Answer:columnar describes cell shape.
Simple describe the number of layers
Explanation: epithelial tissues are one of the four major tissues of the body.the others being nervous, muscular, connective tissues.
Epithelial tissues are made up of thin cells that cover the external and internal surface of the body.
The cells may form one layer or more and they occur in several shapes.if they form one layer ,it is called simple.if they form several layers,it is called stratified.
Some are called pseudo-stratified because the cells occur with varying lengths and give the impression of stratified but they are actually made up of one layer.
Simple columnar epithelium is a single layer of tall, closely packed cells. They possess cellular extensions ,such as microvilli in the small intestine, or the cilia in the female reproductive tract.
They do the same thing that all living and breathing things do! They breathe! When they breathe they are doing the same thing you are doing all day everyday. Inhaling oxygen and exhaling carbon dioxide.
TRUE, with also sharp points
Http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072434/
There is a website with some info. Hope it helps! :)