Lymphoid Organs and Antigen-Presenting Cells Quiz

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Where are follicular dendritic cells found?

B cell follicles

What is the main function of B cells in an immune response?

Production of antibodies

Which cells engulf microorganisms and present antigens to lymphocytes?

Macrophages

What is the main difference between reticular cells and epithelial reticular cells?

Reticular cells synthesize reticular fibers, while epithelial reticular cells form stroma. Signup and view all the answers

Where are interdigitating dendritic cells found?

Lymph nodes, medulla of thymus, and spleen Signup and view all the answers

Which lymphoid organs do not have reticular cells?

Thymus and cloacal bursa Signup and view all the answers

What are the immunologic attributes possessed by lymphocytes?

Specificity, diversity, memory, and self/non-self recognition Signup and view all the answers

What is the function of primary lymphoid organs?

They provide sites where lymphocytes mature and become antigenically committed. Signup and view all the answers

Why are lymph nodes considered the immune system's first line of defense?

They protect against bacteria or viruses, acting as filters for lymph to remove pathogens before returning it to the bloodstream. Signup and view all the answers

How do secondary lymphoid organs contribute to the immune response?

They capture antigens and provide sites for lymphocytes to become activated by interacting with antigens. Signup and view all the answers

What are the main cellular components found within lymph nodes?

Lymphocytes, macrophages, and dendritic cells Signup and view all the answers

What distinguishes lymph nodes from other lymphatic organs in terms of vessels?

Lymph nodes are the only lymphatic organ with both afferent and efferent lymph vessels and sinuses. Signup and view all the answers

Describe the structure of the red pulp in the spleen.

The red pulp is composed of elongated structures called splenic cords that lie between sinuses. Signup and view all the answers

What are the two main components of the spleen that play a role in blood circulation?

White pulp and red pulp Signup and view all the answers

How does blood leave the spleen?

Blood leaves the spleen through the splenic vein at the hilus. Signup and view all the answers

What distinguishes the white pulp in the spleen from the red pulp?

The white pulp contains central arteries and lymphoid tissue, while the red pulp contains splenic cords and sinuses. Signup and view all the answers

Explain the difference between open and closed blood circulation in the spleen.

Open circulation involves blood percolating through tissue and then collecting into sinuses, while closed circulation involves direct connections between arterioles and venules via sinuses. Signup and view all the answers

What are the main arteries involved in supplying blood to the white pulp of the spleen?

Central arteries Signup and view all the answers

What is the name of the lymphatic tissue distributed throughout the spleen?

White pulp Signup and view all the answers

What cells are proliferating in the pale-staining germinal center of a lymphoid follicle in the spleen?

B cells Signup and view all the answers

What is the identifying characteristic of the central artery found in the white pulp of the spleen?

Lymphocytes aggregated around it in a cylindrical fashion Signup and view all the answers

What fills the spaces in the reticular mesh of lymphatic nodules in the spleen?

B lymphocytes and macrophages Signup and view all the answers

What kind of cells line the venous splenic sinuses?

Extremely long endothelial cells Signup and view all the answers

What is the composition of the red pulp in the spleen?

Smooth muscle cells or myofibroblasts Signup and view all the answers

What is the structure of a lymph node?

Lymph nodes are surrounded by a capsule composed primarily of dense irregular connective tissue. Signup and view all the answers

What are trabeculae in a lymph node responsible for?

Trabeculae provide support for the entire node, carry blood vessels and nerves, and are surrounded by sinuses. Signup and view all the answers

Describe the composition of the stroma of a lymph node.

The stroma is composed of reticular cells and fibers that support lymphocytes, macrophages, and plasma cells. Signup and view all the answers

What cell types are found in the outer cortex layer of a lymph node?

The outer cortex layer contains lymphocytes (mostly B cells), macrophages, and follicular dendritic cells. Signup and view all the answers

What happens to primary follicles in the lymph node after an antigenic challenge?

After antigenic challenge, the primary follicles enlarge into secondary follicles, each containing a germinal center. Signup and view all the answers

What is the inner cortex (paracortex) of a lymph node?

The inner cortex is the region between the outer cortex and the medulla that is free of nodules. Signup and view all the answers