Immune System Main Points

These flashcards cover key vocabulary and concepts related to the immune system from Chapter 21, focusing on innate and adaptive defenses.

Surface barriers

First line of defense; includes skin and mucous membranes.

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

Tissue response to injury that prevents the spread of harmful agents and promotes healing.

Cardinal signs of inflammation

Swelling, redness, heat, pain; results from inflammatory chemicals.

Interferons

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

Complement system

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

Fever

A systemic response to infection that aids in fighting pathogens.

Adaptive immune system

Recognizes foreign substances and involves B and T lymphocytes to provide a specific response.

Antigens

Substances that trigger the adaptive immune response.

Complete antigens

Antigens with both immunogenicity and reactivity.

Haptens

Incomplete antigens that require a combination with body proteins to become immunogenic.

Antigenic determinants

Portions of antigen molecules recognized as foreign.

Major histocompatibility complex (MHC)

Membrane-bound glycoproteins that mark our cells as self.

Lymphocytes

White blood cells that arise from hematopoietic stem cells and develop immunity.

Immunocompetence

The ability of lymphocytes to recognize and respond to specific antigens.

Clonal selection

The process where naive lymphocytes encounter their antigen and proliferate.

Memory cells

Lymphocytes capable of mounting a rapid response to a previously encountered antigen.

Antigen-Presenting Cells (APCs)

Cells that internalize antigens and present them for recognition by T cells.

B cells

Lymphocytes that provide humoral immunity and secrete antibodies.

Plasma cells

Effector B cells that secrete antibodies.

Immunological Memory

The ability to mount a faster attack against the same antigen upon re-exposure.

Active humoral immunity

Immunity acquired through infection or vaccination that provides lasting protection.

Passive immunity

Immunity gained by the transfer of antibodies, providing short-term protection.

Antibody monomer

Structure consisting of four polypeptide chains (two heavy, two light) that recognize specific antigens.

Classes of antibodies

Five types: IgM, IgA, IgD, IgG, and IgE, differing in structure and function.

Monoclonal antibodies

Pure preparations of a single type of antibody, used in diagnostics and cancer treatment.

Cellular immunity

Immune response directed by T lymphocytes that target infected or cancerous cells.

MHC Class I proteins

MHC proteins found on all nucleated cells, presenting antigens to CD8 T cells.

MHC Class II proteins

MHC proteins found only on APCs, presenting antigens to CD4 T cells.

Effector T cells

Activated T cells that mount the immune response against pathogens.

Helper T cells

T cells that activate B cells and other T cells; essential for immune response.

Cytotoxic T cells

T cells that directly attack and kill infected or cancerous cells.

Regulatory T cells (TReg)

T cells that maintain tolerance and prevent autoimmune responses.

Immunodeficiency diseases

Diseases like AIDS or SCID where the immune system fails to function properly.

Autoimmune disease

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

Hypersensitivity

Abnormally intense reactions to harmless antigens, such as allergies.

Immediate hypersensitivity

Rapid allergic reactions mediated by IgE antibodies.

Delayed hypersensitivity

A type of immune response that takes longer to develop, associated with T cells.

Developmental Aspects of the Immune System

The progression of immune system functionality from fetal development to aging.

Aging and the immune system

Older adults experience decreased immune responsiveness and increased susceptibility to diseases.