The stomach is a vital organ for digestion. It is located in the superior aspect of the abdomen protected by the rib cage. Its overall structure can be thought of as 'J shape' with lesser an greater curvature.
The cardia is the area surrounding the superior opening to the stomach, it surrounds the opening to the oesophagus.
The fundus is the rounded portion of the stomach that is in the most superior aspect.
The body is the main portion of the stomach inferior to the fundus.
The pylorus is the most inferior portion of the stomach connecting it to the duodenum.
The stomach has a greater and lesser curvature. The greater curvature is more lateral curve, the lesser being the more medial.
There are two sphincters in the stomach, the first being inferior oesophageal sphincter (the greater being located in the pharynx). The inferior oesophageal sphincter is situated immediately inferior to the oesophageal hiatus -the opening in the diaphragm that allows the oesophagus to pass.
The pyloric sphincter is located between the pylorus and the duodenum regulating the movement of the chyme out of the stomach through into the duodenum. Peristalsis (the rhythmic contracting of the smooth muscle i the stomach wall churns the chyme. The pylorus offers a pressure barrier which helps regulate the movement of the chyme through into the duodenum, for successful transition the intragastric pressure in the stomach must exceed that i the pylorus for chyme to be expelled.
Covering the organs of the gastrointestinal tract is peritoneum, this is a thin membrane, there are two componants in the GI tract of landmark and physiological importance.
The Greater Omentum
The greater omentum is attached to the greater curvature (more lateral aspect) of the stomach descends inferior over the transverse colon before folding back on itself heading superior and posterior connecting with the posterior abdomen wall. The greater omentum provides a place for macrophages to gather providing immune function should the GI become infected with pathogens.
The Lesser Omentum
The lesser omentum is a smaller membrane that leaves from the lesser curvature (the more medial aspect of the stomach).
Blood is pumped to the stomach via the coeliac trunk.
The stomach receives innervation from the autonomic nervous system, parasympathetic and sympathetic.
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