Mucous membranes are thin layers of tissue that line various cavities and surfaces in the body, such as the nose, mouth, throat, and digestive tract. They produce a thick fluid called mucus, which helps to keep these areas moist and protects them from pathogens and irritants. Mucous membranes play a crucial role in the body's immune response. These membranes are made up of epithelial cells and connective tissue. They serve important functions, including trapping dust and microbes in the respiratory system and aiding in the absorption of nutrients in the intestines. Overall, mucous membranes are essential for maintaining health and proper bodily functions.