Question

The process of acute inflammation is initiated by the action of

• A. Vasoactive amines
• B. Complement
• C. Thromboplastin
• D. Antibody

Hint:

The very first responders in tissue injury are mast cells releasing Histamine (a classic Vasoactive Amine).
This initiates the hallmark redness and swelling of acute inflammation.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Inflammation is a protective tissue response to cellular injury, infection, or irritation, aimed at neutralizing the damaging agent and initiating tissue repair.
Acute inflammation is characterized by rapid onset, vasodilation, and increased vascular permeability.

Step 2: Detailed Explanation:
The immediate, early phase of acute inflammation is driven by the release of chemical mediators from pre-formed stores in local tissue cells.
When cells are injured or pathogens enter, local mast cells, basophils, and platelets immediately degranulate, releasing vasoactive amines (primarily histamine and serotonin).
These vasoactive amines act directly on local blood vessels, causing:
1. Vasodilation (widening of blood vessels), which increases local blood flow, causing redness and heat.
2. Increased vascular permeability (opening junctions between endothelial cells), allowing fluid, plasma proteins, and white blood cells (neutrophils) to leave the bloodstream and enter the injured tissue, causing swelling (edema).
While the complement system, antibodies, and clotting factors (like thromboplastin) play vital roles in sustaining, amplifying, and coordinating the inflammatory response, the initial trigger that starts acute inflammation is the action of these released vasoactive amines.

Step 3: Final Answer:
The process of acute inflammation is initiated by the action of Vasoactive amines.