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.
A marsh is an area of soft, wet, low-lying land, characterized by  grassy vegetation and often forming a transition zone between water  and land.   The similar wetland c â¦ alled a swamp is generally more heavily  forested.12 people found this useful. A marsh is a type of wetland. Other types of wetlands include swamps, bogs, fens, forested wetlands, and others.   A marsh is almost always inundated, or full of wate â¦ r. There is usually some open water present.