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Oesophagus | Main Anatomy Index | The
Last updated 30 March 2006
- The stomach is the most dilated part of the alimentary canal.
- It is located between the oesophagus and the small
- In the supine position, it is usually located in the
left upper quadrant, where it occupies parts of the epigastric,
umbilical, and left hypochondriac
- In most people, the stomach is J-shaped and its pyloric
part lies horizontally or ascends to the duodenum.
- The stomach is a very distensible organ. The empty stomach is only of slightly larger
calibre than the large intestine.
- It can, however, undergo considerable expansion and hold 2-3 litres of food.
Curvatures of the Stomach
The Lesser Curvature
- This is continuous with the right border of the oesophagus
and forms the concave border of the stomach.
- The angular notch (incisura angularis) is a sharp
angulation of the lesser curvature, which indicates the junction of the body and pyloric
parts of the stomach.
- This border is the attachment of the lesser
The Greater Curvature
- This is continuous with the left border of oesophagus and
forms the convex border of the stomach.
- The greater curvature is 4 to 5 times longer than the lesser curvature.
- This border is the attachment of the greater
omentum and gastrosplenic ligament.
Parts of the Stomach
- This, with the cardiac orifice is situated to the left
of the midline behind the 7th costal cartilage,
2.5 cm from its sternal junction at the level of T11.
- This is a rounded vault to the left and superior to the cardiac orifice.
- The fundus is the most superior part of the stomach and is related to the left dome of the diaphragm.
- It is separated from the cardiac part by the cardiac notch or
The Body of the Stomach
- This is the main portion of the stomach.
- It lies between the fundus and pyloric antrum.
The Pyloric Part of the
- This consists of a wide portion, the pyloric antrum,
and a narrow portion, the pyloric canal.
- The pyloric canal (1 to 2 cm long) is continuous with
the markedly constricted part, the pylorus.
- The pylorus of the stomach (G. gatekeeper) is the distal sphincteric region that guards
the pyloric orifice.
- Its wall is thicker because it contains extra circular smooth muscle.
- The pylorus is normally in tonic contraction.
- At irregular intervals, gastric peristalsis passes
chyme through the pyloric canal to the small intestine.
- The pyloric orifice lies about 1.2 cm to the right of the midline in the transpyloric plane (L1) when the stomach is empty and the
Relations of the Stomach
- The stomach is covered completely by peritoneum, except
where the blood vessels run along its curvatures, and a small bare
area posterior to the cardiac orifice.
- Left costal margin
- Left diaphragm (6th to 9th intercostal
- Gastric surface of the spleen
- Left and quadrate lobes of the liver
- Anterior abdominal wall
- Transverse colon (when the stomach is empty)
The Posteroinferior surface
- Superiorly: part of the diaphragm (left crus), the
spleen, the left suprarenal gland and upper pole of the left kidney.
- Inferiorly: body and tail of pancreas, transverse
mesocolon, left colic flexure and the splenic artery.
The Stomach Interior
- There are longitudinal mucosal folds called rugae and
run from high in the body to the pyloric antrum and canal.
Phases of Gastric
- Cephalic: secretion in response to smell and taste of
- Gastric: in response to the presence of food in the
- Intestinal: gastric secretion and motility is decreased by impulses from the duodenum.
Arterial Supply to the Stomach
- The stomach has a rich blood supply from all three branches of the coeliac
The Left Gastric Artery
- This is a small branch of the coeliac trunk.
- At the stomach, it runs from the cardiac part of the stomach
along the lesser curvature, frequently as two branches, to the pylorus.
- It sits between the layers of the lesser omentum
- It supplies both surfaces of the stomach and anastomoses with the right gastric artery.
The Right Gastric Artery
- This is a branch of the common hepatic artery.
The Left Gastro-omental
- This is a branch of the splenic artery and runs along
the greater curvature of the stomach.
- This vessel runs between the layers of the greater
omentum, a short distance from its attachment to the stomach.
The Right Gastro-omental
- This is a branch of the gastroduodenal artery.
- It runs towards the left and anastomoses with the left gastro-omental artery.
- It sends branches to the right part of the stomach and superior part of the duodenum.
The Short Gastric Arteries
- These are also branches of the splenic artery.
- There are usually 4-5 of these.
- They run between the layers of the gastrosplenic ligament
to the fundus of the stomach.
- They anastomose with the left gastric and left gastro-omental arteries.
Venous Drainage of
- The larger veins usually accompany the main arteries.
- The right gastro-omental vein drains into the superior mesenteric vein, and then into the portal
- The left gastro-omental vein drains into the splenic vein and then into the portal
- The left and right gastric veins drain into the portal vein directly.
of the Stomach
- Gastric lymphatics are continuous at the pylorus with the duodenal lymphatics and the oesophageal lymphatics at the
- Lymph channels largely follow the blood vessels and 4 main groups
have been identified.
- Right Gastro-omental group: the drains the greater curvature as far as the pylorus.
- These nodes drain into the pyloric nodes.
- All the nodes eventually drain into the coeliac nodes
and from there to the thoracic duct.
Nerve Supply of the
- This is from the greater and lesser splanchnic nerves
and left phrenic nerve to the coeliac
- Then, it is through extensions of the coeliac plexus
along the gastric and gastro-omental arteries.
- The anterior and posterior gastric nerves are usually derived from the left and right
The anterior vagal trunk gives rise to:
- Hepatic branches and pyloric branches.
- A fundal branch to the fundus.
- The anterior nerves of Latarjet.
The posterior vagal trunk gives rise to:
- Coeliac branches to the coeliac plexus around the coeliac trunk.
- The posterior nerves of Latarjet.