Stomach

The stomach is the dilated portion of the alimentary & situated in the upper part of the abdomen, extending from beneath the left costal margin into the epigastric and umbilical regions.

      Much of the stomach lies under cover of the lower ribs.

It is roughly J-shaped and has :

1-two openings, the cardiac and pyloric orifices.

2-two curvatures, the greater and lesser curvatures.

3-two surfaces, an anterior and a posterior surface.

The stomach is relatively fixed at both ends but is very mobile in between. It tends to be high and transversely arranged

Its shape undergoes considerable variation in the same person and depends on the volume of its contents, the position of the body, and the phase of respiration.

 Parts of the stomach:-

1.Fundus: This is dome-shaped and projects upward and to the left of the cardiac orifice. It is usually full of gas.

2.Body: This extends from the level of the cardiac orifice to the level of the incisura angularis, (a constant notch in the lower part of the lesser curvature).

3.Pyloric antrum: This extends from the incisura angularis to the pylorus.

4.Pylorus: This is the most tubular part of the stomach. The thick muscular wall is called the pyloric sphincter, and the cavity of the pylorus is the pyloric canal.