Simple cuboidal epithelium is a layer of cube-like shape cells, i.e are as wide as tall. This can be observed when they are cut perpendicularly to the epithelial surface. The nucleus is rounded and located centrally or slightly basal in the cell. Sometimes, the apical surface of the cell shows cilia or flagella. This type of epithelium lines many ducts and tubes such as secretory ducts (thyroid gland), excretory ducts (exocrine gland ducts) and ducts for absorption/excretion (renal tubules) or respiratory ducts (lung bronchioles).