allergies
What is immunologic tolerance?
The immune system's unresponsiveness to self antigens, allowing coexistence with potentially antigenic self molecules.
p.7
Properties of Adaptive Immune Responses
What is meant by the lymphocyte repertoire?
The total collection of lymphocyte specificities, which is extremely diverse and allows the immune system to react to many pathogens.
p.13
Functions of Different Types of Lymphocytes
What unique surface receptors do B lymphocytes express?
Membrane-bound antibodies that recognize antigens.
p.5
Types of Immune Responses: Innate vs. Adaptive
When does innate immunity respond after infection?
It responds immediately, within hours after infection.
p.14
Components of the Immune System
What types of lymphocytes are formed in the bone marrow and thymus?
Immature B lymphocytes in the bone marrow and naive T lymphocytes in the thymus.
p.5
Mechanisms of Humoral and Cell-Mediated Immunity
What triggers adaptive immunity?
Microbes attaching to B lymphocytes or T lymphocytes.
p.15
Functions of Different Types of Lymphocytes
What are the three main types of T lymphocytes?
Naïve cells, activated or eTector lymphocytes, and memory lymphocytes.
p.11
Types of Immune Responses: Innate vs. Adaptive
What do the two curves plotted in the serum antibody titer graph represent?
They represent primary and secondary antibody responses to antigens X and Y over weeks.
p.2
Immunologic Disorders: Autoimmunity and Allergies
What is a challenge in controlling HIV/AIDS?
There is no herd immunity or effective vaccine.
p.11
Types of Immune Responses: Innate vs. Adaptive
What is indicated by the region below the second peak in the second curve?
Secondary anti-X response.
p.12
Mechanisms of Humoral and Cell-Mediated Immunity
What are the effector functions of B lymphocytes?
Neutralization of microbes, phagocytosis, and complement activation.
p.7
Passive vs. Active Immunity
What is the difference between an immune individual and a naive individual regarding a microbe?
An immune individual has been exposed to the microbe's antigens, while a naive individual has not.
p.11
Functions of Different Types of Lymphocytes
How do helper T cells contribute to the immune response?
They recognize peptides displayed by MHC molecules and secrete cytokines to stimulate various immune mechanisms.
p.12
Properties of Adaptive Immune Responses
What are the markers of CD8 positive cytotoxic T lymphocytes?
CD3 positive, CD4 negative, CD8 positive.
p.5
Types of Immune Responses: Innate vs. Adaptive
What are the two main types of immunity?
Innate immunity and adaptive immunity.
p.14
Functions of Different Types of Lymphocytes
What type of cells do B lymphocytes differentiate into after activation?
Antibody-secreting plasma cells.
p.14
Properties of Adaptive Immune Responses
What additional signals do naive lymphocytes need to proliferate and differentiate?
Signals in addition to antigens (specific signals not shown).
p.8
Properties of Adaptive Immune Responses
What are the key features of adaptive immune responses?
Specificity, diversity, memory, and nonreactivity to self.
p.6
Properties of Adaptive Immune Responses
What do T cells primarily recognize?
Peptide fragments of protein antigens presented on cell surfaces.
p.6
Passive vs. Active Immunity
What is passive immunity?
Immunity conferred by the transfer of antibodies from an actively immunized individual.
p.15
Functions of Different Types of Lymphocytes
What are the effector functions of activated or eTector T lymphocytes?
Cytokine secretion and cytotoxic activity.
p.1
Functions of Different Types of Lymphocytes
How does the immune system affect tissue repair?
It controls tissue regeneration and scarring.
p.15
Properties of Adaptive Immune Responses
How do memory cells differ from effector T lymphocytes?
Memory cells can survive for long periods in the absence of antigen, while effector T lymphocytes are short-lived.
p.9
Clonal Selection and Expansion of Lymphocytes
What is clonal selection in adaptive immunity?
The process where a specific antigen selects a preexisting clone of lymphocytes with identical receptors to proliferate and differentiate.
p.6
Mechanisms of Humoral and Cell-Mediated Immunity
How do antibodies defend against microbes?
By preventing them from infecting tissue cells and neutralizing toxins.
p.2
Role of Vaccination in Disease Prevention
What is the most effective method for protecting individuals against infections?
Stimulating immune responses through vaccination.
p.10
Mechanisms of Humoral and Cell-Mediated Immunity
What roles do antigen-presenting cells (APCs) serve in adaptive immunity?
They help to initiate immune responses.
p.10
Functions of Different Types of Lymphocytes
What is unique about lymphocytes in the immune system?
