The stomach (in Greek old στόμαχος) is the portion of the digestive Tract in the shape of pocket, located between the esophagus and the Duodénum. The stomach receives the Aliment S chewed in the mouth and swallowed in the esophagus. The body is in capital form of J , it makes 5 cm in height, contains 0,5 L with vacuum, and can contain up to 4 liters. The stomach is in anatomical connection with the Foie, the Rate, the Pancréas, the diaphragm and the Intestin S. It is located at the top of the mésocôlon (stage known-mésocolique).
The stomach makes it possible to ensure the Digestion by its function Mécanique (mixing) and Chimique, by mixing food with the gastric juices (water, Hydrochloric acid, Enzyme S). For an ideal digestion, pH of the stomach lies between 1,5 (during the night) and 5 (at the beginning of digestion).
The processed product by the stomach is a paste, called chyme which flows in the small intestine.
The duration of digestion in the stomach varies approximately between two and six hours.
Anatomy of the stomachThe stomach is characterized by a form in J and presents an opening in top, the Cardia which allows the junction between the esophagus and the stomach and the other controlled by a Sphincter: the Pylore which allows the exit of the gastric chyme in the duodenum. It is composed of three parts from top to bottom:
- the fundus ,
- the body of the stomach,
- the antrum .
Histology of the stomachThe three parts of the stomach are:
- the fundus,
- the Corps comprises the parietal cells (bordering cells) which synthesize hydrochloric acid (HCl) and the principal cells, pepsinogene.
- the Cave.
Control secretion and mobilityThe stomach comprises:
- the cardia which surrounds the opening of entry,
- the higher pole or fundus or large tuberosity, forms a dome which receives gases contained in food,
- the body is the average portion,
- the cave narrows to form the pylore,
- the pylore which constitutes a rise of chyme towards the duodenum.
Gastric secretions are the fact of the specialized gastric glands which comprise various secreting cells according to their localization in the stomach.
Thus, the glands of the cardia produce mucus rather while those of the body produce mucus, pepsinogene (inactive enzyme which is transformed into pepsin activates), of hydrochloric acid and the gastric hormones. The pylore produces mainly gastrine.
DiseasesThe stomach is the seat many diseases, congenital or acquired:
- Cancer S
- Ulcer S, consecutive with an infection with Helicobacter pylori, a stress or with the anti-inflammatory drug catch.
- reversal of the stomach (in the dogs)
Monogastric animalsThey are animals having only one stomachic pocket. Name defines Herbivores whose stomach is not comparable with that of the ruminants (Mouton S, for example).
At the RuminantThe stomach is composed of four cavities in series:
- the Panse is a large pocket, container of the grass, and whose regurgitation of the contents involves the rumination . It also allows a digestion by bacterial fermentation .
- the bonnet : contain bacteria and protists mutualists who attack the meal rich in cellulose. These micro-organisms release like metabolic by-products of the fatty-acids in the chyme. ;
- the layer : The ruminated matters pass in the layer where them water is extracted. ;
- the petrel : The ruminated matters pass in the petrel to be there digested by the proper enzymes of the ruminant.
Fiu-vro: Mago Simple: Stomach
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