Inflammation Overview

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a primary role of inflammation in the body?

To remove the initial cause of cell injury (correct)

To promote systemic toxicity

To stimulate uncontrolled cell division

To enhance nerve damage

Which component of inflammation is primarily responsible for the early phase response?

Neutrophils (correct)

Macrophages

Plasma proteins

Lymphocytes

What characteristic of acute inflammation distinguishes it from chronic inflammation?

Duration of response (correct)

Cellular infiltrate of lymphocytes

Presence of fibrosis

Systemic effects

Which of the following features is typically prominent in acute inflammation?

Erythema and stasis of blood flow Signup and view all the answers

What is the main cause of increased vascular permeability during acute inflammation?

Chemical mediators like histamine and kinins Signup and view all the answers

Which of the following outcomes may result from acute inflammation?

Resolution and repair of damaged tissue Signup and view all the answers

Which type of cell is primarily involved in the later stages of chronic inflammation?

Lymphocytes Signup and view all the answers

Which of the following best describes the tissue injury caused by chronic inflammation?

Progressive and often severe Signup and view all the answers

What is the primary role of leukocytes at sites of inflammation?

To eliminate microbes and dead cells. Signup and view all the answers

Which cytokines are primarily involved in promoting leukocyte recruitment and migration during acute inflammation?

IL-1, TNF, IL-6, and chemokines. Signup and view all the answers

What distinguishes the roles of histamine and serotonin in inflammation?

Both primarily increase vascular permeability and promote vasodilation. Signup and view all the answers

In the context of leukocyte recruitment, what role do integrins play?

They mediate the firm attachment of leukocytes to the endothelium. Signup and view all the answers

What can result from the mechanisms of leukocyte action during inflammation?

Both microbial killing and damage to normal tissues. Signup and view all the answers

Which of the following mediators is responsible for vasodilation during inflammation?

Nitric oxide (NO). Signup and view all the answers

The transition from neutrophils to macrophages in inflammatory infiltrate indicates what?

An initiation of chronic inflammation. Signup and view all the answers

Which of the following is NOT a role of reactive oxygen species (ROS) in inflammation?

Promotion of leukocyte rolling. Signup and view all the answers

What role do complement proteins play in inflammation?

Facilitating leukocyte chemotaxis and opsonization. Signup and view all the answers

Which outcome occurs primarily when there is extensive tissue destruction during acute inflammation?

Transition to chronic inflammation. Signup and view all the answers

What is primarily responsible for the increased vascular permeability observed in acute inflammation?

Direct endothelial cell injury. Signup and view all the answers

How does fibrosis primarily occur in response to inflammation?

When inflammation affects non-regenerating tissues. Signup and view all the answers

Which of the following is NOT a beneficial effect of acute inflammation?

Promotion of extensive tissue scarring. Signup and view all the answers

Which of these cells predominates during the initial stages of leukocyte migration in acute inflammation?

Neutrophils. Signup and view all the answers

What triggers the coagulation cascade in inflammation?

Activation of factor XII. Signup and view all the answers

Which condition can lead to chronic inflammation?

Prolonged exposure to toxic agents. Signup and view all the answers

What is a common characteristic of chronic inflammation?

Persistent inflammation and tissue injury Signup and view all the answers

Which cells are primarily involved in the cellular infiltrate of chronic inflammation?

Macrophages, lymphocytes, and plasma cells Signup and view all the answers

Which cytokines are notably secreted by macrophages during chronic inflammation?

IL-1 and TNF Signup and view all the answers

What systemic effect is induced by cytokines during inflammation?

Increased production of leukocytes Signup and view all the answers

Which of the following conditions is NOT a cause of granulomatous inflammation?

Rheumatoid arthritis Signup and view all the answers

What is the role of IFN-γ in chronic inflammation?

It activates macrophages and enhances their metabolism. Signup and view all the answers

What distinguishes labile tissues from permanent tissues?

Rate of cell turnover and capacity to proliferate Signup and view all the answers

In what condition might septic shock occur as a systemic effect of inflammation?

Severe infections with high levels of TNF Signup and view all the answers

What primary function does the extracellular matrix (ECM) serve in relation to tissues?

It provides mechanical support and regulates cell behavior. Signup and view all the answers

Which of the following best describes the characteristics of induced pluripotent stem cells (iPS cells)?

iPS cells are capable of differentiating into any cell type after introduction of specific genes. Signup and view all the answers

What distinguishes fibrinous inflammation from serous inflammation?

Fibrinous inflammation features a meshwork of threads from fibrin. Signup and view all the answers

What condition is indicated by the presence of a large amount of pus, particularly consisting of neutrophils and necrotic cells?

Suppurative (purulent) inflammation Signup and view all the answers

Which component of the extracellular matrix plays a crucial role in binding growth factors?

Proteoglycans Signup and view all the answers

What is a common outcome when the extracellular matrix (ECM) is damaged?

Formation of scar tissue. Signup and view all the answers

Which of the following best defines ulceration in pathological terms?

Erosion of an epithelial surface due to necrosis associated with inflammation. Signup and view all the answers

Which statement correctly describes the role of adult stem cells found in bone marrow?

