noun, plural: simple columnar epithelia
Simple epithelium composed of columnar epithelial cells
A simple epithelium is an epithelial tissue that is composed of a single layer of epithelial cells. These cells are in direct contact with the basement membrane. This tissue may be classified histologically according to the shape of the cells it is made up of. It may be squamous (scale-like), cuboidal (cube-like), or columnar (column-like).
A simple columnar epithelium is a simple epithelium made up of columnar epithelial cells. The columnar epithelial cells are characterized by being taller than wide, i.e. the height is about four times the width. The nucleus is elongated and near the base of the cell. The cells may be ciliated or non-ciliated. Some simple columnar epithelia may form microvilli projections.
The simple columnar epithelium is mainly involved in secretion, excretion, and absorption. The ciliated type can be found in the bronchi, uterine tubes, the uterus, and part of the spinal cord. These epithelia are capable of moving mucus or other substances through the beating of their cilia. The cilia also aid in generating currents in the lumen of the uterine tube and consequently help propel the egg cell toward the uterus.
The non-ciliated simple columnar epithelium is found in the digestive tract and urinary bladder.
- simple columnar epithelial tissue