Reticulum (anatomy) on:
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The reticulum is the second chamber in the four-chamber
The internal mucosa has a honeycomb shape. When looking at the reticulum with ultrasonography it is a crescent-shaped structure with a smooth contour. raun, U., and D. Jacquat. 2011. Ultrasonography of the reticulum in 30 healthy Saanen goats. Acta Veterinaria Scandinavica 53:19/ref> The reticulum is adjacent to the diaphragm, lungs, abomasum, rumen and liver. The heights of the reticular crests and depth of the structures vary across ruminant animal species.[Clauss, M., Hofmann, R. R., Streich, W. J., Fickel, J., and Hummel, J. 2009. Convergence in the macroscopic anatomy of the reticulum in wild ruminant species of different feeding types and a new resulting hypothesis on reticular function. Journal of Zoology. 281:26-38.] Grazing (behaviour), Grazing ruminants have higher crests than Browsing (herbivory), browsers. However, general reticulum size is fairly constant across ruminants of differing body size and feeding type.
In a mature cow, the reticulum can hold around 5 gallons (20 litres) of liquid. The rumen and reticulum are very close in structure and function and can be considered as one organ. They are separated only by a muscular fold of tissue.
In immature ruminants, a reticular groove is formed by the muscular fold of the reticulum. This allows milk to pass by the reticulorumen straight into the abomasum.
alimentary canal
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. ...
of a ruminant
Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...
mammal. Anatomically it is the smaller portion of the reticulorumen
The reticulorumen (; ) represents the first two chambers in the alimentary canal of ruminant animals. It is composed of the rumen and reticulum. The reticulum differs from the rumen with regard to the texture of its lining. The rumen wall is cover ...
along with the rumen
The rumen, also known as a paunch, is the largest stomach compartment in ruminants. The rumen and the reticulum make up the reticulorumen in ruminant animals. The diverse microbial communities in the rumen allows it to serve as the primary si ...
. Together these two compartments make up 84% of the volume of the total stomach.
The reticulum is colloquially referred to as the ''honeycomb'', ''bonnet, or ''kings-hood''. When cleaned and used for food, it is called "tripe
Tripe is a type of edible lining from the stomachs of various farm animals. Most tripe is from cattle and sheep.
Types
Beef
Beef tripe is made from the muscle wall (the interior mucosal lining is removed) of a cow's stomach chambers: th ...
".
Heavy or dense feed and foreign objects, such as pieces of metal will settle here. It is for this reason that it was nicknamed in Irish as () or ('stomach of farthings'). It is the site of hardware disease in cattle, and because of the proximity to the heart this disease can be life-threatening.
Anatomy
The internal mucosa has a honeycomb shape. When looking at the reticulum with ultrasonography it is a crescent-shaped structure with a smooth contour. raun, U., and D. Jacquat. 2011. Ultrasonography of the reticulum in 30 healthy Saanen goats. Acta Veterinaria Scandinavica 53:19/ref> The reticulum is adjacent to the diaphragm, lungs, abomasum, rumen and liver. The heights of the reticular crests and depth of the structures vary across ruminant animal species.[Clauss, M., Hofmann, R. R., Streich, W. J., Fickel, J., and Hummel, J. 2009. Convergence in the macroscopic anatomy of the reticulum in wild ruminant species of different feeding types and a new resulting hypothesis on reticular function. Journal of Zoology. 281:26-38.] Grazing (behaviour), Grazing ruminants have higher crests than Browsing (herbivory), browsers. However, general reticulum size is fairly constant across ruminants of differing body size and feeding type.
In a mature cow, the reticulum can hold around 5 gallons (20 litres) of liquid. The rumen and reticulum are very close in structure and function and can be considered as one organ. They are separated only by a muscular fold of tissue.
In immature ruminants, a reticular groove is formed by the muscular fold of the reticulum. This allows milk to pass by the reticulorumen straight into the abomasum.
Role in digestion
The fluid contents of the reticulum play a role in particle separation. This is true both in domestic and wild ruminants. The separation takes place through biphasic contractions. In the first contraction, there is sending large particles back into the rumen while the reticulo-omasal orifice allows the passage of finer particles. In the second contraction, the reticulum contracts completely so the empty reticulum can refill with contents from the rumen. These contents are then sorted in the next biphasic contraction. The contractions occur in regular intervals. High density particles may settle into the honeycomb structures and can be found after death. It is during the contractions of the reticulum that sharp objects can penetrate the wall and make their way to the heart. Some ruminants, such as goats, also have monophasic contractions in addition to the biphasic contractions.See also
* Methanogens in digestive tract of ruminantsReferences
{{Authority control Mammal anatomy Digestive system Ruminants