I think that it is a smooth tissue to ease the passage of air, so I think that it has not a specific function for the respiratory system. However, this is not an answer from an expert. Since answers can be afterwards edited, please wait for another response.
Wikipedia says the following about mucous membrane >
Structure of the Mucous Membrane -The epithelium covering the mucous membrane differs in its character according to the functions of the part of the nose in which it is found. In the respiratory region it is columnar and ciliated. Interspersed among the columnar cells are goblet or mucin cells, while between their bases are found smaller pyramidal cells. Beneath the epithelium and its basement membrane is a fibrous layer infiltrated with lymph corpuscles, so as to form in many parts a diffuse adenoid tissue, and under this a nearly continuous layer of small and larger glands, some mucous and some serous, the ducts of which open upon the surface. In the olfactory region the mucous membrane is yellowish in color and the epithelial cells are columnar and non-ciliated; they are of two kinds, supporting cells and olfactory cells. The supporting cells contain oval nuclei, which are situated in the deeper parts of the cells and constitute the zone of oval nuclei; the superficial part of each cell is columnar, and contains granules of yellow pigment, while its deep part is prolonged as a delicate process which ramifies and communicates with similar processes from neighboring cells, so as to form a net-work in the mucous membrane. Lying between the deep processes of the supporting cells are a number of bipolar nerve cells, the olfactory cells, each consisting of a small amount of granular protoplasm with a large spherical nucleus, and possessing two processes-a superficial one which runs between the columnar epithelial cells, and projects on the surface of the mucous membrane as a fine, hair-like process, the olfactory hair; the other or deep process runs inward, is frequently beaded, and is continued as the axon of an olfactory nerve fiber. Beneath the epithelium, and extending through the thickness of the mucous membrane, is a layer of tubular, often branched, glands, the glands of Bowman, identical in structure with serous glands. The epithelial cells of the nose, fauces and respiratory passages play an important role in the maintenance of an equable temperature, by the moisture with which they keep the surface always slightly lubricated.
As you see, the mucous membrane has many and important functions.
The types of membranes lining cavities that communicate with the exterior of the body are mucous membranes. These membranes are found in areas such as the respiratory, digestive, urinary, and reproductive tracts, and they secrete mucus to protect and lubricate the tissues.
believe it or not, mucous membranes secrete mucous. It helps protect the respiratory system (or whichever system the mucous membrane you're referring to is in).
These membranes are called mucous membranes or mucosa. They secrete mucus to protect the lining and provide lubrication for various body cavities that are exposed to external environments, such as the respiratory, digestive, and reproductive systems.
The membranes that line body cavities open to the exterior are called mucous membranes. They are made up of epithelial tissue and are found in areas like the respiratory, digestive, and reproductive tracts. Mucous membranes help protect the body by secreting mucus and trapping pathogens.
esophagus Every system that has an outside opening produces mucous. This includes the respiratory, urinary, digestive and urogenital systems. Also the lining of the eye produces mucous. This substance keeps the membranes moist and prevents them from drying out.
The types of membranes lining cavities that communicate with the exterior of the body are mucous membranes. These membranes are found in areas such as the respiratory, digestive, urinary, and reproductive tracts, and they secrete mucus to protect and lubricate the tissues.
believe it or not, mucous membranes secrete mucous. It helps protect the respiratory system (or whichever system the mucous membrane you're referring to is in).
Goblet cells in mucous membranes secrete a water-based protein solution called mucin. This solution helps to lubricate and protect the mucous membranes lining various body surfaces, such as the respiratory and digestive tracts.
Mucous membranes
These membranes are called mucous membranes or mucosa. They secrete mucus to protect the lining and provide lubrication for various body cavities that are exposed to external environments, such as the respiratory, digestive, and reproductive systems.
Common cold
The respiratory system, gastrointestinal tract, and the urinary system (including the bladder) are lined with mucous membranes. These membranes help protect the organs from pathogens and maintain necessary moisture levels for their functions.
true
The lining of the mouth is an example of a mucous membrane. Mucous membranes line various cavities in the body and produce mucus to protect and lubricate the underlying tissues.
mucous membranes of the respiratory tract
Mucous membranes line the digestive and respiratory tracts.
esophagus Every system that has an outside opening produces mucous. This includes the respiratory, urinary, digestive and urogenital systems. Also the lining of the eye produces mucous. This substance keeps the membranes moist and prevents them from drying out.