Alkaline mucus is a thick fluid produced by animals which confers tissue protection in an
acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
ic environment, such as in the
stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
.
Properties
Mucus
Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is ...
that serves a protective function against acidic environments generally has a high
viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
, though the thickness and viscosity of the mucus layer can vary due to several factors. For example, alkaline mucus in the stomach increases in thickness when the stomach is distended. The
pH level of the mucus also plays a role in its viscosity, as higher pH levels tend to alter the thickness of the mucus, making it less viscous.
Because of this, invading agents such as ''
Helicobacter pylori
''Helicobacter pylori'', previously known as ''Campylobacter pylori'', is a gram-negative, microaerophilic, spiral (helical) bacterium usually found in the stomach. Its helical shape (from which the genus name, helicobacter, derives) is though ...
'', a bacterium that causes stomach ulcers, can alter the pH of the mucus to make the mucus pliable enough to move through. Exposure to atmospheric air also tends to increase the pH level of alkaline mucus.
In humans
In humans, alkaline mucus is present in several organs and provides protection by way of its alkalinity and high
viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
. Alkaline mucus exists in the human
eye,
stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
,
saliva
Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be ...
, and
cervix
The cervix or cervix uteri (Latin, 'neck of the uterus') is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long (~1 inch) and roughly cylindrical in shape, which changes during ...
.
In the stomach, alkaline mucus is secreted by gastric glands in the
gastric mucosa
The gastric mucosa is the mucous membrane layer of the stomach, which contains the glands and the gastric pits. In humans, it is about 1 mm thick, and its surface is smooth, soft, and velvety. It consists of simple columnar epithelium, lamin ...
of the stomach wall.
["Stomach Histophysiology." ''World of Anatomy and Physiology'', Gale, 2007. ''Science In Context''] Secretion of alkaline mucus is necessary to protect the
mucous membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...
of the stomach from acids released during digestion.
Ulcers can develop as a result of damage caused to the
gastric mucosal barrier
The gastric mucosal barrier is the property of the stomach that allows it to safely contain the gastric acid required for digestion.
If the barrier is broken, as by acetylsalicylic acid (ASA, aspirin) in acid solution, acid diffuses back into the ...
. Duodenal ulcers have been shown to develop in sites that are in direct contact with pepsin and acids. To prevent damage and protect the mucus epithelium, alkaline mucus secretions increase in the digestive system when food is being eaten.
In the cervix, alkaline mucus has been shown to possess
bactericidal
A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics.
However, material surfaces can also have bactericidal properties based solely on their ...
properties to protect the cervix, uterus, peritoneal cavity, and vagina from microbes.
References
{{DEFAULTSORT:Alkaline Mucus
Digestive system