Inflammation: Causes and Cellular Events

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Questions and Answers

What are the classical signs of acute inflammation?

Redness, heat, swelling, pain (correct)

Pain, fatigue, skin rash, shortness of breath

Fever, malaise, fatigue, swelling

Cough, nausea, vomiting, loss of appetite

Which of the following best describes a cellular exudate?

A fluid rich in white blood cells and cellular debris (correct)

A fluid that contains plasma proteins and few cells

A clear fluid without any significant cellular components

A thick fluid that is primarily composed of red blood cells

What stimuli can lead to the generation of acute inflammation?

Physical agents only

Immunological, chemical, physical, and microbial agents (correct)

Only microbial agents

Only immune response triggers

What is the primary process involved in phagocytosis?

Engulfing and digesting pathogens Signup and view all the answers

Which of the following represents a chemical mediator of inflammation?

Histamine Signup and view all the answers

What type of cellular infiltrate is primarily involved in acute inflammation?

Neutrophils Signup and view all the answers

Which of the following features is typically associated with chronic inflammation?

Fibrosis and angiogenesis Signup and view all the answers

Which is NOT one of the five cardinal signs of inflammation?

Necrosis Signup and view all the answers

What is the typical onset of acute inflammation?

Fast Signup and view all the answers

Which type of injury is most commonly associated with acute inflammation?

Trauma and infections Signup and view all the answers

What primarily characterizes chronic inflammation compared to acute inflammation?

Monocyte dominance Signup and view all the answers

Which systemic factor is likely to be prominent in acute inflammation?

Transudation of fluid Signup and view all the answers

Which type of exposure is commonly linked to chronic inflammation?

Long-term exposure to irritants Signup and view all the answers

What is the primary function of cytokines in inflammation?

To mediate and regulate immune and inflammatory reactions Signup and view all the answers

Which cytokines are known for their pro-inflammatory effects?

Interleukin (IL-1, IL-6, IL-8) and Tumor Necrosis Factor (TNF) Signup and view all the answers

What is a significant role of TNF in the inflammatory process?

Inducing fever and activating immune cells Signup and view all the answers

What effect does histamine primarily have on blood vessels?

It causes dilation of arterioles and increases permeability Signup and view all the answers

Which chemical mediator is primarily responsible for vasodilation and systemic inflammatory responses?

Prostaglandins Signup and view all the answers

Leukotrienes are primarily produced by which types of cells?

Leucocytes and mast cells Signup and view all the answers

What is the major function of chemokines in the immune response?

To act as chemo-attractants for specific leukocytes Signup and view all the answers

What distinguishes acute inflammation from chronic inflammation?

Acute inflammation is characterized by immediate onset and short duration. Signup and view all the answers

What is one of the main causes of increased vascular permeability?

Endothelial cell contraction Signup and view all the answers

Which type of phagocytic cell is part of the early inflammatory response?

Polymorphonuclear leukocytes (PMNs) Signup and view all the answers

What role do chemical mediators play in the inflammatory response?

They act upon blood vessels or inflammatory cells Signup and view all the answers

What is opsonization in the context of the immune response?

The process of marking pathogens for phagocytosis Signup and view all the answers

Which of the following is NOT a type of phagocytic cell mentioned?

Lymphocytes Signup and view all the answers

What type of inflammation is characterized by the presence of pus?

Suppurative inflammation Signup and view all the answers

What are cytokines?

Chemical proteins that mediate inflammatory responses Signup and view all the answers

Which factor contributes to leakage from new blood vessels during inflammation?

Increased transcytosis Signup and view all the answers

Study Notes

Introduction

Inflammation is a complex biological response to injury or infection
Inflammation can be acute or chronic

Acute Inflammation

Characterized by a rapid onset and a short duration
Often involves neutrophils as the primary inflammatory cells
There are five cardinal signs: rubor (redness), calor (heat), tumor (swelling), dolor (pain), and loss of function

Causes of Inflammation

Infections: Bacteria, viruses, fungi, parasites
Tissue Necrosis: Physical or chemical injuries (heart attack, burns, frostbite)
Trauma: Blunt or penetrating trauma, burns, frostbite, chemicals
Foreign bodies: Splinters, sutures, bones, finger nails, popcorn kernels
Immune (hypersensitivity) reactions: Triggered by environmental factors or autoimmune diseases

Cellular Events in Inflammation

Leukocyte recruitment:
- Chemotaxis: Movement of leukocytes towards the site of inflammation following chemical signals
Phagocytosis:
- The engulfment of particles by phagocytic cells (neutrophils and macrophages)
- Important for clearing pathogens and cellular debris

Chemical Mediators in Inflammation

Chemical messengers:
- Act upon blood vessels, inflammatory cells, or other cells to cause an inflammatory response
Two types of chemical mediators:
- Exogenous (external): From outside the body, like endotoxins
- Endogenous (internal): From within the body, produced by cells like leukocytes, endothelial cells, and fibroblasts.
Categories of Chemical Mediators:
- Cytokines
- Vasoactive amines (histamine)
- Prostaglandins
- Leukotrienes
- Chemokines

### Cytokines

Proteins produced by many cells, including macrophages, B lymphocytes, epithelial cells, and neutrophils
Important for immune cell communication, recruitment, and activation
Examples include interleukin-1, interleukin-6, interleukin-8, and Tumor Necrosis Factor (TNF)
TNF can induce fever

Vasoactive Amines

Histamine: A vasoactive amine released from mast cells
Acts on blood vessels causing dilation of arterioles and increased permeability

### Prostaglandins

Lipid compounds produced by mast cells, macrophages, and endothelial cells
Involved in vascular and systemic reactions of inflammation
Cause vasodilation, fever, and pain

### Leukotrienes

Lipid compounds produced by leukocytes and mast cells by the action of lipoxygenase
Act as chemotactic factors, attracting neutrophils to the site of inflammation
Often accompanied by histamine and prostaglandins
Release lysosomal enzymes (e.g. proteases)
Cause vasoconstriction

### Chemokines

A family of small proteins
Primarily act as chemoattractants, attracting specific types of leukocytes to the site of inflammation
Enhance chemotaxis (cell migration)

### Patterns of Acute Inflammation

Serous: Characterized by the exudation of a thin, watery fluid
Fibrinous: Characterized by the exudation of a fibrin-rich fluid
Suppurative (purulent): An inflammatory response associated with the production of pus, which is a thick, yellowish fluid containing dead neutrophils, bacteria, and other debris
Ulcerative: Inflammation associated with the formation of an ulcer, an open sore or erosion of the surface of an organ or tissue

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Description

This quiz explores the intricacies of inflammation, including its types, causes, and the cellular processes involved. Learn about acute inflammation, the role of leukocytes, and the cardinal signs associated with the response to injury or infection.