Immune System Main Points

These flashcards cover key concepts related to innate and adaptive immune defenses, including definitions of important terms and mechanisms of the immune system.

Innate Defenses

The body's primary defenses against pathogens, including surface barriers and internal defenses.

Surface Barriers

Mechanical barriers such as skin and mucous membranes that prevent pathogen entry.

Phagocytes

Cells like macrophages and neutrophils that engulf and destroy pathogens.

Natural Killer (NK) Cells

Large granular lymphocytes that kill virus-infected and cancerous cells.

Inflammatory Response

The body's response to injury that prevents the spread of harmful agents and promotes healing.

Cardinal Signs of Inflammation

Swelling, redness, heat, and pain resulting from inflammatory chemicals.

Exudate

Fluid that leaks into tissues during inflammation, containing leukocytes and nutrients.

Interferons

Proteins synthesized by virus-infected cells that prevent viruses from multiplying.

Complement Activation

A group of plasma proteins that enhance inflammation and promote phagocytosis.

Fever

An elevated body temperature that enhances the body's fight against pathogens.

Adaptive Immune System

Recognizes foreign substances and acts to immobilize, neutralize, or remove them.

Antigens

Substances that trigger the body's adaptive immune response.

Immunogenicity

The ability of an antigen to provoke an immune response.

Haptens

Incomplete antigens that require a body protein to become immunogenic.

Antigenic Determinants

Specific parts of an antigen that are recognized by the immune system.

Major Histocompatibility Complex (MHC)

Membrane proteins that identify self-cells to the immune system.

T Lymphocytes

Cells that provide cellular immunity and develop in the thymus.

B Lymphocytes

Cells that provide humoral immunity and develop in the bone marrow.

Immunocompetence

The ability of lymphocytes to recognize specific antigens.

Clonal Selection

The process by which lymphocytes proliferate and differentiate upon encountering their antigen.

Memory Cells

Long-lived cells that respond rapidly upon re-exposure to the same antigen.

Antigen-Presenting Cells (APCs)

Cells that present antigenic determinants to T cells for recognition.

Plasma Cells

Effector B cells that secrete antibodies during the primary immune response.

Humoral Immunity

The aspect of immunity that involves antibodies targeting extracellular antigens.

Active Humoral Immunity

Immunity gained through infection or vaccination with immunological memory.

Passive Humoral Immunity

Immunity acquired by receiving antibodies from another individual.

Antibody Monomer

A basic unit of an antibody consisting of four polypeptide chains.

Five Classes of Antibodies

IgM, IgA, IgD, IgG, and IgE, each with distinct structures and functions.

Monoclonal Antibodies

Purified antibodies produced from a single clone of immune cells, useful in diagnostics.

Cellular Immunity

The immune response involving T lymphocytes that directly attack infected or abnormal cells.

Cytokines

Proteins that mediate and regulate immunity and inflammation, released by immune cells.

Helper T Cells

T cells that activate B cells, macrophages, and other T cells by releasing cytokines.

Cytotoxic T Cells

T cells that directly kill infected cells and cancer cells.

Regulatory T Cells (TReg)

Cells that maintain tolerance and prevent excessive immune responses.

Immunodeficiency Diseases

Conditions where the immune system has a reduced ability to fight infections.

Autoimmune Diseases

Diseases where the immune system attacks the body's own tissues.

Hypersensitivity

An exaggerated immune response to a normally harmless antigen.

Developmental Aspects of the Immune System

Changes in the immune system's function and responsiveness throughout a person's life.