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mucus

Wednesday 28 December 2016

Adj. mucous

WKP

Definition: In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes.

Mucous fluid is rich in glycoproteins and water. It is typically produced from cells found in mucous glands.

Mucous fluid may also originate from mixed glands, which contain both serous and mucous cells.

It is a viscous colloid containing antiseptic enzymes (such as lysozymes), immunoglobulins, inorganic salts, proteins such as lactoferrin, and glycoproteins known as mucins that are produced by goblet cells in the mucous membranes and submucosal glands.

This mucus serves to protect epithelial cells (that line the tubes) in the respiratory, gastrointestinal, urogenital, visual, and auditory systems; the epidermis in amphibians; and the gills in fish.

A major function of this mucus is to protect against infectious agents such as fungi, bacteria and viruses. The average human nose produces about a liter of mucus per day. Most of the mucus produced is in the gastrointestinal tract.

Bony fish, hagfish, snails, slugs, and some other invertebrates also produce external mucus. In addition to serving a protective function against infectious agents, such mucus provides protection against toxins produced by predators, can facilitate movement and may play a role in communication.

Localization

- sinonasal mucus
- digestive mucus
- bronchial mucus
- rhinopharyngeal mucus
- cervical mucus

Mucins

The mucins (MUCs ) represent a heterogeneous group of high-glycosylated and high-molecular-weight glycoproteins encoded by several mucin genes clustered on chromosome 11p15.5, basically consisting of a common proteic backbone (apomucin) linked to oligosaccharides.

They are the major structural component of mucus and are widely expressed by most human epithelial tissues.

Pathology of the mucus

- mucus hypersecretion
- mucus hyperviscosity

  • cystic fibrosis / mucoviscidosis

See also

- saliva