The stomach is a hollow organ that lies between the esophagus (food pipe) and duodenum (small intestine). It is an expanded part of the gastrointestinal tract (gut) that plays an important role in the digestion of food. The churning of food and gastric acid secretion breaks down food into smaller particles and simpler compounds for further digestion and subsequent absorption in the small intestine. Certain nutrients and substances are also absorbed in the stomach.
Parts of the Stomach
- This is the area where the esophagus meets with the stomach – esophagogastric junction (Z-line).
- The passage of food through this area is regulated by the lower esophageal sphincter (LES) or cardiac sphincter.
- This is the uppermost area of the stomach that lies just under the diaphragm.
- It ends in line with the cardia.
- This is the largest part of the stomach between the fundus and pylorus.
- This is the area through which the gastric contents flow out of the stomach and into the duodenum.
- It is divided into the pyloric antrum which lies next to the body and the pyloric canal which lies next to the duodenum.
- The passage of food from the stomach into the duodenum is regulated by the pyloric sphincter.
The anatomical position of the stomach varies during respiration (breathing in and out), after eating or when empty and whether a person is lying down (supine), sitting or standing.
Source : Wikimedia Commons
In the supine position the stomach occupies the right upper quadrant (RUQ) and left upper quadrant (LUQ) or more specifically the epigastrium (E), left hypochondrium (LH), umbilical (U) and left lateral/lumbar (LL) / left flank regions.
Location of Parts of the Stomach
Due to varying positions of the stomach, it is best assessed when lying down (supine). Individual variations of size and shape of the stomach may also have to be taken into account.
The image above is only intended to guide the reader to the location of the stomach and structures may be out of scale.
When supine, the parts of the stomach are located as follows :
- Posterior (behind) the left 6th costal cartilage.
- Posterior (behind) to and slightly superior (above) the left 6th rib.
- Lies above and below the junction of the epigastric and umbilical regions with the pyloric antrum being in line with the midline of the the body.
- The pyloric canal lies to the left of the antrum.
- Extends from the 5th intercostal space (above the left 6th rib) and curves down the left hypochondrium (LH).
- Enters the upper middle (anteromedial) part of the left lateral/flank region (LL) and meets with the pyloric antrum in the umbilical region.
- Extends from the cardia to superior (uppermost) aspect of the pyloric antrum (in the lower part of the epigastrium) at a junction known as the angular incisure.
- The body of the stomach lies in the area between the fundus and pylorus.