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Develops from the distal part of the foregut.
An organ with 1200-1500 cc volume, but has a capacity of greater than 3000 cc.
Joins the esophagus and extends to the right of the midline where it connects to the duodenum.
The right sided concavity is referred to as the lesser curvature while the convexity of the outer curve is the greater curvature.
The incisura angularis is an angle along the lesser curve and marks the point at which the stomach narrows prior to its junction with the duodenum.
Covered by the peritoneum.
Divided into 5 anatomic regions: the cardia, fundus, body, antrum and pyloric sphincter.
The cardia of the stomach is the narrow conical part of the stomach immediately distal to the gastroesophageal junction.
The fundus of the stomach refers to the dome shaped portion of the proximal stomach that extends superolateral to the gastroesophageal junction.
The body or corpus of the stomach comprises the remainder of the stomach proximal to the incisura angularis.
The stomach distal to the incisura angularis is the antrum.
The pyloric sphincter demarcates the stomach from the duodenum.
The wall consists of a mucosa, submucosal, muscular is propria and serosa.
Abundant blood supply including the right and left gastric arteries, right and left gastroepiploic arteries and the sort gastric artery plus numerous minor and collateral sources.
Secretes 2-3 L/d of fluid depending on a fed or fasted state.
It carries an additional 500cc-1500cc of secreted saliva daily.
As saliva, gastric secretions are stimulated by the cephalic stage of eating.
Loss of gastric secretions can lead to dehydration, hypochloremic metabolic alkalosis.
Large gastric folds seen in edematous states, Menetrier’s disease, Zollinger-Ellison syndrome, Heliocobacter pylori gastritis,infiltrative diseases such as sarcoidosis, eosinophilic gastroenteritis,, or gastric carcinoma.
The stomach has a priority to destroy the bacteria and viruses using its highly acidic environment but also has a duty to protect its own lining from its acid.
The stomach protects itself by secreting mucin and bicarbonate via its mucous cells, and also by having a rapid cell turn-over.
There are four types of cells in the stomach:
Parietal cells: Produce hydrochloric acid and intrinsic factor.
Gastric chief cells: Produce pepsinogen.
Chief cells are mainly found in the body of stomach, which is the middle or superior anatomic portion of the stomach.
Mucous neck and pit cells: Produce mucin and bicarbonate to create a “neutral zone” to protect the stomach lining from the acid or irritants in the stomach chyme.
G cells: Produce the hormone gastrin in response to distention of the stomach mucosa or protein, and stimulate parietal cells production of their secretion.
G cells are located in the antrum of the stomach, which is the most inferior region of the stomach.
The stomach is half empty after an average of 1.2 hours.
After four or five hours the stomach has emptied.