Lymphoid tissues & transition

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Why do antigens and lymphocytes travel to the lymph nodes?

To avoid being detected by the immune system

To interact with dendritic cells and macrophages for immune response initiation (correct)

To undergo maturation and differentiation processes

To directly destroy pathogens present in the lymph nodes

How do rare specific lymphocytes find their specific antigens?

By passively waiting for antigens to come in contact with them

By randomly migrating through the lymph nodes until they encounter the antigens

By recognizing antigens from a distance using specialized receptors

By following a gradient of chemokines secreted by antigen-presenting cells (correct)

What is the primary function of the peripheral lymphoid tissues?

Filtering of lymph and trapping of antigens (correct)

Production of antibodies

Digestion of pathogens

Maturation of T cells

How do lymphocytes enter the lymph nodes?

Through the HEV Signup and view all the answers

Why is it important for lymphocytes to distinguish between self and non-self molecules?

To prevent autoimmune reactions Signup and view all the answers

Where are antigens taken to allow lymphocytes to locate and react rapidly?

To the lymphoid organs Signup and view all the answers

Which cell type picks up antigens of microbes from epithelia and other tissues and transports them to the lymph nodes?

Dendritic cells (DCs) Signup and view all the answers

Where do lymph nodes concentrate the antigens of microbes entering through epithelia or colonizing tissues?

In draining lymph nodes Signup and view all the answers

Which type of cells can present class I MHC-associated peptides to CD8+ T cells?

All nucleated cells Signup and view all the answers

Where do protein antigens of microbes that live in the cytoplasm of infected cells enter for antigen processing?

Class I MHC pathway Signup and view all the answers

What happens to pathogens once they are ingested by antigen-presenting cells (APCs)?

Processed in the endosome and displayed on MHCII Signup and view all the answers

In the context of antigen presentation, what is required for antigens to be presented on MHCI?

Antigen needs to be in the cytosol Signup and view all the answers

What is the role of classical DCs in the immune response?

Migrating to lymph nodes and presenting antigens to T cells Signup and view all the answers

How are classical DCs activated for migration to lymph nodes?

Chemokines Signup and view all the answers

What is the role of inflammatory cytokines in activating classical DCs?

Causing loss of adhesiveness for epithelia Signup and view all the answers

What directs DCs towards lymph nodes during the immune response?

Chemokines produced by lymphatic endothelium Signup and view all the answers

How do antigens and APCs enter the lymph nodes?

Through afferent lymphatic vessels Signup and view all the answers

Where do B cells primarily go in the lymph nodes?

Follicle (B cell zone) Signup and view all the answers

What is the function of M cells in the mucosal immune system?

Promote the transport of antigens from lumen to underlying tissues Signup and view all the answers

Where are T lymphocytes concentrated in the spleen?

Periarteriolar lymphoid sheaths surrounding small arterioles Signup and view all the answers

What is the role of dendritic cells and macrophages in the spleen?

Capture and concentrate blood-borne antigens Signup and view all the answers

What is the main role of high endothelial venules (HEV) in lymph nodes?

Transport T and B cells into the lymph nodes Signup and view all the answers

Where do most immune cells reside in cutaneous and mucosal immune tissues?

Underneath epithelial barriers Signup and view all the answers

What percentage of the body's lymphocytes are typically found in cutaneous and mucosal tissues?

Approximately 25% Signup and view all the answers

What role do cells in the lamina propria play in mucosal immune tissues?

Provide innate and adaptive immune responses Signup and view all the answers