Chapter 1-6: Immune System and Inflammation - Vocabulary Flashcards

A set of vocabulary flashcards covering key terms, definitions, and roles related to inflammation and innate/adaptive immunity as discussed in the lecture notes.

Inflammation

The body's response to injury or infection; a major driver of chronic disease when persistent or unresolved.

Innate immune system

The non-specific frontline defense present at all times; responds to insults regardless of the pathogen.

Acquired (adaptive) immune system

A specific, memory-based response activated by exposure; vaccines stimulate it for quicker future protection.

Phagocytes

White blood cells that engulf and digest pathogens and debris (phagocytosis).

Macrophages

Frontline phagocytes arriving early to engulf pathogens and damaged cells; secrete mediators like histamine; derive from monocytes and contain enzymes like lysozymes and hydrogen peroxide.

Histamine

A mediator that causes vasodilation and increased endothelial permeability to help immune cells reach tissue.

Lysozymes

Antimicrobial enzymes in macrophages that break down bacterial cell walls.

Hydrogen peroxide

Reactive oxygen species produced by macrophages to kill engulfed pathogens.

Chemotaxis

Movement of immune cells toward a chemical signal indicating damage or infection.

Monocytes

Circulate in blood and differentiate into macrophages in tissue.

Natural killer (NK) cells

Cytotoxic lymphocytes that kill virus-infected or abnormal cells; not primarily phagocytes.

Eosinophils

White blood cells involved in allergies and parasitic infections; elevated in allergic conditions.

Cytokines

Small signaling proteins secreted by immune cells to activate or regulate other immune cells.

TNF-alpha (tumor necrosis factor alpha)

A potent pro-inflammatory cytokine central to the inflammatory response.

Interleukin-1 (IL-1)

Pro-inflammatory cytokine that helps initiate inflammation.

Interleukin-6 (IL-6)

Pro-inflammatory cytokine; elevated levels indicate activation; also produced by muscle during exercise (myokine).

Adipokines

Cytokines secreted by adipose tissue (e.g., TNF-alpha from fat cells) linking obesity to inflammation.

Myokines

Cytokines secreted by muscle (e.g., IL-6 during exercise); can be pro-inflammatory yet contribute to beneficial adaptations.

Arachidonic acid metabolites (eicosanoids)

Pro-inflammatory mediators formed from arachidonic acid (omega-6) into prostanoids and leukotrienes; influenced by omega-3 fats.

Mast cells

Cells that release histamine and other mediators; activated by tissue damage or pathogens and signaling; promote vasodilation and permeability.

Endothelium

The inner lining of blood vessels; regulates permeability and leukocyte exit during inflammation.

Vasodilation

Widening of blood vessels to increase blood flow to injured tissue.

Endothelial permeability

Increased leakiness of the endothelium, allowing fluids and leukocytes to move from blood into tissue.

Neutrophils

First-responding phagocytes that ingest pathogens and release antimicrobial substances.

Adhesion molecules

Molecules that promote leukocyte sticking to endothelium and migration into tissue.

Clotting (vascular phase)

Initial phase that stops bleeding and forms a fibrin mesh to trap debris and pathogens.

Cellular phase

Infiltration of immune cells (neutrophils and macrophages) into tissue to clear pathogens and debris.

Chronic inflammation

Long-lasting inflammation that persists and contributes to disease progression when acute resolution fails.