First to appear in acute inflammation is ?
**Core Concept**
Acute inflammation is a complex physiological response to tissue injury or infection, characterized by the activation of various cellular and molecular mechanisms. The process begins with the recruitment of immune cells to the site of injury or infection, leading to the release of chemical mediators and the initiation of an inflammatory response.
**Why the Correct Answer is Right**
The correct answer is **Neutrophils**. Neutrophils are the first line of defense in acute inflammation, arriving at the site of injury or infection within 1-2 hours. They play a crucial role in phagocytosing foreign particles and microorganisms, and releasing granules containing enzymes and antimicrobial peptides. The rapid recruitment of neutrophils to the site of inflammation is mediated by chemokines, such as IL-8, which bind to specific receptors on the surface of neutrophils, triggering their migration.
**Why Each Wrong Option is Incorrect**
**Option A:** Macrophages are not the first cells to appear in acute inflammation, but rather play a key role in the resolution of inflammation and the clearance of apoptotic cells.
**Option B:** Eosinophils are involved in allergic reactions and parasitic infections, but are not typically the first cells to appear in acute inflammation.
**Option C:** Basophils are involved in allergic reactions and anaphylaxis, but are not typically the first cells to appear in acute inflammation.
**Clinical Pearl / High-Yield Fact**
It's worth noting that the order of cell recruitment in acute inflammation is generally as follows: neutrophils (first), followed by macrophages, lymphocytes, and eosinophils.
**Correct Answer:** C. Neutrophils.