BIOL 117 Module 18

Flashcards covering key concepts related to innate and adaptive immunity, immune responses, and associated disorders.

Innate immunity provides a rapid, __ response to broad classes of pathogens.

generic

The genes that encode T-cell and B-cell receptor proteins are generated through __.

gene recombination

T cells are activated when their receptors recognize epitopes displayed in __ proteins.

MHC

B cells differentiate into __ cells and memory cells when fully activated by helper T cells.

plasma

The immune system rejects blood transfusions and tissue transplants based on the presence of __ molecules.

nonself

Memory lymphocytes produced during a primary infection allow the immune system to respond __ to future infections.

rapidly

Allergies are abnormal immune responses to antigens called __.

allergens

Autoimmune diseases occur when lymphocytes initiate an immune response against the body’s own __.

tissues

Immunodeficiency diseases can arise from genetic mutations or __ infections that disrupt the immune system.

viral

The clonal selection theory explains how the most appropriate cells for controlling an infection are __ and replicated.

selected

What is the main function of innate immunity?

To provide a rapid, generic response to broad classes of pathogens by recognizing pathogen-associated molecules.

How do animals initially prevent infection?

By establishing barriers that prevent the entry of pathogens.

What role do pattern-recognition receptors play in innate immunity?

They recognize pathogen-associated molecules to trigger the innate immune response.

What occurs during the inflammatory response?

White blood cells endocytose foreign material and release cytokines to recruit more phagocytic cells.

Which cells are central to the vertebrate adaptive immune response?

T cells and B cells.

How do T cells and B cells recognize specific antigens?

Through unique receptors on their surfaces that bind to specific epitopes.

What process generates the diversity of T-cell and B-cell receptors?

Gene recombination (rearrangement of gene segments).

Why can the adaptive immune system respond to so many different antigens?

Each receptor formed through gene recombination is slightly different, creating vast diversity.

What does the clonal selection theory explain?

How the most appropriate immune cells are selected and replicated to control infection.

How are T cells activated?

When their receptors recognize epitopes presented on MHC proteins of antigen-presenting cells, along with secondary signals from cytokines.

How are B cells activated?

By binding free antigens with their receptors, and often require helper T cell activation for full differentiation.

Into what do activated B cells typically differentiate?

Plasma cells and memory cells.

How are extracellular pathogens eliminated?

Through phagocytosis and substances secreted in the humoral response, including antibodies.

Name three ways antibodies help eliminate pathogens.

Opsonizing, neutralizing, and agglutinating pathogens, or co-stimulating complement proteins.

How are intracellular pathogens eliminated?

Through the cell-mediated response by cytotoxic T cells inducing apoptosis of infected host cells.

Why does the immune system reject blood transfusions or tissue transplants?

Due to the presence of nonself molecules (cell-surface glycoproteins or MHC proteins) or absence of self molecules.

What enables a faster immune response during future infections by the same pathogen?

Memory lymphocytes produced during a primary infection or vaccination.

What are allergies?

Abnormal immune responses to harmless antigens called allergens.

What happens in autoimmune diseases?

Lymphocytes mistakenly initiate an immune response against the body's own tissues.

What are immunodeficiency diseases? Give examples.

Diseases resulting from mutations or infections that disrupt immune system function (e.g., SCID, AIDS).