noun, plural: mast cells
The mast cell is a type of granulocyte. It may not be found in the bloodstream but it takes a role similar to a basophil (which is also a type of granulocyte). Both the mast cell and the basophil play an essential role in inflammation and allergic reactions. Both of them have cytoplasm rich in inflammatory substances, such as histamine, cytokines, proteases, and chemotactic factors. The difference between them though is their hematopoietic lineage and location. The mast cells typically reside in tissues, especially connective tissues. The basophils are found as they circulate in the bloodstream. While the basophils are derived from the granulocytic lineage, the mast cells develop from the same stem cells but do not go through the myeloblast-band cell series. Its developmental stages are as follows: hemocytoblast → common myeloid progenitor (or CFU-GEMM) → mast cell.
There are two types of mast cells recognized: those from connective tissue and a distinct set of mucosal mast cells. The activities of the latter are T-cell dependent.
- granule cell of connective tissue
- tissue basophil