Which of the following secretes histamine
**Core Concept**
The release of histamine is a key component of the body's allergic response, mediated through the immune system's mast cells. Histamine is a biogenic amine that plays a crucial role in the inflammatory response, causing blood vessels to dilate and increasing vascular permeability.
**Why the Correct Answer is Right**
Mast cells, a type of immune system cell, contain granules that store histamine. When activated by an allergen or other stimulus, mast cells degranulate, releasing histamine into the surrounding tissue. Histamine then binds to its receptors on nearby cells, causing a cascade of effects that lead to inflammation and increased vascular permeability. This process is a critical component of allergic reactions, including anaphylaxis.
**Why Each Wrong Option is Incorrect**
* **Option A:** While basophils also contain histamine and play a role in allergic reactions, they are not the primary source of histamine secretion in this context.
* **Option B:** Eosinophils are involved in the body's response to parasites and in certain allergic reactions, but they are not directly responsible for secreting histamine.
* **Option C:** Neutrophils are a type of white blood cell involved in the body's response to infection, but they do not typically secrete histamine.
**Clinical Pearl / High-Yield Fact**
Mast cells are found in various tissues throughout the body, including the skin, lungs, and gastrointestinal tract, making them a key component of the body's allergic response in these areas.
**Correct Answer:** D. Mast cells.