The other three types are connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of blood vessels and organs throughout the body. There are three principal shapes of epithelial cells: squamous, columnar, and cuboidal.These can be arranged in a single layer of cells as simple epithelium, either squamous, columnar or cuboidal, or in layers of two or more cells deep as stratified (layered), either squamous, columnar or cuboidal.All glands are made up of epithelial cells.pithelial tissues line the cavities and surfaces of blood vessels and organs throughout the body. There are three principal shapes of epithelial cells: squamous, columnar, and cuboidal.
Freebase(0.00 / 0 votes)Rate this definition: Tweed. Tweed is a rough, unfinished woollen fabric, of a soft, open, flexible texture, resembling cheviot or homespun, but more closely woven. It is made in either plain or twill weave and may have a check or herringbone pattern.
Tweed yarn is available in a wide range of yarn weights, or strand thicknesses, though lace weight tweed is not as common as worsted or aran weight tweed. There are two common types of short fiber used to make the colorful flecks found in tweed yarn. The first is called a nep, a small nub of fiber that is usually removed from spinning fiber during the carding process to avoid creating slubs, or thick lumps, in a finished skein of spun yarn.