Simple columnar epithelium

Epithelial tissue is composed of cells laid together in sheets with the cells tightly connected to one another. Epithelial layers are avascular, but innervated. Epithelial cells have two surfaces that differ in both structure and function.

Epithelial tissue covers the outside of the body and lines organs, vessels (blood and lymph), and cavities. Epithelial cells form the thin layer of cells known as the endothelium, which is contiguous with the inner tissue lining of organs such as the brain, lungs, skin, and heart.

Epithelial Tissue Epithelium also lines internal cavities and passageways such as the chest, brain, eye, inner surfaces of blood vessels, the heart, and the inner ear. Functions of epithelium include: Providing physical protection from abrasion, dehydration, and damage by xenobiotics .

It is covered with epithelial cells that protect your body by being a barrier between your internal cells and the dirt and microbes in the environment. They also are able to stretch so you can move your fingers and arms into many positions.

Understanding your test results Epithelial cells naturally slough off from your body. It’s normal to have one to five squamous epithelial cells per high power field (HPF) in your urine. Having a moderate number or many cells may indicate: a yeast or urinary tract infection (UTI)

From the data, it was calculated that the average life span of stromal cells is probably longer than 30 years and of epithelial cells longer than 2 years.

1 : a membranous cellular tissue that covers a free surface or lines a tube or cavity of an animal body and serves especially to enclose and protect the other parts of the body, to produce secretions and excretions, and to function in assimilation.

Function. The transitional epithelium cells stretch readily in order to accommodate fluctuation of volume of the liquid in an organ (the distal part of the urethra becomes non-keratinized stratified squamous epithelium in females; the part that lines the bottom of the tissue is called the basement membrane).

Transitional epithelium is a stratified tissue which can be stretched laterally when forced to expand. Most of the other epithelial layers either tear or get deformed when they are stretched laterally. This ability of expansion makes transition epithelium unique compared to other epithelial types.

Transitional cells are in your urinary system. It’s the part of your body that includes the kidneys, the bladder and the tubes that connect them. These cells are able to change shape and stretch without breaking and are found throughout your urinary tract.

Simple Columnar Epithelium (indicated in the black box) lining the stomach. Many layers of cells the flatted when the tissue is stretched. Look like stratified squamous epi. Transitional epithelium (400x) the light blue bracket indicates the transitional epithelium when the bladder is distended (full).

This epithelium is found lining the urinary bladder, ureters and urethra, as well as in the ducts of the prostrate gland.

Function. The main role of goblet cells is to secrete mucus in order to protect the mucous membranes where they are found. Goblet cells accomplish this by secreting mucins, large glycoproteins formed mostly by carbohydrates.

Stratified epithelia contain two or more layers of cells. The function of this type of epithelium is mostly protective – the higher the number of layers, the more protective it is. It is good at withstanding abrasion. This type of epithelium is constantly renewing itself.

There are four types of stratified epithelium: stratified squamous epithelium, stratified cuboidal epithelium, stratified columnar epithelium and transitional epithelium. This is characterized by numerous cell layers, with the outermost layer consisting of very flat cells.

Stratified squamous epithelia are found in nearly every organ system where the body comes into close contact with the outside environment – from the skin to the respiratory, digestive, excretory and reproductive systems.

Protection. Because stratified tissue consists of several layers of cells, they offer better protection from external threats, such as the filtering in of harmful toxins. Epidermis, or external skin, is an example of stratified tissue.