The Immune System: Components and Lymphocytes

Which organ completes B cell development after they are formed in bone marrow?

• Tonsils

• Thymus

• Adenoids

• Spleen

Which item is a valid example of an antigen listed in the material?

• Digestive enzymes produced by the pancreas

• Pollen entering the respiratory tract

• Compatible red blood cell surface proteins

• Neutralized antibodies circulating in plasma

What happens immediately after lymphocytes recognize a specific antigen?

• They generalize and attack all body tissues

• They inhibit receptors to avoid any response

• They bind and initiate a targeted attack

• They detach and form nonspecific memory

A patient has influenza. Which explanation best describes how the body tailors its immune response?

• Receptors attach to any antigen regardless of type

• The body releases lymphocytes with matching receptors

• Receptors change to fit every new foreign molecule

• All lymphocytes bind to flu antigens equally well

Which event initiates the cell-mediated immune response shown in the diagram?

• Cytotoxic T cells lyse infected host cells

• Macrophage engulfs pathogen and displays antigens

• Interleukin-1 activates naïve helper T cells

• Helper T cells release interleukin-2 cytokines

Which statement best describes the role of interleukin-2 in this response?

• Marks infected body cells for antibody-mediated destruction

• Activates macrophage phagocytosis of free pathogens

• Directly causes lysis of pathogens in extracellular fluid

• Stimulates division of helper T cells and cytotoxic T production

A patient lacks functional helper T cell receptors. Based on the diagrammed pathway, which outcome is most likely?

• Interleukin-1 release will occur at higher levels

• Cytotoxic T cells will be produced in insufficient numbers

• Macrophages will fail to engulf and process pathogens

• Infected cells will be destroyed more rapidly than normal

Which event directly triggers B cell activation in the humoral immune response?

• Secretion of antibodies into the bloodstream

• Binding of antigen to memory cells

• Phagocytosis by plasma cells

• Release of IL-2 from helper T cells

Place the following steps in the correct order for the humoral response: activation of B cells, formation of plasma cells, secretion of antibodies, generation of memory cells.

• Memory cells → activation → antibodies → plasma cells

• Activation → antibodies → plasma cells → memory cells

• Antibodies → activation → memory cells → plasma cells

• Activation → plasma cells → antibodies → memory cells

Which statement best explains how antibodies aid in pathogen elimination?

• They convert antigens into helper T cells

• They digest antigens through cellular respiration

• They bind antigens and mark them for destruction

• They enter cells and replicate the antigen