Leukemias are cancers of the blood. Lymphomas are cancers of reticular connective tissue. Cancers are more likely in tissue with higher rates of cell division. Epithelial Tissues a. Epithelium consists of tightly packed cells forming a continuous sheet over the body surface and internal cavities. Lung epithelium has cilia that brush up impurities.
Intestinal epithelium absorbs molecules with microvilli.
Simple squamous epithelium is flattened cells. Cuboidal epithelium has cube-shaped cells. Pseudostratified appears to be layered but true layers do not exist because each cell touches a basement membrane that joins epithelium to underlying connective tissue. A gland may be a single epithelial cell such as a goblet cell in digestive tract that produces mucus. Tight junctions form an impermeable barrier because adjacent membrane proteins join, producing a zipperlike fastening.