bench definition, bench meaning | English dictionary. bench. n an apparatus for experimentation in optics, typically consisting of an adjustable arrangement of light source, lenses, prisms, etc. bench.
3 Principal characteristics of cells that make up epithelium. -Cells are closely apposed-they adhere to one another via specialized cell junctions-Exhibit both structural and functional polarity-Epithelium creates a selective barrier between the external environment and the underlying connective tissue.î î î.Cells are closely apposed-they adhere to one another via specialized cell junctions-Exhibit both structural and functional polarity-Epithelium creates a selective barrier between the external environment and the underlying connective tissue. î î î.
Four layers of tissues make up the walls of the trachea: 1  The mucosa is the innermost layer and consists of ciliated pseudostratified columnar epithelium with many goblet cells. 2  Deep to the mucosa is the submucosa layer, which is made of areolar connective tissue containing blood vessels and nervous tissue.