Chapter 24: The Innate and Adaptive Immune Systems

Organisms that cause infection, such as bacteria, viruses, or fungi.

Intracellular proteins in bacteria that defend against viruses.

General defense actions that can involve any cell type in an organism.

Specific immune reactions that are highly tailored to the particular pathogen that induced them.

A class of white blood cells involved in the immune response.

Lymphocytes that secrete antibodies that bind specifically to pathogens.

Lymphocytes that can directly kill cells infected with pathogens.

The outermost layers of skin and lining of respiratory, digestive, urinary, and reproductive tracts that provide physical and chemical barriers to pathogen invasion.

Receptor proteins that recognize specific repeating patterns called pathogen-associated molecular patterns (PAMPs) on pathogens.

A response triggered by the activation of PRRs, resulting in the production of extracellular signal molecules that mediate inflammation.

Cells that engulf and destroy pathogens, such as macrophages and neutrophils.

Activation of a system of proteins that target pathogens for phagocytosis or lysis.

Lymphocytes responsible for producing antibodies that can bind to specific antigens.

Y-shaped proteins produced by B cells and plasma cells that can bind to specific antigens.

Lymphocytes involved in recognizing specific antigens and coordinating immune responses.

Cell surface molecules that present antigens to T cells for recognition.

It is the first antibody produced during an immune response and is particularly effective at activating the complement system.

It is the most abundant class of antibodies in the bloodstream and is involved in long-term immunity.

It is primarily found in secretions such as saliva, tears, and breast milk, providing localized protection on mucosal surfaces.

It is involved in allergic reactions and defense against parasitic infections.

It is primarily found on the surface of naive B cells, serving as a BCR.

Helper T cells release chemical messengers called cytokines.

Cytotoxic substances released by cytotoxic cells.

It also known as human leukocyte antigens (HLAs) in humans, are cell surface molecules that present antigens to T cells.