mast cell

Syllable breakdown

Dictionary meaning

a tissue-resident innate immune cell derived from bone marrow progenitors, densely packed with granules containing histamine, heparin, proteases, and other inflammatory mediators, and expressing high-affinity IgE receptors on its surface; mast cells play central roles in allergic responses and anaphylaxis, where cross-linking of IgE antibodies bound to their surface triggers rapid degranulation and the release of pre-formed mediators causing the characteristic features of allergy; they also contribute to host defence against parasites and bacteria, promote tissue repair, and are found in particularly high density at sites of environmental interface such as skin, gut mucosa, and respiratory epithelium