For each of the following tissue types describe the structure of the cells and tissue?

A. Simple columnar epithelial tissue's structure is cells shaped like columns joined tightly to one another along their sides. The nuclei are at the bottoms of the cells. This tissue is found throughout most of the digestive system, everywhere except the mouth and esophagus. The tight connections between the cells prevent pathogens from traveling from your food to your blood. But the cell membranes are permeable to chemicals to and from the blood, and some of these cells are specialized to absorb nutrients from food, in particular the cells in the small intestines.

B. Stratified squamous epithelial tissue is well suited to areas in the body subject to constant abrasion, as it is the thickest and layers can be sequentially sloughed off and replaced before the basement membrane is exposed. It is composed of a basement membrane at the bottom, then cells that are more or less round, then gradually the cells get flatter and die off toward the top. The top cells are flat, and they're dead husks, so the body doesn't miss them much. This type of tissue is the lining for the mouth and esophagus.