Immune Response: Module 3, Lesson 1, Part 1

Flashcards covering key vocabulary related to the body's defenses, inflammatory response, and immune system components based on Module 3, Lesson 1, Part 1 lecture notes.

Innate Immunity

The body's natural, non-specific defenses that provide immediate protection against pathogens.

Adaptive Immunity

Specific immune responses developed after exposure to a pathogen, providing tailored and memory-based protection.

Barrier Defenses

Physical and chemical mechanisms that prevent harmful substances from entering the body, such as skin, mucous membranes, and gastric acid.

Skin

A primary barrier defense that protects internal tissues and organs.

Mucous Membranes

Linings in areas exposed to external influences that lack skin protection, contributing to barrier defenses.

Gastric Acid

Acid secreted by the stomach that neutralizes pathogens as part of barrier defenses.

Major Histocompatibility Complex (MHC)

A group of genes responsible for proteins that distinguish between self-cells and foreign cells.

Inflammatory Response

A localized protective tissue response to injury or infection characterized by increased capillary permeability, erythema, heat, edema, and pain.

Increased Capillary Permeability

A key change during inflammation that allows leukocytes, antibodies, complement, and clotting factors to enter injured tissue.

Erythema

Redness caused by increased blood flow due to vasodilation during inflammation.

Edema

Swelling caused by fluid leaking into tissues during inflammation.

Extravasation

The process by which leukocytes exit blood vessels and enter inflamed tissue, also known as margination and emigration.

Chemokines

Chemicals (chemoattractants) that attract leukocytes, such as macrophages and neutrophils, to the site of inflammation; the process is called chemotaxis.

Cytokines

Proteins that promote the activation, proliferation, and differentiation of immune cells, including interleukins, TNF, interferons, and colon-stimulating factors.

Leukocytes

White Blood Cells, which are crucial components of the immune system.

Hematopoietic Stem Cell

Pluripotent bone marrow cell that is the common ancestor for all blood cells, including leukocytes.

Common Lymphoid Progenitor

Stem cell that differentiates into B cells, T cells, and Natural Killer Cells.

Common Myeloid Progenitor

Stem cell that differentiates into erythrocytes, macrophages, granulocytes, and dendritic cells.

Granulocytes

Leukocytes named for their cytoplasmic granules, including neutrophils, basophils, and eosinophils.

Neutrophils

Short-lived, phagocytic granulocytes that primarily attack bacterial invaders.

Neutropenia

A condition characterized by a low count of neutrophils.

Basophils

Granulocytes involved in histamine-type reactions.

Eosinophils

Granulocytes primarily involved in allergic reactions and defense against parasites and fungus.

Monocyte

A type of leukocyte that differentiates into macrophages and dendritic cells.

Macrophage

Phagocytic cells found in tissues that present antigens, release cytokines/chemokines, and are involved in chronic inflammatory responses; known by different names in various tissues (e.g., Kupfer cells in liver).

Kupfer Cells

Macrophages found in the liver.

Microglial Cells

Macrophages found in the nervous system.

Langerhans Cells

Macrophages found in the skin.

Histocytes

Macrophages found in connective tissue.

Antigen Presenting Cell (APC)

A cell that displays antigen fragments on its surface to activate T cells, such as macrophages and dendritic cells.

Granuloma

A collection of macrophages formed as a chronic immune response to persistent irritation, often featuring multinucleated giant cells.

Dendritic Cell

Phagocytic and macropinocytic cells that recognize pathogen features and are potent antigen-presenting cells.

Mast Cell

Cells found in most exposed tissues (skin, lungs, GI tract) that activate the inflammatory response by releasing chemokines and cytokines from their granules, increasing membrane permeability and leukocyte chemotaxis.

Histamine

A chemical released by mast cells that activates the inflammatory response, increasing membrane permeability.

Lymphocytes

Immune cells (B cells, T cells, Natural Killer cells) that control and direct inflammation, destroy invaders, and prepare for tissue repair.

B Lymphocyte (B Cell)

Lymphocytes that mature in the bone marrow and, upon activation, differentiate into plasma cells to produce antibodies.

Plasma Cell

Differentiated B lymphocytes that are specialized to produce and secrete large quantities of antibodies.

Antibodies

Proteins produced by plasma cells that neutralize pathogens, facilitate opsonization, and activate the complement system.

T Lymphocytes (T Cells)

Lymphocytes that mature in the thymus and mediate cell-mediated immunity, including cytotoxic T cells and helper T cells.

CD8 Cells (Cytotoxic T Cells)

T lymphocytes that directly kill viral-infected or otherwise damaged cells by recognizing antigens presented via MHC I.

CD4 Cells (Helper T Cells)

T lymphocytes that direct B lymphocytes and macrophages, playing a central role in coordinating the immune response by recognizing antigens presented via MHC II.

Apoptosis

Programmed cell death, which most activated lymphocytes undergo once a threat is neutralized.

Memory Cells

A few activated lymphocytes that persist after an infection, providing long-term immunity and a faster response to subsequent exposure.

Thymus

The primary lymphoid organ where T lymphocytes mature and differentiate.

Neutralization (Antibody function)

The mechanism by which antibodies prevent pathogens from entering cells by binding to their antigens.

Opsonization (Antibody function)

The process by which antibodies or complement proteins coat pathogens, making them more easily recognized and engulfed by phagocytic cells like macrophages.

Complement System

A cascade of proteins that can be activated by antigen-antibody complexes, leading to the destruction of pathogens.