Chapter 4:
31. Some of the structural and functional characteristics of epithelial tissue its cellularity, specialized contacts, polarity, avascularity although innervated and its ability to regenerate. What this means is Epithelial tissue is composed almost entirely of close packed cells, the cells fit close together to form tight sheets, the upper free surface is exposed to body exterior, the cells are nourished by substances diffusing from blood vessels in the underlying connective tissue, and epithelial cells have a high regenerative capacity.
32. The two types of epithelia are simple epithelia and stratified epithelia. Simple epithelia are composed of a single cell layer. They are found where absorption and filtration occur and a thin epithelial barrier is desired. The other epithelia variation, stratified, consists of two or more cell layers stacked one on top of the other. Stratified epithelia are common in high­abrasion areas where protection is important, such as the skin surface and the
lining of the mouth.