•   Stomach is a dilated portion of the alimentary tract
• situated in the upper part of the abdomen

• Continuous with oesophagus
• Cardiac orifice
• Pyloric orifice ' pyloric sphincter
• Opens into the duodenum
• The curved right border is called the lesser curvature
• The curved left border is called the greater curvature
• The upper opening of the stomach into the oesophagus is guarded by a physiological sphincter called cardiac sphincter.

• The part above the cardiac orifice ' fundus
• The main part ' body
• The lower part ' antrum
• The opening into the duodenum guarded by the pyloric sphincter - anatomical sphincter ' increased number of circular muscle fibres

•   adventitial layer   peritoneum - extends beyond the greater curvature as the greater omentum
•    muscle layer   outer longitudinal fibres, middle layer of circular fibres, an inner layer of oblique fibres
•   mucosa   longitudinal folds of mucosa called rugae - disappear when the stomach is full. - gastric glands - gastric juice.

• coeliac artery : right gastric artery, left gastric artery, right gastroduodenal artery, left gastroduodenal artery, short gastric arteries
• venous drainage into the portal vein

• sympathetic supply from coeliac plexus
• parasympathetic supply from the vagus nerves

• Temporary storage for food allowing time for the digestive enzymes to act
• Chemical digestion - pepsin converts proteins to polypeptides
• Mechanical digestion - the stomach contents are triturated and made into smaller particles   chyme
• Limited absorption of water, alcohol and some lipid soluble drugs.
• Non-specific defence against microbes - by hydrochloric acid , vomiting
• Helps iron absorption to be done in the small intestines.
• Production of intrinsic factor  needed for absoption of vitamin B12
• Controlled release of the stored contents into the duodenum.