The stomach is the widest part of the digestive tract, a J-shaped muscular bag between the oesophagus and the duodenum. It lies mostly in the left upper abdomen under the ribs, and its shape and position change a lot with posture and how full it is. It is divided into the cardia, fundus, body, pyloric antrum and pylorus, with a short lesser curvature on the right and a long greater curvature on the left.
| Location | Left upper quadrant and epigastrium, below the left dome of the diaphragm, from the gastro-oesophageal junction (about T11) to the pylorus (about L1) |
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| Nerve Supply | Anterior and posterior vagal trunks (parasympathetic); Coeliac plexus, from greater splanchnic nerves T6-T9 (sympathetic) |
| Blood Supply | Left gastric artery; Right gastric artery; Right gastro-omental artery; Left gastro-omental artery; Short gastric arteries; Posterior gastric artery (when present) |
| Venous drainage |
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| Lymphatic drainage |
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Stores swallowed food, mixes it with acid and pepsin to begin protein digestion, kills many microbes, secretes intrinsic factor for vitamin B12 absorption and releases chyme into the duodenum at a controlled rate.
Upper abdominal pain, early fullness, vomiting and bleeding point to stomach disease; red flags such as weight loss, anaemia or difficulty swallowing need prompt endoscopy. Helicobacter pylori infection and NSAIDs cause most peptic ulcers, and H. pylori is also a major risk factor for gastric cancer. The rich arterial network along both curvatures means the stomach survives ligation of several of its arteries, which makes it useful for reconstruction after oesophagectomy.
Breach of the stomach lining, usually from H. pylori or NSAIDs, causing epigastric pain and sometimes bleeding or perforation.
Malignant tumour of the stomach lining that often presents late with weight loss, early satiety, anaemia or a palpable left supraclavicular node.
Chronic bacterial infection of the stomach lining causing inflammation, peptic ulcers and an increased risk of gastric cancer and MALT lymphoma.
