Stomach, duodenum, pancreas Flashcards
Cardia
First region of stomach which lies just beneath the lower end of the gastroesophageal sphincter. The masticated food, coming from mouth, enters the cardia while leaving the esophagus or food gut through the lower esophageal sphincter.
Fundus
In the anatomy of stomach, it is the uppermost portion, forming the upper curvature of the organ. When chemical digestion takes place in the stomach, stomach gases are produced. These gases are accumulated in the fundus. Moreover, it can also store undigested food for about an hour.
Corpus
The word ‘corpus’ has been derived from Latin, and refers to the body or major part of something. This is the main region of the stomach which lies in the center of the organ. This is where the chemical digestion of food takes place. Enzymes and acidic secretions assist in the digestion of food, especially the protein constituents.
Pylorus
The pylorus connects the stomach to the small intestine. This is where the digested food collects before it enters the small intestine through the pyloric sphincter. With the facilitation of this lowermost section of stomach, the churned and partly digested food is emptied into the small intestine for further digestion and absorption.
Layers of the stomach
Gastric Mucosa (outermost layer)
Submucosa (the layer coming next to mucosa)
Muscularis Externa (third layer of stomach wall, adjacent to submucosa)
Serosa (innermost epithelial layer)
Gastric mucosa
The mucus secreting layer that lines the interior of the stomach. It contains the gastric pits and glands and has a soft, smooth and velvety surface. The presence of the ducts of gastric glands renders its inner surface a honeycomb appearance.
Submucosa
A layer of loose connective tissues that provides mechanical support and connects mucosa to the smooth muscle layer.
Muscular Externa
Lying beneath the submucosa, this layer of stomach can be further divided into three layers, which are: outer longitudinal layer, middle circular layer and inner oblique layer. Plays a role in churning and helps to form the pyloric sphincter.
Serosa
Serosa or serous membrane is made up of two layers of epithelial cells, called visceral membrane and parietal layer. A lubricating fluid, produced by serosa, is used to decrease friction caused by different layers of muscles moving against each other.
Parietal Cells
Also known as oxyntic cells. They are found in the epithelium of stomach. The parietal cells are responsible for the secretion of HCL and intrinsic factor. These cells are only in the fundic region of the stomach.
Foveolar Cells
Located in the fundus, cardiac and pyloric regions of the stomach, these are the mucus secreting cells. The mucus forms a gel-like layer to the interior of the stomach which serves as a protection against the corrosive effect of gastric acid.
Enteroendocrine Cells
Like faveolar cells, enteroendocrine cells are also found in three different regions of the stomach (cardiac, pyloric and fundus). They secrete peptides or gastrointestinal hormones. Playing the role of chemoreceptors, the enteroendocrine cells cause the initiation of digestive processes. They have also been seen as identifying harmful substances in the food and triggering protective responses.
Chief Cells
Gastric chief cells are only in the deep mucosal layer of the fundus. Stimulated by the acidic condition in the stomach they release pepsinogen and gastric lipase, which then carries out the digestion of proteins and fat.
Magenstrasse
The grooves in the stomach along the lesser curvature that is the route food and liquids tend to take in moving toward the pylorus.
Rugae
Rugae are the rides and folds that provide the stomach with increased surface area for nutrient absorption. Mostly along greater curve. When food enters the stomach, these folds stretch outward. This allows the stomach to expand, therefore increasing the volume of the stomach without increasing pressure.
