Histology - Esophagus
Esophagus
Long, muscular tube delivers food from the pharynx to the stomach.
- Mucosa layer
- Comprises stratified squamous epithelium; layers of flattened cells provide protection against physical and chemical damage from the foods, liquids, and salivary juices traveling to the stomach.
- Muscularis mucosae is also visible in our sample.
- Submucosal layer
- Submucosal glands
- Glands of the submucosal and mucosal layers produce protective and lubricating mucous, which contributes to the protective barrier.
- Submucosa and mucosa form longitudinal folds in the relaxed esophagus; these folds expand to accommodate foods and liquids during swallowing.
- Muscularis externa layer
- The upper 1/3rd comprises skeletal muscle fibers in both the circular and longitudinal layers;
- The middle 1/3rd comprises a circular layer of skeletal muscle and a longitudinal layer of smooth muscle;
- Both layers of the lower 1/3rd, which opens to the stomach, contains smooth muscle fibers.
- The outermost layer of the esophagus is adventitia; once the esophagus passes through the diaphragm, and is no longer anchored to the body wall, it becomes serosa.