A plasmodesma (also plasmodesmata ) is a thin, from a plasma membrane surrounded plasma strand formed by the cell wall of a plant cell through provides a connection to the neighbor cell. Thanks to such plasmodesmata, the exchange of substances across the cell boundary can be carried out, which is vital for the cell. A plasmodesmos is traversed by a central cord (Desmotubulus). This is a local modification of the endoplasmic reticulum (ER), which makes contact with cisterns of the ER on both adjacent cells.
The singular forms plasmodesmos and plasmodesma are used equally in German and are derived from the Greek plasmo- "the structure, the formed" and -desmos (or neo-Latin desma ) "the band". More common than one of the singular forms in the life sciences are the plural forms plasmodesmata / plasmodesmata .