They can generate multiple cell lineages for tissue repair. Signup and view all the answers

Study Notes

Inflammation

A protective response to foreign invaders and necrotic tissue, but can damage tissue itself.
Main components: vascular reaction and cellular response.
Steps: recognition, recruitment of leukocytes, removal of the agent, regulation, and resolution.
Features of acute inflammation: fast onset, mainly neutrophils in cellular infiltrate, mild and self-limited tissue injury, and prominent local and systemic signs.
Features of chronic inflammation: slow onset, monocytes/macrophages and lymphocytes in cellular infiltrate, often severe and progressive tissue injury, and less prominent local and systemic signs.

Acute Inflammation

Short duration (minutes to days).
Characterized by:
- Vasodilation: increased blood flow, leading to erythema (redness) and stasis.
- Increased vascular permeability: leakage of proteins and leukocytes into tissue, leading to edema (swelling).
- Emigration of leukocytes (mainly neutrophils) to the site of injury.
Outcomes: elimination of the stimulus and repair, or persistent injury leading to chronic inflammation.
Signs: Heat, Redness, Swelling, Pain, and Loss of Function.

Reaction of Acute Inflammation

Vasodilation is induced by histamine and other mediators.
Increased vascular permeability is induced by histamine, kinins, and other mediators.
Fluid leakage through blood vessels results in edema.

Leukocyte Recruitment to Sites of Inflammation

Leukocytes are recruited from the blood to the site of injury.
Multi-step process:
- Loose attachment and rolling: mediated by selectins.
- Firm attachment: mediated by integrins.
- Migration through interendothelial spaces.
Cytokines (TNF, IL-1, chemokines) regulate this process.

Leukocyte Effector Mechanisms

Eliminate microbes and dead cells by:
- Phagocytosis: engulfment of the target.
- Destruction in phagolysosomes: intracellular organelles.
- Release of enzymes and ROS into the extracellular environment.

Major Cell-Derived Mediators of Inflammation

Vasoactive amines (histamine, serotonin): Vasodilation and increased vascular permeability.
Arachidonic acid metabolites (prostaglandins and leukotrienes): Involved in vascular reactions, leukocyte chemotaxis, and other inflammatory reactions.
Cytokines (TNF, IL-1, IL-6, chemokines): Mediate leukocyte recruitment and migration.
ROS: Microbial killing and tissue injury.
NO: Vasodilation and microbial killing.
Lysosomal enzymes: Microbial killing and tissue injury.

Plasma Protein–Derived Mediators of Inflammation

Complement system: Mediates leukocyte chemotaxis, opsonization, phagocytosis, and cell killing.
Coagulation proteins: Trigger clotting, kinin, and complement cascades.
Kinins: Mediate vascular reactions and pain.

Sequence of Events in Acute Inflammation

Increased blood flow due to vasodilation.
Leakage of plasma proteins due to increased vascular permeability.
Leukocyte adherence and migration to the site of injury.
Phagocytosis and destruction of the offending agent.
Outcomes: resolution, chronic inflammation, or scarring.

Benificial Effects of Acute Inflammation

Dilution of toxins.
Exudation of protective antibodies.
Fibrin formation to delay bacterial spread.
Exudation of plasma mediators (complement, coagulation, fibrinolytic, and kinin)
Exudation of nutrient materials.
Promotion of immunity.

Outcomes of Acute Inflammation

Complete resolution.
Fibrosis: In tissues that do not regenerate, after substantial tissue destruction, or extensive fibrinous exudates.
Abscess formation in pyogenic infection.
Progression to chronic inflammation.

Chronic Inflammation

Longer duration (days to years).
Characterized by:
- Infiltration by mononuclear cells (monocytes, lymphocytes, and macrophages).
- Tissue destruction.
- Tissue repair (vascular proliferation and fibrosis).
Causes:
- Persistent infections (tuberculosis, syphilis).
- Prolonged exposure to toxic agents.
- Autoimmune disorders.

Features of Chronic Inflammation

Prolonged response to persistent stimulus.
Caused by microbes that resist elimination, immune responses against self or environmental antigens, or toxic substances.
Characterized by persistent inflammation, tissue injury, scarring, and immune response.
Cellular infiltrate: activated macrophages, lymphocytes, and plasma cells, with fibrosis.
Mediated by cytokines produced by macrophages and lymphocytes.

Cells in Chronic Inflammation

Macrophages: Increased in size, with more active metabolism.
Lymphocytes:
Plasma cells:
Eosinophils:

Granulomatous Inflammation

Aggregation of activated macrophages, forming granulomas.
Causes:
- Bacterial infection (tuberculosis, leprosy, syphilis).
- Parasitic infection (bilharziasis).
- Fungal infection (histoplasmosis).
- Inorganic metals (silica, berylliosis).
- Foreign body.
- Unknown (sarcoidosis).

Systemic Effects of Inflammation

Fever: Cytokines (TNF, IL-1) stimulate prostaglandin production in the hypothalamus.
Production of acute-phase proteins (C-reactive protein): Cytokines (IL-6) stimulate production in the liver.
Leukocytosis: Cytokines stimulate production of leukocytes in the bone marrow.

Septic Shock

Severe infections.
Characterized by: fall in blood pressure, disseminated intravascular coagulation, metabolic abnormalities.
Induced by high levels of TNF.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the fundamental concepts of inflammation, detailing both acute and chronic types. Participants will learn about the protective responses, core components, and the characteristics distinguishing acute inflammation from chronic inflammation. Test your understanding of the steps involved and the physiological changes during these processes.