Inflammation Overview and Classification

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Questions and Answers

What is the primary function of the inflammatory response?

To eliminate harmful agents and damaged cells (correct)

To activate immune cells and produce antibodies

To increase blood flow to the affected area

To promote tissue repair and regeneration

Which of the following is NOT a characteristic feature of acute inflammation?

Short duration (minutes to days)

Rapid onset

Predominantly lymphocytic infiltration (correct)

Fluid and plasma protein exudation

What cellular component is primarily responsible for initiating the inflammatory response?

Epithelial cells (correct)

Neutrophils

Red blood cells

Platelets

What distinguishes chronic inflammation from acute inflammation?

Duration of inflammation (D) Signup and view all the answers

Which of the following is NOT a common stimulus for acute inflammation?

Hormonal imbalance (D) Signup and view all the answers

What is the role of phagocytes in the inflammatory response?

Destroying harmful agents and cellular debris (B) Signup and view all the answers

What is the function of dendritic cells in the inflammatory response?

Initiating adaptive immune responses (D) Signup and view all the answers

Which of the following is an example of a common cause of chronic inflammation?

Autoimmune disease (D) Signup and view all the answers

What is a key characteristic of serous inflammation?

Outpouring of a watery fluid low in protein (C) Signup and view all the answers

What is the main difference between chronic and acute inflammation?

Acute inflammation is typically short-lived, while chronic inflammation can persist for extended periods. (B) Signup and view all the answers

What occurs during fibrinous inflammation?

Increased vascular permeability allows for the passage of large molecules like fibrinogen. (C) Signup and view all the answers

What is the main component of purulent exudate?

Neutrophils (B) Signup and view all the answers

Which of the following conditions is NOT a possible outcome of chronic inflammation?

Severe bleeding (A) Signup and view all the answers

What is the main cause of the redness (erythema) and warmth that characterize acute inflammation?

Arteriolar vasodilation (B) Signup and view all the answers

What is the primary function of leukocytes in an inflammatory response?

To eliminate offending agents and foreign substances (B) Signup and view all the answers

What is the difference between transudate and exudate?

Exudate is formed due to increased vascular permeability, while transudate is formed due to increased hydrostatic pressure or decreased osmotic pressure. (C) Signup and view all the answers

What is the cause of tissue edema in inflammation?

Increased osmotic pressure in the interstitial fluid (A) Signup and view all the answers

What are pattern recognition receptors, and why are they so named?

Receptors that recognize common structures on microbes or dead cells. (C) Signup and view all the answers

Which of the following is NOT a characteristic of acute inflammation?

Formation of granulomas (A) Signup and view all the answers

How does increased vascular permeability contribute to the formation of exudate?

It allows protein-rich fluid to leak out of the blood vessels into the tissues. (B) Signup and view all the answers

What is the potential downside of leukocyte activation in inflammation?

They can damage normal host tissues. (A) Signup and view all the answers

What is the primary mechanism by which leukocytes are recruited to the site of injury or infection?

A sequential process involving margination, adhesion, transmigration, and chemotaxis (B) Signup and view all the answers

Which of the following molecules plays a crucial role in regulating leukocyte recruitment and activation?

Chemokines (B) Signup and view all the answers

During the process of leukocyte migration, what is the immediate step that follows firm adhesion to the endothelium?

Transmigration (C) Signup and view all the answers

What are the primary stimuli that trigger leukocyte activation?

Microbes, necrotic cells, and inflammatory mediators (C) Signup and view all the answers

What is the role of opsonins in phagocytosis?

Facilitate the recognition and attachment of particles to leukocytes (B) Signup and view all the answers

Which of the following is NOT a typical outcome of acute inflammation?

Formation of a fibrous capsule (C) Signup and view all the answers

Which of the following statements describes the process of 'resolution' in acute inflammation?

The damaged tissue is completely repaired and restored to its normal state. (C) Signup and view all the answers

What is the main function of lysosomes in phagocytosis?

To degrade and destroy the ingested material (A) Signup and view all the answers

Study Notes

Inflammation

Inflammation is a complex host response to eliminate foreign invaders
It's a protective response involving host cells, blood vessels, and proteins
The goal is to eliminate the initial cause of injury, necrotic cells, and initiate tissue repair
Harmful agents are diluted, destroyed, or neutralized

Classification of Inflammation

Acute inflammation
- Rapid onset, short duration (minutes to days)
- Characterized by fluid and protein exudation, and neutrophilic leukocyte accumulation
Chronic inflammation
- More insidious, longer duration (days to years)
- Influx of lymphocytes, macrophages, and associated vascular proliferation and fibrosis (scarring)

Induction of Inflammation

Induced by chemical mediators produced by host cells in response to harmful stimuli
Resident cells (macrophages, dendritic cells, mast cells) sense infection or injury
Cytokines and other mediators induce and regulate the inflammatory response

Cardinal Signs of Inflammation

External manifestations are heat, redness, swelling, pain, and loss of function

Steps of the Inflammatory Response (Five Rs)

Recognition of the injurious agent
Recruitment of leukocytes
Removal of the agent
Regulation (control) of the response
Resolution (repair)

Vascular Changes in Inflammation

Increased blood flow (vasodilation) and increased vascular permeability
Initial transient vasoconstriction, followed by vasodilation
Increased vessel permeability allows plasma proteins to leave the circulation
Fluid leakage leads to edema

Cellular Events (Leukocyte Recruitment and Activation)

Leukocytes are delivered to the site of injury and activated for function
Leukocytes ingest harmful agents, kill microbes, and eliminate necrotic tissue
However, leukocyte products can damage normal tissues
Host defense mechanisms include checks and balances

Leukocyte Recruitment

Leukocytes circulate rapidly in blood, but in inflammation, they adhere, then migrate to the site of injury
Margination, rolling, adhesion, transmigration, and migration constitute the sequence of events

Leukocyte Activation

Once leukocytes are recruited, stimuli like microbes, necrotic products, activate them
Leukocytes use receptors to sense harmful stimuli, inducing a series of responses (leukocyte activation)

Phagocytosis

Three steps:
- Recognition and attachment of the particle (microbes, dead cells) to the leukocyte
- Engulfment, forming a phagocytic vacuole for the ingested particle
- Killing and degradation of the ingested particle through introduction of microbicidal substances within lysosomes

Outcomes of Acute Inflammation

Resolution: Regeneration and repair (tissue regeneration and function restoration)
Chronic inflammation: follows if the offending agent is not removed and tissues cannot regenerate; possible scarring
Scarring: inflammation in non-regenerating tissues leads to fibrosis where connective tissue fills the injury site

Morphologic Patterns of Acute Inflammation

Serous inflammation: outpouring of watery, protein-poor fluid (e.g., blister)
Fibrinous inflammation: severe injuries with large molecules (like fibrinogen), exudates
Suppurative (purulent) inflammation/abscess: pus formation (neutrophils, necrotic cells, edema), focal collections of pus
Ulcers: local defects in tissue surfaces resulting from necrosis, inflammatory tissue destruction

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Description

Explore the complex process of inflammation, including its classification into acute and chronic forms. Understand how inflammation serves as a protective response involving various host cells and mediators. This quiz provides insights into the mechanisms and purposes of inflammation in the body.