Final answer:
Mucous membranes are inserted at the epithelial tissue lining body surfaces and openings, providing a barrier against pathogens. They are found in the respiratory, GI, urinary, and reproductive tracts, and contain cilia which help expel trapped pathogens.
Step-by-step explanation:
The proper insertion point for tissue building mucous membranes is at the epithelial tissue that lines inner body surfaces and body openings which produce mucus. These membranes are essential as they provide a mechanical barrier to pathogens, especially at body openings such as the eyes, nose, mouth, urethra, and anus. They line various tracts in the body including the respiratory, gastrointestinal (GI), urinary, and reproductive tracts.
Mucous membranes are made up of epithelial tissue, the lamina propria which is a connective tissue layer, and in some cases, a thin layer of muscle known as the muscularis mucosae. They not only secrete mucus but also possess hair-like cilia which help sweep mucus and trapped pathogens towards body openings for expulsion. This can be observed during actions like sneezing, coughing or even when clearing the throat or blowing the nose.