Oesophagus. Light micrograph of a section through a whole oesophagus. The oesophagus passes food from the mouth to the stomach. The oesophagus lumen (white, centre) is lined by a layer of stratified squamous epithelium (pink). This protects underlying tissue and enables the passage of solid material by the lubricant action of its glandular secretion. Surrounding this is a supporting layer of connective tissue, the lamina propria, which is rich in elastin fibres (blue). Outside of this is are layers of circular and longitudinal muscle (orange). Magnification: x1.5 when printed at 10 centimetres wide