Specific granule

{{Short description|Secretory vesicles within the immune system}}

Specific granules are secretory vesicles found exclusively in cells of the immune system called granulocytes.

It is sometimes described as applying specifically to neutrophils,{{cite web |url=http://cancerweb.ncl.ac.uk/cgi-bin/omd?specific+granule |title=Definition: specific granule from Online Medical Dictionary }} and sometimes the term is applied to other types of cells.{{cite journal |vauthors=Okuda M, Takenaka T, Kawabori S, Ogami Y |title=Ultrastructural study of the specific granule of the human eosinophil |journal=J. Submicrosc. Cytol. |volume=13 |issue=3 |pages=465–71 |date=July 1981 |pmid=7334549 }}

These granules store a mixture of cytotoxic molecules, including many enzymes and antimicrobial peptides, that are released by a process called degranulation following activation of the granulocyte by an immune stimulus.

Specific granules are also known as "secondary granules".{{cite book|author1=John P. Greer|author2=Maxwell Myer Wintrobe|title=Wintrobe's clinical hematology|url=https://books.google.com/books?id=68enzUD7BVgC&pg=PA173|access-date=10 November 2010|date=1 December 2008|publisher=Lippincott Williams & Wilkins|isbn=978-0-7817-6507-7|pages=173–}}