Definition of guano. : a fertilizer containing the accumulated excrement of seabirds or bats; broadly : excrement especially of seabirds or bats.
Developmental Biology Online. Epithelial tissues come in three basic types: squamous, cuboidal and columnar. These three types of tissue are seen in either simple (only one cell layer thick) or stratified (many cells in thickness) arrangements.
Epithelium: Types of simple epithelium. Squamous means scale-like. simple squamous epithelium is a single layer of flat scale-shaped cells. Both the endothelial lining of blood vessels and the mesothelial lining of the body cavities are simple squamous epithelium.