Various Types of Epithelium

Description: Keratinized cells contain the cytoskeletal protein keratin. Found most often in the skin it provides an impermeable barrier.

Description: Ciliated cells have plasma membrane extensions made of microtubules that move rhythmically. Common in the respiratory system and oviduct, the cilia move mucus or other substances. Rarely occurs with stratified epithelium.

Description: Simple epithelium consists of a single layer of cells.

Description: Stratified epithelium consists of more than one layer of cells. The classification is then based on the superficial layer.

Description: Mainly occurring only as pseudostratified columnar epithelium, there is one layer of cells and cilia are often present. The position of the nuclei gives the appearance of stratification.

Description: Squamous epithelial cells are flat. They are relatively inactive metabolically and involved in the diffusion of water and electrolytes.

Description: Cuboidal epithelial cells are cube shaped with the nucleus in the center.

Description: Columnar epithelial cells are taller than they are wide. The nucleus is often near the bottom of the cell and the outer edge has microvilli, which increase the surface area of the cell to aid in absorption.

Description: Transitional epithelial cells form specialized epithelium found in organs that stretch. The cells can slide over each other and alter their appearance based on whether the tissue is contracted or relaxed.