Esophagus wall. Colored light micrograph of a transverse section through the human esophagus, which passes food from the mouth to the stomach. The esophagus lumen is lined by a layer of stratified squamous epithelium. This protects underlying tissue and enables the passage of solid material by the lubricant action of its glandular secretion. Next is a supporting layer of connective tissue, the lamina propria, which is rich in elastin fibers. A mucus duct (upper center) can be seen running down these layers to join the submucosa, which contains mucous glands for lubricating the esophagus as food passes through it.