The glands that secrete hormones comprise the endocrine signaling system. The term hormone is sometimes extended to include chemicals produced by cells that affect the same cell (autocrine or intracrine signalling) or nearby cells (paracrine signalling).
A fen is one of the main types of wetland, the others being grassy marshes, forested swamps, and peaty bogs. Along with bogs, fens are a kind of mire. Fens are usually fed by mineral-rich surface water or groundwater.
Medical Definition of FENNEL. : a perennial European herb (Foeniculum vulgare) of the carrot family (Umbelliferae) introduced into North America and cultivated for its aromatic seeds and its foliage.ull Definition of FENNEL. : a perennial European herb (Foeniculum vulgare) of the carrot family having two cultivated forms: a: the commonly cultivated form (F. vulgare dulce) having aromatic leaves and seeds b: Florence fennel. See fennel defined for English-language learners. See fennel defined for kids. ADVERTISEMENT.