Question

Match each statement to a layer of the wall of the esophagus in the key. Answers may be used more than once. a. mucosa b. submucosa c. muscularis d. serosa Contains a layer of epithelium that lines the lumen

Short answer

The correct answer is: a. Mucosa.

Step-by-step solution

Understanding the layers of the esophageal wall

The esophagus wall has four main layers: 1. Mucosa: The innermost layer, which is in contact with the food bolus passing through the esophagus. It is composed of an epithelium, a lamina propria, and a muscularis mucosae. 2. Submucosa: The layer just outside the mucosa. It contains blood vessels, nerves, and glands that secrete mucus. 3. Muscularis: The muscular coat responsible for the peristaltic movements of the esophagus. It is composed of an inner circular layer and an outer longitudinal layer of smooth muscle cells. 4. Serosa: The outermost connective tissue layer that covers the esophagus. It helps to keep the esophagus in place and attach it to the surrounding structures.

Identifying the layer containing epithelium lining the lumen

Since the statement is about the layer that contains epithelium lining the lumen, we should focus on the layer that is in direct contact with the food bolus passing through the esophagus. The mucosa is the innermost layer, which is in contact with the lumen. It consists of an epithelium that lines the lumen and protects the underlying tissue layers. The correct answer is: a. Mucosa