Inflammation Overview and Types

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Questions and Answers

What is the primary purpose of inflammation?

To primarily aid in the growth of new blood vessels

To eliminate the initial cause of cell injury and initiate repair (correct)

To consistently promote tissue necrosis

To repair tissues without addressing the underlying cause

Which type of cell is primarily involved in acute inflammation?

Eosinophils

Macrophages

Lymphocytes

Neutrophils (correct)

Which hallmark sign is NOT associated with inflammation?

Swelling

Chronic fatigue (correct)

Redness

Pain

What characterizes chronic inflammation compared to acute inflammation?

Insidious onset and long duration Signup and view all the answers

Which process is NOT a characteristic of acute inflammation?

Initiation of vascular proliferation Signup and view all the answers

What is the primary characteristic that distinguishes exudate from transudate?

Presence of inflammatory cells Signup and view all the answers

Which of the following statements accurately describes the main roles of acute inflammation?

It promotes the removal of dead tissue and delivers cells to the injury site. Signup and view all the answers

Which type of fluid is characterized by a specific gravity of 1.012 or less?

Transudate Signup and view all the answers

During inflammation, which component is responsible for the formation of exudate?

Increased vascular permeability Signup and view all the answers

Which of the following statements is NOT true concerning pus?

It consists primarily of plasma proteins. Signup and view all the answers

What is the primary mechanism by which neutrophils kill microbes?

Oxidative burst Signup and view all the answers

During phagocytosis, which structure is formed after the binding of microbial targets?

Phagosome Signup and view all the answers

Which of the following is NOT a component of the neutrophil's extracellular traps (NETs)?

Lipid vesicles Signup and view all the answers

What can lead to frustrated phagocytosis?

Damage to phagolysosomal membrane Signup and view all the answers

Which protein is involved in enhancing the permeability of bacterial membranes?

Bactericidal permeability increasing protein Signup and view all the answers

What is primarily mediated by integrins on leukocytes?

Adhesion to endothelial cells Signup and view all the answers

Which molecule is involved in the migration of leukocytes through the vessel wall?

PECAM-1 Signup and view all the answers

Which type of agents are known to induce chemotaxis in leukocytes?

Bacterial peptides and lipids Signup and view all the answers

What is the term for the process where leukocytes squeeze between endothelial cells?

Diapedesis Signup and view all the answers

What enhances leukocyte activation in response to stimuli?

Induction of responses in leukocytes Signup and view all the answers

During chemotaxis, leukocytes move towards a chemical gradient driven by which of the following?

Presence of chemokines Signup and view all the answers

What role do leukocytes play in the destruction of phagocytosed material?

Liberation of substances Signup and view all the answers

Which receptor helps leukocytes adhere to the extracellular matrix during movement?

Integrin receptors Signup and view all the answers

What is one mechanism that contributes to increased vascular permeability during inflammation?

Endothelial injury Signup and view all the answers

What role do mediators like Vascular Endothelial Growth Factor (VEGF) play in increased vascular permeability?

They promote the formation of new blood vessels Signup and view all the answers

What typically occurs during the first 6-24 hours of acute inflammation?

Neutrophils predominate Signup and view all the answers

Which process is responsible for the movement of leukocytes from the circulation to the site of injury?

Chemotaxis Signup and view all the answers

What is the significance of margination in the inflammatory response?

It facilitates leukocyte adhesion to the endothelium Signup and view all the answers

What does the term 'diapedesis' refer to in the context of inflammation?

Transmigration through the blood vessel wall Signup and view all the answers

What inflammatory condition involves red streaks at the wound site and enlarged painful lymph nodes?

Lymphangitis Signup and view all the answers

During the healing process, what primarily contributes to the permeability of new blood vessels?

Poorly developed inter-cellular junctions Signup and view all the answers

Study Notes

Inflammation Definition

A protective response by the body that involves cells, vessels, and proteins to eliminate injury and initiate repair.
Aims to dilute, isolate, destroy, or neutralize harmful agents.
Part of innate immunity.
Components of defense are brought to the site of damage.
Strong, prolonged, or inappropriate inflammatory reactions can harm normal tissues.

