What is a technical term for that in English? I mean tiny fibers only seen under microscope or by means of macro photography, the ones that some living organisms develop in order to be in a better touch with the outside. For example, such is the surface of leaves, or the lining of an intestine, that allows for a closer contact with the outside environment and for a better absorption of whatever the organism needs to survive. Would the word "fiber" do it? Or, is there another more technical term? In Russian, ворсинки is the term used in botany for plants, and in anatomy for tissues. I am talking about living organisms that are programmed to live, that will do anything to just hold on to being under the sun, even break through the mud, lift up asphalt, and hold to the last drop of water with each one of their tiny fibers.