Junquiera 14 Immune System and Lymphoid Organs

This set of flashcards contains key vocabulary terms and definitions related to the immune system and lymphoid organs, aimed at aiding in studying the material effectively.

Innate immunity

Nonspecific defense mechanisms present from birth.

Adaptive immunity

Specific immune response developed in response to exposure to pathogens.

Memory cells

Long-lived immune cells that allow for rapid response upon re-exposure to an antigen.

Lymphatic system

Network of vessels that transport lymph back to the bloodstream.

Primary lymphoid organs

Sites where lymphocytes are formed; includes thymus and bone marrow.

Secondary lymphoid organs

Tissues where lymphocyte activation and proliferation occur; includes spleen and lymph nodes.

Mucosa-associated lymphoid tissue (MALT)

Lymphoid tissue found in mucosal membranes throughout the body.

Granulocytes

Type of leukocyte involved in innate immunity, such as neutrophils and eosinophils.

Natural killer (NK) cells

Leukocytes that destroy infected or cancerous cells.

Toll-like receptors (TLRs)

Receptors on leukocytes that recognize pathogenic components.

Cytokines

Signaling proteins that mediate and regulate immunity, inflammation, and hematopoiesis.

Interferons

Cytokines that help the body fight off viral infections.

Complement system

Proteins that enhance the immune response through opsonization and lysis of pathogens.

Defensins

Antimicrobial peptides that disrupt microbial cell membranes.

Lysozyme

An enzyme that breaks down bacterial cell walls.

Spleen

An organ filtering blood and housing lymphocytes.

Thymus

Primary lymphoid organ where T-lymphocytes mature.

Lymph nodes

Secondary lymphoid organs that filter lymph and site of immune activation.

T lymphocytes

Type of lymphocyte that plays a central role in cell-mediated immunity.

B lymphocytes

Type of lymphocyte responsible for producing antibodies.

Plasma cells

Activated B cells that secrete antibodies.

Hassall's corpuscles

Structures in the thymus medulla involved in T cell development.

Antigen presenting cells (APCs)

Cells that display antigens to T lymphocytes; includes dendritic cells.

High endothelial venules (HEVs)

Specialized blood vessels that facilitate lymphocyte entry into lymph nodes.

Immunoglobulin

Antibodies produced by B cells.

Germinal center

Site in lymphoid follicles where B cell proliferation and differentiation occur.

Peyer patches

Clusters of lymphoid tissue in the ileum that monitor intestinal bacteria.

Tonsils

Lymphoid tissues that protect against pathogens entering via the mouth and nose.

Adaptive response

Immune response tailored to specific pathogens with memory formation.

Chemotaxis

The movement of cells toward the site of infection or inflammation.

Phagocytosis

The process by which cells engulf and digest pathogens.

Opsonization

The coating of pathogens to enhance their recognition and ingestion by phagocytes.

Cytotoxic T lymphocytes (CTLs)

T cells that kill infected or cancerous cells by releasing perforin and granzymes.

Regulatory T cells

T cells that control and moderate immune responses.

B cell receptor (BCR)

Membrane-bound immunoglobulin on B cells that recognizes antigens.

Variable region

Part of an antibody that binds to specific antigens.

Central tolerance

The elimination of T cells that react to self-antigens in the thymus.

Peripheral tolerance

Mechanisms that prevent autoimmunity outside of the thymus.

Cytokine storm

An overproduction of cytokines leading to severe inflammation.

Bone marrow

Primary lymphoid organ where B cells develop.

Filtration

The process by which lymph nodes remove pathogens from lymph.

Lymphatic vessels

Channels that transport lymph back to the bloodstream.

Medullary sinus

Lymph-filled spaces in lymph nodes.

Splenic cord

Structures in the spleen that contain blood cells and macrophages.

Erythropoiesis

The process of producing red blood cells.

Thymic involution

The shrinkage of the thymus with age.

Lymphadenopathy

Disease condition characterized by swollen lymph nodes.

Lymphocyte recirculation

The process by which lymphocytes move between blood and lymphatic systems.

Invariant NK T (iNKT) cells

A unique subset of T cells that recognize lipid antigens.

Hybridoma

A cell line that produces large amounts of a specific antibody.

Immunization

The process of inducing immunity through exposure to antigens.

Anaphylaxis

Severe allergic reaction that is rapid and can be life-threatening.

Monocytes

Type of leukocyte that differentiates into macrophages and dendritic cells.

