Epithelial Tissue

You know that your body is made up of many cells and tissues. Epithelial tissue is one of them. The skin that covers your body is made up of epithelial tissue. Let us know more about this tissue in detail.

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What Is Epithelial Tissue?

Epithelial tissues are animal tissues. The cells that are present in these tissues show all the characteristics of animal cells. The cells are eukaryotic with a nucleus and membrane-bound organelles. Animal cells do not have a cell wall and this is what gives them flexibility. The cells of the tissue can take up different shapes to become specialized and perform specific functions.

And so, epithelial tissues have cells that have different shapes, sizes, and arrangements. Accordingly, they are classified into different types. Epithelial cells can be seen in different parts of the body. They cover the body’s surface and also line the internal body organs and body cavities.

Browse more Topics under Tissues

• Introduction to Tissues
• Meristematic Tissue
• Permanent Tissue
• Epithelial Tissue
• Connective Tissues
• Muscular and Nervous Tissues

Their functions include protection of the underlying tissues, absorption of substances, regulation of chemicals between the tissues and body cavity etc. And they are able to perform such varied functions since they do not have a definite shape

What is the Connection between Blood and Bones? Learn about Connective Tissue here.

Types of Epithelial Tissue

The different types of epithelial tissues are given below. Let us learn a little bit about each type. You will see how their shape adapts according to the functions that they perform.

• Squamous Epithelium – These are thin, flat cells that are closely packed. The squamous epithelial cells line the cavities of the mouth, esophagus, alveoli, and blood vessels. This tissue gives protection against mechanical injury and also blocks the entry of germs. If the squamous epithelium is arranged in many layers, it is a compound squamous tissue called the stratified squamous epithelium. We find these kinds of tissues in the skin and also the lining of the esophagus.
• Cuboidal Epithelium – These cells are cuboidal in shape. They are found in the salivary glands, kidney tubules, sweat glands, etc. Their main function includes absorption, secretion, and excretion. If the cuboidal epithelium is arranged in many layers it forms the stratified cuboidal epithelium. It is found on the inner side of the pancreatic ducts and salivary glands. They mainly help in protection.
• Columnar Epithelium – The columnar epithelium has cells that are pillar-like and column-like. We can find them in the lining of the stomach and intestine. Its functions include absorption and secretion.
• Ciliated Epithelium – When the columnar epithelial tissues have cilia, then they are ciliated epithelium. They are present in the lining of the trachea, kidney tubules, etc. The rhythmic movement of the cilia helps in the movement of material in one direction.
• Glandular Epithelium – These are modified columnar epithelial tissues. They are large cells that present in the tear glands, sweat glands etc. Their main function is secretion.

Learn more about Meristematic Tissue here.

Solved Questions For You

Q: Name the type of epithelium found in the lining of the following organs.

Ans. The names are as follows:

• Lining of the small intestine – Columnar epithelium
• The lining of the kidney tubules – Cuboidal epithelium
• Lining of blood vessels – Squamous epithelium
• Respiratory tract – Ciliated Epithelium