They produce clonally distributed receptors specific for diverse antigens.
p.10
Functions of Different Types of Lymphocytes
How are different types of lymphocytes distinguished?
By the expression of surface molecules recognized by monoclonal antibodies.
p.2
Role of Vaccination in Disease Prevention
What have vaccines against SARS-CoV-2 reduced?
The risks for developing a severe case of COVID-19.
p.1
Role of Vaccination in Disease Prevention
What can vaccination accomplish?
It boosts immune defenses and protects against infections.
p.9
Properties of Adaptive Immune Responses
Why is immunologic memory important?
It optimizes the immune system's ability to combat persistent and recurrent infections.
p.7
Passive vs. Active Immunity
What characterizes passive immunity?
A naive individual receives antibodies from another immune individual or from laboratory-produced protective antibodies.
p.7
Passive vs. Active Immunity
What is a physiological example of passive immunity?
Newborns receiving antibodies from their mothers through the placenta and breast milk.
p.7
Components of the Immune System
How many B and T lymphocytes are present in an adult?
About 0.5 to 1 × 10^12 B and T lymphocytes.
p.13
Immunologic Disorders: Autoimmunity and Allergies
What is the role of regulatory T lymphocytes?
To prevent or limit immune responses.
p.13
Components of the Immune System
What are the generative (primary) lymphoid organs?
The bone marrow and thymus where mature lymphocytes are produced.
p.10
Components of the Immune System
What is the significance of the CD numeric designation?
It delineates surface proteins that define a particular cell type or stage of cell differentiation.
p.8
Properties of Adaptive Immune Responses
What is immunologic memory?
The ability of the adaptive immune system to mount faster and more effective responses to repeated exposures to the same antigen.
p.8
Functions of Different Types of Lymphocytes
What initiates the primary immune response?
Naive lymphocytes encountering the antigen for the first time.
p.12
Mechanisms of Humoral and Cell-Mediated Immunity
What activates helper T lymphocytes?
Microbial antigens presented by antigen presenting cells and cytokines.
p.3
Immunologic Disorders: Autoimmunity and Allergies
What type of therapy is used for autoimmune diseases like rheumatoid arthritis?
Therapeutic blockade of cytokines.
p.12
Properties of Adaptive Immune Responses
What are the difference in percentages of CD4 positive helper T lymphocytes in blood vs lymph nodes?
In blood, it's 35-60% and in lymph nodes, it's 50-60%.
p.9
Clonal Selection and Expansion of Lymphocytes
What is the significance of diverse receptors in lymphocytes?
They arise in generative lymphoid organs to recognize a wide variety of antigens.
p.1
Definition and Importance of Immunity
What is immunology?
The study of the immune system and its functions.
p.1
Role of Vaccination in Disease Prevention
How does the immune system relate to cancer treatment?
It can prevent tumor growth and stimulate immune responses against tumor cells, foundational for cancer immunotherapy.
p.1
Immunologic Disorders: Autoimmunity and Allergies
What are some consequences of abnormal immune responses?
They can cause inflammatory diseases, allergies, autoimmune diseases, and damage transplanted tissues.
p.1
Definition and Importance of Immunity
What role does the immune system play in infections?
It is the primary defense against infections, and deficient immunity increases susceptibility to infections.
p.11
Mechanisms of Humoral and Cell-Mediated Immunity
What role do naïve B cells play in the primary anti-X response?
They produce anti-X antibodies that bind to anti-Y B cells.
p.3
Immunologic Disorders: Autoimmunity and Allergies
What is a significant factor in the morbidity associated with COVID-19?
Inflammatory responses to the virus.
p.8
Clonal Selection and Expansion of Lymphocytes
How many lymphocytes are typically specific for any one antigen before exposure?
As few as 1 in 100,000 or 1 in 1,000,000 lymphocytes.
p.11
Components of the Immune System
What types of cells are included in myeloid cells?
Neutrophils, macrophages, dendritic cells, and mast cells.
p.9
Properties of Adaptive Immune Responses
What generates immunologic memory?
Activation of memory lymphocytes, which are long-lived cells induced during the primary immune response.
p.11
Functions of Different Types of Lymphocytes
What is the function of dendritic cells?
Antigen presentation to T cells and initiation of T cell responses.
p.12
Functions of Different Types of Lymphocytes
What is the primary function of regulatory T lymphocytes?
Suppression of other lymphocytes.
p.7
Passive vs. Active Immunity
How is passive immunity clinically useful?
It can treat immunodeficiency diseases and provide emergency treatment for some viral infections and snakebites.
