What is Stratified Squamous Epithelium?
Epithelial tissues are a group of compactly packed cells with very little intercellular matrices. It is a type of simple epithelial tissue based on differences in structural modifications. Epithelial tissue is the most widespread tissue in the human body that covers all the external and internal surfaces of our body.
Structure
Squamous epithelium is made up of a single layer of flattened cells that have irregular boundaries. These single layers of cells lie upon each other to form a stratified squamous epithelium.
The stratified epithelia thus consists of two or more layers of cells. It has a basal membrane that is made up of columnar or cuboidal cells with squamous epithelium stacked upon them.
Types of Stratified Squamous Epithelium
The stratified squamous epithelium can be of two types – keratinising and non-keratinising. Let us discuss them in detail.
- Keratinised Squamous Epithelium
As the name suggests, this type of epithelium has a layer of keratin protein deposited on its surface. This deposition makes the keratinised squamous epithelium layer impermeable and dry. It protects against mechanical and chemical damage and prevents water loss.
It is usually 8-10 layers thick and it is difficult to see the basal layer in such types of epithelium. The cells on the surface are usually flat and are no longer alive, they do not have any nuclei or cell organelles. These cells start out as columnar or cuboidal cells in the basal layer, divide by mitosis and emerge to the surface and become flattened. Examples of keratinised squamous epithelium include: the skin, palms, and the oral mucosal membrane.
- Non-keratinised Squamous Epithelium
Non-keratinised squamous epithelium are found in places that have to be kept moist and prevent drying out. The oesophagus is the prime example of non-keratinised squamous epithelium. Other examples include – conjunctiva of the eye, vagina, rectum and pharynx.
Function
The primary function of the stratified squamous epithelium is to provide protection against the outer environment. It also protects against abrasion by constantly shedding off the surface membrane cells and emergence of new cells from the basal membrane.
This sums up the stratified squamous epithelium. Stay connected with us at BYJU’S for more updates on NEET.
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Frequently Asked Questions
What is stratified squamous epithelium and where is it found?
The stratified squamous epithelium is a protective tissue that is found in the outer layer of the skin. It protects our skin against abrasion and water loss.
Why is skin stratified squamous epithelium?
Our skin is the outermost layer of the body that is exposed to various outside elements. This layer is keratinised and thus protects against any mechanical or physical damage and also prevents water loss.
Does stratified squamous epithelium have cilia?
No, stratified squamous epithelium does not have cilia.
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