Acute Inflammation and Its Complications Quiz

Inflammation Overview

• Inflammation is the body's protective response to injury or harmful stimuli.
• The goal of inflammation is to eliminate the initial cause of tissue injury, remove damaged tissue, and initiate repair.
• Inflammation can be acute or chronic.

Acute Inflammation

• Characterized by rapid onset (seconds to minutes) and short duration (minutes to days).
• Involves fluid exudation (edema) and the emigration of neutrophils.
• Key cells are neutrophils.
• Outcomes may include full resolution, healing (fibrosis/scarring), or progression to chronic inflammation.
• Acute inflammation is influenced by the nature and intensity of the injury, the tissue involved, and the host's responsiveness to the stimulus.

Chronic Inflammation

• Characterized by a delayed onset and prolonged duration (weeks to years).
• Involves lymphocytes and macrophages, with blood vessel proliferation and fibrosis (scarring).
• Results from persistent inflammation and can lead to tissue damage or even disease.

Causes of Inflammation

• Exogenous causes: External factors, including mechanical (fractures, foreign bodies, thermal), chemical (acids, bases, toxins), and biological (bacteria, viruses, parasites).
• Endogenous causes: Internal factors such as circulation disorders (thrombosis, infarction, hemorrhage, hypoxia), enzyme activation (acute pancreatitis), metabolic products (uric acid), and immune responses.

Classification of Inflammation

• Classified based on: duration (acute, subacute, chronic); reactivity of the organism (normoergic, hyperergic, hypoergic, anergic); predominant component (alterative, exudative, proliferative).

Types of Exudative Inflammation

• Serous: Exudate with relatively few cells and a lot of protein. Examples include skin blisters, inflammation of serous membranes (pleura, pericardium, peritoneum, joints), and some viral/bacterial infections.
• Catarrhal: Characterized by an exudate rich in mucus. Common instances include the common cold, bronchitis, and gastroenteritis.
• Fibrinous: The exudate contains fibrin and has a thick, sticky consistency. Often caused by bacterial, viral, or other infections causing tissue injury. A few examples are fibrinous pericarditis, pleuritis, and certain infections.
• Purulent: Characterized by a thick, creamy, yellow, or greenish exudate. This exudate contains neutrophils. A few examples are abscesses, boils, and empyema of the pleural cavity.
• Hemorrhagic: The exudate contains blood due to extensive vascular injury, indicative of severe damage or inflammation.
• Putrefactive: Necrosis, caused by anaerobic bacteria, leading to a foul-smelling exudate. Examples often have severe course and can be life-threatening.

Types of Proliferative Inflammation

• Granulomatous: Characterized by the formation of granulomas ("nodules"). Granulomas are a specific type of chronic inflammation.

General features of the Inflammatory Process

• Non-specific: Response to a variety of threats.
• Dynamic: A series of complex steps, often involving both activation and inhibition/modulation.
• Tightly regulated: Ensures that the response is proportionate to the threat.
• White blood cells, or leukocytes, and plasma proteins are also components of the inflammatory process. These usually reside in the blood, but must move to the area of injury.

Goals of Inflammation

• Eliminate the cause of tissue injury (harmful agents)
• Remove damaged tissue
• Initiate the process of repair.

Systemic Signs of Inflammation:

• Fever, leukocytosis. increased ESR, acute-phase proteins, and lymphoid hyperplasia are indicators of inflammation spreading beyond the initial site.

Outcomes of Acute Inflammation

• Complete resolution: The damaged tissue is fully repaired, and function returns to normal.
• Healing by connective tissue (scarring): Chronic inflammation, unresolved tissue injury, abscess formation can result in fibrosis and scar tissue.
• Progress to chronic inflammation: When a stimulus persists, the response may transform into chronic inflammation leading to further tissue damage or disease.

Complications of Inflammation

• Spread of inflammation to other organ systems.
• Systemic inflammatory response syndrome, sepsis, and other associated conditions are possible complications of persistent and widespread inflammation.