Inflammation and Innate Immune Response – Video Notes

Question-and-answer flashcards covering definitions, mechanisms, mediators, cellular players, and outcomes of inflammation and innate immunity.

What is inflammation?

Protective vascular and cellular response to tissue injury that minimizes damage, removes damaged tissue, prevents spread, and prepares for healing.

What does the suffix '-itis' indicate in medical terms?

Inflammation (as in pancreatitis, appendicitis, colitis, diverticulitis).

What is innate immunity?

Non-specific, native defense that is rapid and present at birth; serves as the first line of defense.

What are the two major branches of the immune response?

Innate immunity and adaptive immunity.

What are the components of adaptive immunity?

Humoral immunity (B-lymphocytes/antibodies) and cell-mediated immunity (T-lymphocytes).

What are the main effector cells in the inflammatory response?

Granulocytes and macrophages (phagocytes).

What is acute inflammation?

A rapid reaction to injury lasting hours to days, with vascular and cellular stages, aiming to heal; can resolve or progress.

What occurs in the vascular stage of acute inflammation?

Vasodilation and increased vascular permeability, leading to increased blood flow and exudation.

What occurs in the cellular stage of acute inflammation?

Leukocyte activation, migration to the injury site, phagocytosis; chemotaxis and leukocytosis.

What triggers the inflammatory response?

Pathogens or tissue injury that release inflammatory mediators and activate innate immune defenses.

Name key inflammatory mediators and their effects.

Bradykinin—vasodilation; Histamine—vasodilation and increased permeability; Prostaglandins—vasodilation, pain, fever; Leukotrienes—increased permeability and leukocytosis; Cytokines—pro-inflammatory, promotes leukocytosis.

What is exudate?

Mass of cells and fluid that seeps out of inflamed vessels to transport protective cells and debris; supports healing.

What are the types of exudate?

Transudate/Serous (watery, mostly protein), Purulent (pus with degraded WBCs/tissue debris), Effusion (exudate in a body cavity).

Which cells are granulocytes?

Neutrophils, eosinophils, basophils.

What are phagocytes and which cells perform phagocytosis?

Monocytes/macrophages (and neutrophils) perform phagocytosis; monocytes mature into macrophages and secrete cytokines.

What is leukocytosis and its normal range?

Elevated white blood cell count; normal range ~4,000–10,000 cells/mL; leukocytosis often 15,000–20,000+ cells/mL.

How does acute vs. chronic inflammation differ in cellular infiltrates?

Acute inflammation is neutrophil-predominant; chronic inflammation features monocytes/macrophages and lymphocytes.

What is chronic inflammation?

Recurrent, prolonged inflammatory response (>2 weeks) where the cause is not eliminated; macrophages and lymphocytes predominate; granulomas may form.

What is a granuloma?

A mass of white blood cells, mostly macrophages, formed during chronic inflammation.

What are common outcomes of acute inflammation?

Resolution/healing; fibrosis/scar formation; abscess formation; non-resolution with persistent trigger leading to chronic inflammation.

What signs characterize acute vascular inflammation?

Redness, swelling, heat, pain, and impaired function; histamine is a dominant mediator.

What signs characterize acute cellular inflammation?

Leukocytosis; systemic symptoms like pain, fever, fatigue; lymphadenopathy may occur.

What is fever and how is it produced?

Elevation in body temperature caused by pyrogens; hypothalamus raises the set point, leading to chills and later fever; resolves when trigger ends.

What is Systemic Inflammatory Response Syndrome (SIRS)?

Overwhelming systemic inflammation affecting multiple organs; cytokine storm; can cause organ failure; may lead to sepsis if infection is present.

What is sepsis and septic shock?

Sepsis: severe infection with systemic inflammatory response; septic shock: sepsis with life-threatening cardiovascular collapse.

What are common etiologies and consequences of chronic inflammation?

Unresolved/repeated infections, autoimmune disorders, prolonged irritants, poor diet, obesity; contributes to asthma remodeling, IBD-associated cancer risk, atherosclerosis.

How does chronic inflammation relate to cancer and atherosclerosis?

Chronic inflammation can cause DNA mutations leading to cancer; leukocytes contribute to plaque formation in atherosclerosis.