Immunoglobulin Functions Quiz

What is the primary reason for the adaptive immune subsystem being the most important layer of defense?

Its ability to generate resistance proportional to the threat

Which type of immunity is directed against extracellular invaders?

Antibody (humoral) immunity

What is the function of regulatory cells and cytokines in the immune system?

To ensure that adaptive immune responses occur only under appropriate circumstances

What must occur sequentially for an antibody-mediated or cell-mediated immune response to occur?

The capture and processing of foreign antigens, followed by recognition by lymphocytes Signup and view all the answers

What is the role of regulatory T cells (Treg cells)?

Inhibit conventional immune responses and prevent the development of autoimmunity Signup and view all the answers

How do immune cells communicate with each other?

Through physical contact and exchange of signals through receptors Signup and view all the answers

What is the primary function of cytokines in immune cell signaling?

Promoting the synthesis of specific proteins in the target cell Signup and view all the answers

What is the role of interferons in immune cell interactions?

Have substantial antiviral activity Signup and view all the answers

How do T cells protect animals against intracellular invaders?

By mounting a cell-mediated response Signup and view all the answers

What makes it difficult to predict how a specific target cell will respond to cytokines?

The complex mixtures of hundreds of different cytokines acting together Signup and view all the answers

Which type of dendritic cell triggers antibody formation?

DC2 cells Signup and view all the answers

What type of immune response is promoted by Th1 cells?

Cell-mediated immunity Signup and view all the answers

Which cytokine is secreted by Th2 cells?

IL-4 Signup and view all the answers

What is the role of cytotoxic T cells in combating viral infections?

Killing virus-infected cells Signup and view all the answers

Which protein do cytotoxic T cells express on their surface?

CD8 Signup and view all the answers

What is the function of costimulation from a helper T cell for cytotoxic T cells?

Enabling their function Signup and view all the answers

Which type of cell does IFN-gamma from Th1 cells activate to destroy intracellular bacteria?

M1 macrophages Signup and view all the answers

What does the adaptive immunity rely on for enhanced and accelerated response against invading microbes?

Recognition of previously encountered microbes Signup and view all the answers

What is the role of memory T cells in immunologic memory?

Mounting enhanced immune responses Signup and view all the answers

Why do most cytotoxic T cells die once they are no longer needed?

Lack of costimulation from helper T cells Signup and view all the answers

What is the main reason for immunologic memory resulting from adaptive immunity?

Recognition of previously encountered microbes Signup and view all the answers

What is the role of antibodies in the immune system?

They bind to foreign molecules and mark them for destruction by phagocytic cells Signup and view all the answers

Where are memory B cells located within an animal?

They can persist within an animal for many years Signup and view all the answers

What is the role of T helper type 2 cells in the immune system?

Provide assistance to B cells for antibody production Signup and view all the answers

Where are B cells and plasma cells located within the body?

Within lymphoid organs Signup and view all the answers

Which class of immunoglobulin is usually confined to the bloodstream?

IgM Signup and view all the answers

What triggers B cells to respond by mounting immune responses?

Foreign antigens Signup and view all the answers

What is the main role of plasma cells?

Synthesize and secrete enormous quantities of antibodies Signup and view all the answers

Where do B cells originate?

Bone marrow Signup and view all the answers

What happens when an animal encounters an antigen for the second time?

The memory B cells respond rapidly Signup and view all the answers

What must happen for a B cell to respond to a bound foreign antigen?

It must also receive costimulation from helper T cells Signup and view all the answers

What is the role of IgG in the defense of the body?

Eliminating organisms that succeed in penetrating deep into the body Signup and view all the answers

What is the function of IgE?

To control invasion by parasites and mediate acute inflammation in allergic states Signup and view all the answers

Where are Langerhans cells primarily found?

Dermis Signup and view all the answers

What is the role of MHC molecules?

To determine whether an individual can respond to a foreign antigen Signup and view all the answers

Why do surviving T cells respond only to foreign antigens?

Because normal body component receptors on T cells are killed during maturation in the thymus Signup and view all the answers

What is the main function of dendritic cells?

To capture, process, and present foreign antigens to helper T cells Signup and view all the answers

What is the primary function of IgA on body surfaces?

To complement the physical barriers of the body and block microbial invasion Signup and view all the answers

What is the significance of receptor molecules called MHC molecules on dendritic cells?

They carry antigen-receptor complexes to the dendritic cell surface Signup and view all the answers

How are antibody responses regulated?

By binding antigen fragments presented by dendritic cells Signup and view all the answers

What is the role of IgD in the immune response?

To play a role in the response to the normal microbiota Signup and view all the answers

What happens if an animal lacks MHC molecules that can bind a specific antigen?

It will be unable to respond to that specific antigen. Signup and view all the answers

What is the characteristic of MHC molecules expressed within an individual animal?

They can bind many, perhaps most, foreign antigens. Signup and view all the answers

What happens when a dendritic cell presents MHC-associated antigen to T cells?

All T cells with appropriate receptors will bind to the dendritic cell. Signup and view all the answers