Difference Between Esophageal and Gastric Epithelium

The key difference between esophageal and gastric epithelium is that esophageal epithelium is a non-keratinized stratified squamous epithelium while gastric epithelium is a simple columnar epithelium.

Epithelium is one of the four basic types of animal tissues. It forms the covering of all body surfaces and lines the hollow organs and body cavities. Esophagus is a part of the alimentary canal and connects the throat to the stomach. It is lined by a stratified squamous epithelium. Gastric mucosa is the innermost layer of the stomach. The surface of gastric mucosa is lined by a simple columnar epithelium. Therefore, gastric epithelium is a single layer of columnar cells.

CONTENTS

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

What is Esophageal Epithelium?

Esophagus is a muscular tube that connects the throat and stomach. It is a simple tube and a part of our alimentary canal. Esophagus is lined by epithelial tissue. Esophagus epithelium is a stratified squamous epithelium. There are submucosal mucous glands scattered in the esophagus epithelium. They provide lubrication to the esophagus. Generally, esophagus epithelium is not exposed to dryness or to abrasion. Hence, it is non-keratinized.

Esophageal epithelium provides protection against foreign antigens. The surface of the epithelium is deeply indented by connective tissue papillae. Moreover, breaches in the esophageal epithelium can give rise to esophageal ulcers. Near the cardiac orifice or at the junction of the stomach, esophageal epithelium, which is a stratified squamous epithelium, takes a transition to simple columnar epithelium.

What is Gastric Epithelium?

Gastric mucosa is the innermost layer of the stomach. The surface of the mucous membrane is covered by the gastric epithelium. Gastric epithelium is a single layer of columnar epithelium, so it is a simple columnar epithelium. Beneath the gastric epithelium, there are closely packed tubular glands. The gastric epithelium is indented into numerous short gastric pits or tiny invaginations. These numerous tiny invaginations appear as millions of holes in the gastric lining. They are also connected to the various gastric glands of the stomach and allow the glandular products to be delivered into the stomach lumen. There are approximately 90 to 100 gastric pits per square millimetre of gastric epithelium.

The gastric mucosa is always covered by a layer of mucous. The gastric epithelium secretes an alkaline, highly viscous mucous in order to lubricate food and facilitate the movement of food along the GI tract.

What are the Similarities Between Esophageal and Gastric Epithelium?

• Esophageal and gastric epithelia are two types of epithelia that line internal surfaces in the parts of the alimentary tract.
• Esophageal epithelium takes a transition into simple columnar epithelium at the junction of the stomach.
• The transition of esophageal epithelium into gastric epithelium is visible as a zig-zag line.
• There are numerous mucous glands in both epithelia.

What is the Difference Between Esophageal and Gastric Epithelium?

Esophageal epithelium is a stratified squamous epithelium of around three layers of squamous cells while gastric epithelium is a single layer of columnar cells. So, this is the key difference between esophageal and gastric epithelium.

Below infographic shows more details of the difference between esophageal and gastric epithelium.

Summary – Esophageal vs Gastric Epithelium

Esophageal epithelium is a non-keratinized stratified squamous epithelium. In contrast, gastric epithelium or stomach epithelium is a simple columnar epithelium. Therefore, there are multiple cell layers in the esophageal epithelium while there is a single cell layer in the gastric epithelium. Thus, this is the key difference between esophageal and gastric epithelium.

Reference:

1. Kuo, Braden, and Daniela Urma. “Esophagus – Anatomy And Development”. Nature.Com, 2020, Available here.
2. “Human Digestive System – Gastric Mucosa”. Encyclopedia Britannica, 2020, Available here.

Image Courtesy:

1. “Esophageal adenocarcinoma – intermed mag” By Nephron – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Normal gastric mucosa intermed mag” By Nephron – Own work (CC BY-SA 3.0) via Commons Wikimedia