T lymphoblasts

Immature T cells that undergo differentiation in the thymus.

Reticular fibers

Type of connective tissue that provides a supportive framework in lymphoid organs.

B cell activation

Process where B cells proliferate and differentiate into plasma cells upon antigen encounter.

Antigenic determinant

Specific part of the antigen recognized by antibodies or immune cells.

Immunotherapy

Treatment that harnesses the immune system to fight diseases, especially cancer.

Cytokines

Cell signaling molecules that mediate inflammation and immune responses.

Monoclonal antibodies

Antibodies produced by identical immune cells that are clones of a unique parent cell.

Pathogen-associated molecular patterns (PAMPs)

Molecules associated with groups of pathogens recognized by the immune system.

Immunoglobulin G (IgG)

The most common type of antibody found in blood.

Immunoglobulin A (IgA)

Antibody found in mucosal areas such as the gut, respiratory tract, and urogenital tract.

Immunoglobulin M (IgM)

The first antibody produced during an immune response.

Immunoglobulin E (IgE)

Antibody that plays a crucial role in allergic reactions.

Immunoglobulin D (IgD)

Antibody found on the surface of B cells.

Agglutination

The clumping of particles, such as bacteria, due to the binding of antibodies.

T helper cell

The type of T cell that helps activate B cells and other T cells.

Perforin

A protein that forms pores in the membranes of infected cells.

Granzymes

Enzymes released by cytotoxic T cells that induce apoptosis in target cells.

Degranulation

The release of cytotoxic granules from mast cells and basophils during an allergic response.

Histamine

Chemical released during allergic reactions that increases blood vessel permeability.

Feeding tolerance

A state of immunological unresponsiveness to antigens from food.

M cells

Specialized epithelial cells in the gut associated with the immune response.

Dendritic cells

Antigen-presenting cells that activate T cells.

B la cells

Another term for B cells that have only matured and are ready to respond to antigens.

Myeloid lineage

The lineage of blood cells that includes monocytes and granulocytes.

Metastatic cancer

Cancer that has spread from the original site to other parts of the body.

Lymphokines

Cytokines produced by lymphocytes that mediate the immune response.

Complement activation

The process by which the complement system enhances the ability of antibodies to clear pathogens.

Immunogenicity

The ability of an antigen to provoke an immune response.

T cell receptor (TCR)

The receptor on T cells that recognizes antigens presented by MHC.

Chimeric antigen receptors (CAR)

Synthetic receptors that give T cells enhanced specificity for tumor antigens.

B cell clone

A group of B cells derived from a single ancestor that produces the same antibody.

IgG subclass

Different forms of IgG that have varied roles in immune response.

Diversity of antibodies

The wide variety of specificities that antibodies can have due to genetic rearrangements.

Immunologic memory

The capacity of the immune system to remember previous encounters with pathogens.

Tumor necrosis factor (TNF)

A cytokine involved in systemic inflammation.

Interleukin-2 (IL-2)

A cytokine that promotes the growth and activity of T cells.

Leukocyte adhesion defects

Genetic conditions that affect the ability of white blood cells to migrate to inflammatory sites.

Transfusion therapy

The process of transferring blood or blood components into a patient.

Steroid therapy

The use of steroid medications to reduce inflammation and suppress the immune system.

Genetic engineering in vaccines

Using genetic methods to produce vaccines that elicit an immune response.

Monoclonal antibody therapy

Use of monoclonal antibodies for treatment, particularly in cancer and autoimmune diseases.

Immuno-oncology

A field that uses the body's immune system to fight cancer.

Bronchus-associated lymphoid tissue (BALT)

Lymphoid tissue located in the walls of the bronchi, providing immune surveillance of the respiratory tract.

Gut-associated lymphoid tissue (GALT)

Collective term for all lymphoid tissues in the gastrointestinal tract, including Peyer patches.

Nasopharynx-associated lymphoid tissue (NALT)

Lymphoid tissue found in the nasopharynx, involved in immune responses to airborne pathogens.

Interleukin-1 (IL-1)

A major pro-inflammatory cytokine that initiates and amplifies inflammatory responses, stimulates the expression of adhesion molecules, and induces fever by acting on the hypothalamus.

Interleukin-6 (IL-6)

A cytokine involved in acute phase reactions, stimulating the liver to produce acute-phase proteins like C-reactive protein, and promotes B cell differentiation into antibody-secreting plasma cells, playing a role in both innate and adaptive immunity.