Title: Neutrophilic granulocytes in peripheral blood smear (human)
Description: Stain: May-Grünwald-Giemsa (MGG).
The nucleus of the neutrophilic granulocytes (also called polymorphonuclear leukocyte or PMN) is segmented into three to five connected lobules. The cytoplasm displays many fine (dust-like) azurophilic granules. The majority called specific granules are filled with enzymes such as lysozyme, collagenase, and elastase. These granules do not stain strongly with either basic or acidic dyes. The remainder of the granules, called azurophilic granules, contain enzymes and microbicidal substances.
Background: Neutrophils (and also macrophages) express cell surface receptors that recognize microbes which are subsequently ingested and degraded in phagolysosomes. Samples of receptors are mannose receptors and scavenger receptors, receptors for opsonins (Ig and complement factors), Toll-like receptors (TLR’s), G protein–coupled receptors .The actual killing mechanism for microbes consists of generation of reactive oxygen intermediates (ROI’s, respiratory burst), and reactive nitric oxid intermediates (iNOS). In addition they can release also cytokines (TNF, IL-12) to enhance inflammation reaction. See also POJA-L604 legends for the specification of the four types of granules.
Keywords/Mesh: blood, bone marrow, neutrophilic granulocyte, histology, POJA collection