Which tunic of the stomach is constructed of simple columnar epithelium composed entirely of mucous cells?

Mucosa

Explanation:

The stomach wall can be subdivided into:

• Mucosa - consists of the epithelium that secrete mucus (contains the glands and the gastric pits) and the lamina propria

• Submuscosa - consists of fibrous connective tissue

• Muscularis externa-consists of three layers, responsible for movement and break down of the food

• Serosa-consists of connective tissue continuous with the peritoneum.