Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to mucus: cervical mucus


the slimy protective secretion of the mucous membranes, consisting mainly of mucin



in animals and man, the secretion of mucous glands. In amphibians mucus is secreted onto the skin, whereas in invertebrates and other vertebrates it is secreted into the internal cavities of many organs, where it coats the mucous membranes.

Mucus is immunologically and bactericidally active. It protects organs and integumentary tissues from mechanical injuries and facilitates the movement of food along the digestive tract. Certain annelids, mollusks, ascidians, and other animals feed on food particles that adhere to the mucus when water is filtered through it.

Chemically, mucus is a complex mixture of glycoproteins, which account for approximately 40 percent of its dry weight. For example, mucus secreted by gastric and intestinal mucous epithelia is an aqueous solution of acid mucopolysaccharides, which are similar or identical to the mucopolysaccharides of connective tissue, neutral glycoproteins, which contain a large quantity of fucose, and acid glycoproteins, which contain sialic acids. Hyaluronic acid is a major constituent of synovia.

Mucus is important in maintaining cellular fluid and ion balances. In mammals it is a constituent of the developing embryo’s connective tissue, although at birth it is found only in the umbilical cord.


Khimiia uglevodov. Moscow, 1967.
Kretovich, V. L. Osnovy biokhimii rastenii, 5th ed. Moscow, 1971.
Schlegel, H. Obshchaia mikrobiologiia. Moscow, 1972. (Translated from German.)



A viscid fluid secreted by mucous glands, consisting of mucin, water, inorganic salts, epithelial cells, and leukocytes, held in suspension.
References in periodicals archive ?
In some people, some foods seem to increase mucus production, either because you are allergic to them or because they contain or produce histamine, a compound which can increase mucus production.
These cells contain a green protein, which, when present in large quantities, turn the mucus into a greenish hue.
The mucus, he concluded, plays a big role in snagging the chameleon's prey.
It's not the best-tasting stuff going down, but I think it's better than suffering from excess mucus all day long.
Smoking also promotes excess mucus production which the damaged cilia cannot remove.
Mucus that |builds up in your nose or throat while you lay down irritates your throat, so pop extra pillows under your head and let gravity do its work.
Take a hot shower or bath as the steam will help loosen the mucus and relieve congestion.
Take | a hot shower or bath as the steam will help loosen the mucus and relieve congestion.
Asthma is characterized by mucus dysfunction, airway hyper-responsiveness and chronic inflammation.
Fahy and his team found that in CF contrary to previous belief inflammation causes new molecular bonds to form within mucus, transforming it from a liquid to an elastic sludge.
Fortunately, we have a built-in, excellent way to get rid of that sticky mucus before it gets loaded with bacteria.
Researchers from the Icahn School of Medicine at Mount Sinai's Immunology Institute foresee a day when mucus could be manufactured and given to sick people to help them fight inflammation and increase immunity.