The Physiology of Gastric Secretions
January 19th 2010 12:38
The Gastrointestinal Tract and the Accessory Organs for Digestion
The gastrointestinal tract or the alimentary tract is divided into two main parts: the upper and the lower. The upper part includes the mouth, the pharynx, the esophagus, and the stomach. The lower part is composed of the small and the large intestine, together with the anus.
Throughout the tract, we see many specialized glands. The functions of these secretory glands are: (1) for digestion of food through enzymes secreted anywhere from the mouth down to the distal end of the ileum; and (2) for lubrication and protection of the tract as being carried out by mucus secreted from mouth to anus.
Most digestive secretions are formed only in response to food in the alimentary canal. The quantity however has to be enough to facilitate proper digestion and prevent structural injuries to the walls. The types of enzymes secreted depend on where the gland is located, as well as on the type of food presented into the lumen.
The accessory organs include the liver, the gall bladder, and the pancreas. The liver secretes bile that emulsifies fats. The gall bladder serves as reservoir for bile, in turn concentrating the substance before it is secreted into the duodenum of the small intestine. The pancreas in turn secretes bicarbonates, trypsin, lipase, and amylase necessary for intestinal digesti
The gastrointestinal tract or the alimentary tract is divided into two main parts: the upper and the lower. The upper part includes the mouth, the pharynx, the esophagus, and the stomach. The lower part is composed of the small and the large intestine, together with the anus.
Throughout the tract, we see many specialized glands. The functions of these secretory glands are: (1) for digestion of food through enzymes secreted anywhere from the mouth down to the distal end of the ileum; and (2) for lubrication and protection of the tract as being carried out by mucus secreted from mouth to anus.
The accessory organs include the liver, the gall bladder, and the pancreas. The liver secretes bile that emulsifies fats. The gall bladder serves as reservoir for bile, in turn concentrating the substance before it is secreted into the duodenum of the small intestine. The pancreas in turn secretes bicarbonates, trypsin, lipase, and amylase necessary for intestinal digesti
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