ap bio - the immune system

Innate Immunity

Immunity present at birth that provides immediate, nonspecific defense against pathogens.

Pathogens

Microorganisms that can cause disease, such as bacteria and viruses.

Phagocytosis

The process by which certain white blood cells engulf and digest pathogens.

Antimicrobial Peptides

Small proteins that can directly attack microbes and impede their reproduction.

Inflammatory Response

A crucial response to injury or infection involving histamine release, swelling, and immune cell recruitment.

Natural Killer Cells

A type of lymphocyte that destroys cancerous or infected cells lacking the proper MHC protein.

Active Immunity

Immunity that develops in response to an infection or vaccination.

Passive Immunity

Short-term immunity conferred by antibodies from another individual.

Histamine

A chemical released by mast cells during an inflammatory response to promote leaky blood vessels.

Allergens

Substances that cause exaggerated immune responses known as allergies.

MHC Molecules

Major histocompatibility complex proteins that help the immune system recognize cells as self or non-self.

Antigen

Any foreign molecule that elicits an immune response.

Lymphocytes

White blood cells, including T cells and B cells, involved in the immune response.

Anaphylactic Shock

A severe and potentially life-threatening allergic reaction that can occur after exposure to an allergen.

Pus

Thick fluid composed of dead white blood cells, bacteria, and tissue debris at the site of inflammation.

Complement System

A set of proteins that work to lyse invading cells and trigger inflammation.

Antibodies

Proteins produced by B cells that specifically recognize and bind to antigens.

Immunosuppressive Drugs

Medications that suppress the immune response to facilitate organ transplantation.

Epitopes

Specific parts of an antigen that are recognized and bound by antibodies or antigen receptors.

Fever

A systemic response to infection characterized by elevated body temperature.

Tuberculosis

A pathogen primarily affecting the lungs but can spread to other organs. It avoids the host immune response by surviving and multiplying within macrophages and preventing phagosome-lysosome fusion.