We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is Epithelial Tissue?

Mary McMahon
Updated Mar 03, 2024
Our promise to you
The Health Board is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At The Health Board, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Epithelial tissue is one of the four major tissue types in the body, acting as an interface between the body and the rest of the world. Your skin is composed of this tissue, and it also lines your body cavities and major organs. There are several different types of epithelial tissue, which form to fulfill specific needs and functions. This tissue, known collectively as the epithelium, can filter, absorb, and diffuse various substances, and it is also involved in sensory perception and bodily secretions.

The other main tissue types are muscle tissue, nervous tissue, and connective tissue. Epithelial tissue is distinguished by several features. The first is the fact that cells in this tissue are extremely tightly packed, with minimal intracellular spaces between them. It is also separated from the underlying tissue by the basement membrane, a layer of material that is partly formed by the epithelial tissue, and partly by the underlying tissue. The cells are also attached to one another, and they are polarized, with an “up” side and a “down” side which connects to the basement membrane or underlying epithelial cells.

Epithelial tissue can be divided into simple tissue, which consists of a single layer of cells, and stratified epithelium, which involves two or more layers of cells. Within these basic categories, the tissue can be further classified by the shape of the cells. Squamous epithelial tissue is composed of a series of flattened cells that look like cobblestones, while cuboidal epithelium has roughly cube-shaped cells, sort of like stacked sugar cubes. Columnar tissue has cells in the shapes of columns, and it may be topped with very fine hairs known as cilia for sensory perception in locations like the lining of the nose.

One of the primary functions of epithelial tissue is protection. The epithelium is like a flexible, adaptive armor plating for the body. New cells are constantly growing to replenish older ones, and in some cases, like the skin, a layer of keratinized cells acts as an additional layer of protection. As the body's first line of defense, the epithelium is also very sensitive to potential threats.

Inside the body, the epithelium is sometimes referred to as the endothelium. Epithelial cells all over the body are vulnerable to damage from a variety of sources, and they can potentially develop cancers and abnormalities, because they are designed to replicate quickly. If an error in duplication arises, it can spread rapidly to the neighboring cells, resulting in a tumor or cancer.

The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a The Health Board researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments

By anon299124 — On Oct 23, 2012

What are the five main characteristics of cancerous tissues?

By anon147528 — On Jan 29, 2011

Why do certain tissues have a single layer, while others are stratified?

By anon125236 — On Nov 08, 2010

what are resources that the bloodstream brings to the epithelial tissue for it to work properly?

By anon121644 — On Oct 25, 2010

The function of epithelial tissue is protection and secretion.

By anon118205 — On Oct 13, 2010

how is the structure of epithelial tissue related to its function? every time i search i only get answers on ciliated epithelial tissue.

By cmsmith10 — On Jul 11, 2010

Epithelial tissue is also very helpful in the field of forensic science. DNA can be pulled from the epithelial and is very useful in eliminating or finding suspects in certain crimes.

By frankjoseph — On Nov 05, 2009

Dust is mostly comprised of epithelials.

Mary McMahon

Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.