Difference Between Squamous Epithelium and Columnar Epithelium

The key difference between squamous epithelium and columnar epithelium is that the squamous epithelium contains flattened and scale-like cells while the columnar epithelium contains column-shaped cells.

We have four different types of tissues in our body. They are connective tissue, muscular tissue, nervous tissue, and epithelial tissue. Epithelial tissue is important in covering the body, lining the body cavities, and composing the glands. Epithelial tissue lacks blood vessels, but it is innervated in nature. It comprises cell layers tightly connected together. Epithelium fulfils several different functions in our body. It protects our body from radiation, desiccation, toxins, and physical trauma. In the digestive tract, the epithelium facilitates nutrient absorption. Furthermore, it secretes sweat, mucus, enzymes and other products of ducts. Epithelial tissues can be categorized into three basic shapes; squamous, columnar and cuboidal, and based on the number of layers, it can be simple epithelium or stratified epithelium.

CONTENTS

1. Overview and Key Difference
2. What is Squamous Epithelium
3. What is Columnar Epithelium
4. Similarities Between Squamous Epithelium and Columnar Epithelium
5. Side by Side Comparison – Squamous Epithelium vs Columnar Epithelium in Tabular Form
6. Summary

What is Squamous Epithelium?

Squamous epithelium is a type of epithelial tissue that comprises flattened and scale-like cells. Cells are wider than their height. It has two forms; simple squamous epithelium and stratified squamous epithelium. Simple squamous epithelium has a single layer of cells that are flat in shape. It appears as a membrane due to its thin layer. This type of epithelium facilitates passive diffusion. Hence they are located in the walls of capillaries, linings of the pericardium, and the linings of the alveoli of the lungs.

Figure 01: Squamous Epithelium

Furthermore, they aid in filtration and secreting lubricating substances. Stratified squamous epithelium has several layers of flat shaped cells. This type of epithelium lines the oesophagus, mouth, vagina, etc. and helps in the protection against abrasion.

What is Columnar Epithelium?

Columnar epithelium is one of the three types of epithelial tissue. The cells are taller than being wide, and they are column-shaped. Moreover, there are three types of columnar epithelium such as simple columnar epithelium, stratified columnar epithelium, and pseudostratified columnar epithelium. Simple columnar epithelium has one layer of tall and closely packed cells. They are present in the walls of the stomach and small intestine for the secretory and absorptive functions respectively.

Figure 02: Columnar Epithelium

Stratified columnar epithelium has few layers of taller cells. It is a rare type of epithelial tissue. Pseudostratified columnar epithelium has a single cell layer that misleads by showing the presence of few layers in cross-section. Cells have different heights. Some cells have hair like extensions on them.

What are the Similarities Between Squamous Epithelium and Columnar Epithelium?

• Squamous Epithelium and Columnar Epithelium are types of epithelial tissues.
• Both types have simple and stratified epithelial tissues.
• They involve important functions in our body.

What is the Difference Between Squamous Epithelium and Columnar Epithelium?

The cells are wider in squamous epithelium. On the other hand, cells are taller in the columnar epithelium. Simple squamous and stratified squamous are the two types of squamous epithelium. Simple columnar, stratified columnar and pseudostratified columnar are the three types of columnar epithelium. The below infographic shows the difference between squamous epithelium and columnar epithelium in tabular form.

Summary – Squamous Epithelium vs Columnar Epithelium

Squamous and columnar epithelium are two types of epithelial tissues. Squamous epithelium has cells that are wider than they are tall. Columnar epithelium has cells taller than they are wide. Squamous epithelium has two types while columnar epithelium has three types. This is the difference between squamous epithelium and columnar epithelium.

Reference:

1.Boundless. “Boundless Anatomy and Physiology.” Lumen, Open SUNY Textbooks. Available here
2.“Columnar Epithelial Cell.” Literary Merit. Available here

Image Courtesy:

1.”Illu epithelium” (Public Domain) via Commons Wikimedia 
2.”Simple columnar epithelial cells” (CC BY 3.0) via Commons Wikimedia

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