Stratified cuboidal epithelium is one of the many types of epithelial tissue. It is less common than other types of epithelial tissue, and it has several locations in the body: sweat gland ducts; egg-producing vesicles, or follicles, of the ovaries; and sperm-producing ducts, or seminiferous tubules, of the testis. The functions of this tissue include sweat secretion, aiding in sperm production and secretion of ovarian hormones.
In general, epithelial tissue lines the inner and outer surfaces of the body and its cavities, and it forms glands. Its primary functions include protection, support, secretion and absorption. All epithelial cells have shared characteristics but differ in their shape and structure.
Tissues are classified into two main categories, simple or stratified. Simple tissue has only one layer of cells, and stratified has two or more. Epithelial tissue is further classified by its cell shape. Squamous epithelia are flat and scale-like in appearance, cuboidal epithelia are cube shaped, and columnar epithelia are tall, narrow cells that resemble pillars.
Stratified cuboidal epithelium is made up of two or more layers of cells. There are rarely more than four layers of cuboidal epithelium. Having more than one layer of cells helps the tissue better withstand chemical and physical assault from outside forces. This allows the outer layer of cells to slough off or become damaged without harming the layers of cells below.
In areas that benefit from being multi-layered, stratified cells are common. Areas exposed to a greater potential for damage such as the anal canal, vagina, esophagus and most ducts are lined with stratified epithelium. Having several layers allows the tissue to repair itself by rapidly producing new cells.
Stratified cuboidal cells might be square, round or hexagonal in shape. They have equal dimensions on all sides. When a cross-section of stratified cuboidal epithelium is viewed under the microscope, it usually appears as a double or triple layer of round, flat cells packed together. There is also a large, round central nucleus in each cell.
Like all epithelial tissue, stratified cuboidal epithelium is avascular, which means that it lacks blood vessels. The bottom row of stratified cuboidal cells sits on a basement membrane, and the uppermost row is freely exposed to a body cavity. The basement membrane anchors the cells to connective tissue below. The connective tissue is what supplies the stratified cuboidal epithelial cells with nutrients, oxygen and a means of waste removal. It accomplishes this by means of diffusion.