Final answer:
The oral mucous membrane is composed of the epithelium and the lamina propria, with an additional thin layer of smooth muscle known as the muscularis mucosae. The epithelium produces mucus and protects against stress, while the lamina propria supports and nourishes the epithelial layer.
Step-by-step explanation:
The oral mucous membrane, also known as the oral mucosa, is composed of two main layers: the epithelium and the lamina propria. The epithelium is the outermost layer in direct contact with the ingested food. It includes several types of cells, with the primary ones being non-keratinized, stratified squamous epithelial cells that protect against mechanical stress and produce mucus to moisturize and lubricate the oral cavity.
The lamina propria is a layer of connective tissue just beneath the epithelium. It provides support and nourishment to the epithelial layer and is similar to the dermis of the skin. Additionally, this layer often contains a thin layer of smooth muscle called the muscularis mucosae, which provides structural support and facilitates local movement of the mucosa.
Mucous membranes are found lining various body cavities and tracts that open to the external environment, including the digestive, respiratory, excretory, and reproductive systems. In the mouth, the mucous membrane is particularly important as it plays a critical role in the initial stages of digestion by helping to moisten and begin the breakdown of food.