Types of Inflammation

Acute Inflammation:
- Rapid onset.
- Short duration (minutes to days).
- Characterized by edema, exudate, and neutrophil migration.
- Local and systemic signs are prominent.
Chronic Inflammation:
- Insidious onset.
- Long duration (days to years).
- Characterized by vascular proliferation, fibrosis, and tissue necrosis.
- Lymphocytes and macrophages are the predominant leukocytes.
- Local and systemic signs are less prominent.

Cardinal Signs of Inflammation

Redness (Rubor): Due to hyperemia (increased blood flow).
Heat (Calor): Also caused by hyperemia.
Swelling (Tumor): Caused by exudation.
Pain (Dolor): Caused by nerve stimulation by chemical mediators.
Loss of Function (Functio Laesa): Resulting from pain, swelling, and tissue damage.

Triple Response

Characterized by flare, flush, and weal.
Also known as "red, warm, and swollen."

Definitions

Exudate: Fluid rich in proteins and cells that escapes from the vascular system into interstitial tissues or body cavities.
- Caused by increased vascular permeability.
- Specific gravity greater than 1.020.
Pus: Exudate rich in leukocytes and parenchymal cell debris.
Transudate: Ultrafiltration of blood plasma due to increased hydrostatic pressure in vessels.
- No increase in vascular permeability.
- Fluid contains very little protein (mostly albumin).
- Specific gravity less than 1.012.

Exudate vs. Transudate

Feature	Exudate	Transudate
Permeability	Increased	Normal
Protein	1.5-6 g/dL	0-1.5 g/dL
Protein Type	All	Albumin
Specific Gravity	1.015-1.027	1.010-1.015
Cells	Inflammatory	None

Components of Inflammatory Response

Circulating Cells: Neutrophils, eosinophils, basophils, lymphocytes, monocytes, and platelets.
Plasma Proteins: Clotting factors, complement proteins, kininogens.
Vascular Wall Cells: Endothelial cells and smooth muscle cells.
Surrounding Connective Tissue:
- Cells: Mast cells, lymphocytes, macrophages, fibroblasts.
- Extracellular matrix: Collagen, elastin, proteoglycans, glycoproteins.

Acute Inflammation

The immediate and early response to injury, designed to deliver leukocytes and plasma proteins to the injury site.
Non-specific.
Main Roles:
- Formation of exudate: To dilute, isolate, and neutralize harmful agents.
- Elimination of the cause: To protect against microorganisms.
- Breakdown and removal of dead tissue: To initiate repair.
Vascular Events:
- Increased vascular permeability:
  - Endothelial injury: Caused by direct injury or leukocyte-mediated damage.
  - Increased transcytosis: Mediated by mediators such as VEGF.
  - Leakage from new blood vessels: New blood vessels are leaky during healing.
Lymphatic Vessel Responses:
- Increased lymph flow: Drains edema fluid, leukocytes, and debris.
- Lymphangitis and lymphadenitis: Red streaks at the wound site and enlarged painful lymph nodes.

Cellular Events

Leukocyte Recruitment and Emigration:
- Margination and rolling: Leukocytes accumulate at the periphery of vessels.
- Adhesion to endothelium: Mediated by selectins and integrins.
- Transmigration through the wall (Diapedesis): Leukocytes squeeze between endothelial cells.
- Migration in the interstitium (Chemotaxis): Leukocytes move towards a chemical gradient.
Leukocyte Activation:
- Phagocytosis: Engulfment and destruction of foreign substances or microbes.
- Extracellular excretion of lysosomal contents: Release of lysosomal enzymes to combat microbes.
- Neutrophil Extracellular Traps (NETs): Fibrin networks with antimicrobial peptides that trap pathogens.

Leukocytes and Tissue Injury

Leukocytes can damage tissues during normal defense in severe infections.
Autoimmunity and hypersensitivity: Can lead to excessive tissue damage.

Neutrophils and Monocytes in Acute Inflammation

Neutrophils are the predominant leukocytes in the first 6-24 hours.
Monocytes replace neutrophils in 24-48 hours.

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Description

This quiz explores the definition and types of inflammation, including acute and chronic forms. It covers the body's protective response, the cardinal signs of inflammation, and the implications of prolonged inflammatory reactions. Test your knowledge on this essential aspect of innate immunity.