Mast Cell

Granulocyte originating in the Bone Marrow, with peripheral target regions in the skin and connect tissue
1. Immature precursors from Bone Marrow transit to tissues, where the Mast Cells mature
2. Similar to Basophils (see below), but in contrast, Mast Cells are not found in the blood
High affinity for IgE and FceRI receptors (similar to Basophils)
1. IgE binding results in granule release with reactions as below
Functionally most similar to Basophils, and primarily responds to Immediate Hypersensitivity Reaction
1. Releases Histamine (as well as other vasoactive Cytokines and mediators stored in secretory granules)
  1. Allows for inflammatory cells to reach tissues
2. Results in wheal and flare reaction
3. Red (vasodilation)
4. Edema (vasodilation, vascular leak)