Simple Squamous Epithelium Description: There is only one cell layer, and each cell is in direct touch with the basement membrane underneath it. Location: blood and lymphatic vessels, air sacs of lungs, lining of the heart Function: secrets lubricating substance, allows diffusion and filtration Simple Cuboidal Epithelium Description: is made up of a single layer of cuboidal cells with big, spherical nuclei at the center. Location: secretory ducts of small glands, kidney tubules Function: allows secretion and absorbtion Ciliated Simple Columnar Epithelium Description: a single layer of tall, thin columnar epithelial cells with oval-shaped nuclei that are connected to the basement membrane in the basal area. Location: bronchi, uterine tubes, uterus Function: allows absorbtion, secretes mucous and enzymes