Final answer:
Reactive granulocytosis refers to an increase in granulocytes, including neutrophils, eosinophils, and basophils, which are crucial for the body's immune response to infection, inflammation, or stress. These cells contain granules with histamine and other mediator substances that participate in creating inflammatory reactions and allergic symptoms when released.
Step-by-step explanation:
Reactive granulocytosis is a histological term that refers to an increase in the number of granulocytes, a type of leukocyte (white blood cell), in response to various triggers such as infection, inflammation, or stress. Granulocytes include neutrophils, eosinophils, and basophils, all of which play crucial roles in the body's immune response. Neutrophils are particularly significant as they act as first responders to sites of infection, moving from the bloodstream to infected tissues via chemotaxis. These cells are characterized by their granular inclusions in the cytoplasm, which contain a variety of mediators, including histamine.
Eosinophils, which can be identified by their granules that stain red with eosin, are primarily involved in fighting parasitic infections and are also associated with allergic reactions. Basophils contain granules that release histamine and heparin, contributing to inflammation and opposing blood clotting, respectively. High basophil counts can be indicative of allergies and parasitic infections, while low counts may be observed in conditions like pregnancy and stress.
Mast cells, which are similar in function to granulocytes, are located in connective tissues and also contain granules rich in histamine and heparin. Upon activation, mast cells release these substances, leading to common allergic symptoms such as vasodilation, increased blood flow, and swelling. Eosinophils and mast cells also have a role in the modulation of allergic responses, with eosinophils releasing antihistamines to counteract the effects of histamine.