Chapter 16 Study Quiz

What is adaptive immunity?

The body’s ability to recognize and defend against specific invaders and their products.

What are the five attributes (characteristics) of adaptive immunity?

Specificity, inducibility, clonality, unresponsiveness to self, and memory.

What the attribute of specificity?

Act against specific pathogens

What the attribute of inducibility?

specific pathogen activates or induced
cells of adaptive immunity

What the attribute of clonality?

once induced , cells of adaptive immunity
proliferate to form many generation of nearly identical cells

What the attribute of unresponsiveness to self?

being self-tolerant

What the attribute of memory?

having immunological memory for specific pathogens

What are the two types of adaptive immune responses?

Cell-mediated immune responses and antibody (humoral) immune responses.

What are the two main types of lymphocytes?

B lymphocytes (B cells) and T lymphocytes (T cells).

Where do B and T cells mature?

B cells in bone marrow; T cells in thymus.

What does the lymphatic system do?

Screens body tissues for foreign antigens.

What is lymph?

A fluid like plasma that arises from fluid leaked from blood vessels into tissues.

What are the primary lymphoid organs?

Red bone marrow and thymus.

What are the secondary lymphoid organs?

Lymph nodes, spleen, tonsils, and MALT.

What are antigens?

Molecules recognized by the immune system as foreign and worth attacking.

What are epitopes?

Specific parts of antigens that immune cells recognize.

What are the three types of antigens?

Exogenous, endogenous, and autoantigens.

What are MHC proteins?

Glycoproteins that present antigenic epitopes to immune cells.

What are the two classes of MHC proteins?

MHC I (all nucleated cells) and MHC II (only on APCs (antigen presenting cells) ).

What are antigen-presenting cells (APCs)?

Cells like macrophages and dendritic cells that process and present antigens via MHC II.

What is the difference between endogenous and exogenous antigen processing?

Endogenous antigens are processed within infected cells for MHC I; exogenous are taken in by APCs and presented on MHC II.

Where are T cells produced and matured?

Produced in bone marrow; mature in thymus.

What are T cell receptors (TCRs)?

Proteins on T cells that recognize epitopes bound to MHC.

What are the types of T-cells?

Cytotoxic T cells, Helper T cells, and regulatory T-cells

What do cytotoxic T cells do?

Kill infected or abnormal cells.

What do helper T cells do?

Help activate B cells and cytotoxic T cells; include Th1 and Th2 types.

What do regulatory T cells do?

Suppress immune responses to prevent autoimmunity.

What is clonal deletion of T cells?

Process in the thymus that removes self-reactive T cells.

What are the four fates of immature T cells during clonal deletion?

1) T cells that do not recognize body’s MHC protein undergo apoptosis (cell death)

2). T cells that recognize autoantigen die by apoptosis

3)Some “self-recognizing” T cells become regulatory T cells

4)T cells that recognize MHC protein and foreign epitopes become repertoire of protective T cells

Where are B cells primarily found?

In spleen, lymph nodes, and MALT.

What is the function of B cells?

To secrete antibodies.

What is the B cell receptor (BCR)?

Membrane-bound antibody that binds one specific epitope.

How is BCR diversity generated?

By RAG (recombination-activating genes) combines different variable region gene segments to generate antibody diversity

What is an antibody?

A secreted immunoglobulin produced by plasma cells.

What are the functions of antibodies?

Complement activation, neutralization, opsonization, agglutination, and ADCC.

What are the five classes of antibodies?

IgM, IgG, IgA, IgE, IgD.

What is the function of IgM?

First antibody produced.

What is the function of IgG?

Most abundant and long-lasting antibody.

What is the function of IgA?

Associated with body secretions.

What is the function of IgE?

Triggers response to parasites and allergens.

What is the function of IgD?

Function not clearly known.

Where does clonal deletion of B cells occur?

In the bone marrow.

What happens to self-reactive B cells?

They undergo apoptosis or change their BCRs.

What are cytokines?

Soluble proteins that act as signals between immune cells. secreted by leukocytes

What are interleukins (ILs)?

Cytokines that signal among leukocytes.

What are interferons (IFNs)?

Antiviral cytokines.

What are growth factors?

Cytokines that stimulate stem cell division.

What is TNF (tumor necrosis factor)?

Cytokine that kills tumor cells and regulates immune responses.

What are chemokines?

Cytokines that attract leukocytes to infection sites.

What do cell-mediated immune responses target?

Intracellular pathogens and abnormal cells.

What are the steps in cytotoxic T cell activation?

Antigen presentation, helper T cell differentiation, clonal expansion, and self-stimulation.

What are the two killing pathways used by cytotoxic T cells?

Perforin-granzyme pathway and CD95 pathway.

What are memory T cells?

T cells that persist after infection and respond quickly to repeat exposure.

How are cytotoxic T cells regulated?

Require co-stimulation; regulated by APCs and regulatory T cells.

What are antibody immune responses for?

Targeting exogenous antigens and toxins.

What are the steps in T-dependent antibody response?

Antigen presentation to Th cells, Th2 differentiation, B cell activation, B cell proliferation and differentiation.

What are plasma cells?

Short-lived B cells that secrete antibodies specific to the antigen.

What are memory B cells?

Long-lived cells that quickly respond to future encounters with the same antigen.

What is the primary immune response?

Slow, initial production of antibodies.

What is the secondary immune response?

Fast, robust response from memory cells on second exposure.

What are the two ways specific immunity is acquired?

Naturally (daily exposure) and artificially (vaccines).

What are the two types of acquired immunity?

Active (own immune response) and passive (received antibodies).