Title: Neutrophilic granulocyte with drumstick in peripheral blood smear (human)
Description: Stain: May-Grünwald-Giemsa (MGG).
(1): This neutrophil has a segmented lobulated nucleus with one drumstick (→) and one non-specific appendage (small club). The cytoplasm is filled with very fine granules.
(2): Small (smudged) lymphocyte with a dark condensed, indented nucleus and a small rim of cytoplasm.
Background: The majority of the neutrophilic granules are specific granules filled with enzymes such as lysozyme, collagenase, and elastase. These granules do not stain strongly with either basic or acidic dyes. The remainder azurophilic granules contain enzymes and microbicidal substances.
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 characteristics of the different types of granules.
Keywords/Mesh: blood, bone marrow, neutrophilic granulocyte, lymphocyte, histology, POJA collection