Third year

GIT..
Anatomy
Lecture(5)
Anatomy of Stomach

Dr. Amany Swilam

Assistant professor of Anatomy & Embryology

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ILOs

1. Describe the location, shape, opening, surfaces, and relations of stomach.

2. Understand the blood & nerve supply and Lymph drainage of stomach.

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Stomach
Def.: It is the most dilated part of the
alimentary canal. It lies between the
oesophagus and the duodenum.

Its capacity; in adult about 1500ml. At

birth, only 30ml.

Description: Stomach has:

 Two Orifices,
 Two Borders (curvatures)&
 Two Surfaces.

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Location of the stomach Shape of the stomach
It lies in 3 abdominal regions; the left 1- J shaped: vertical –commonest

hypochondrium, epigastric and umbilical especially in tall thin persons

regions. 2- Steer (ox) horn: horizontal - less

common
3- intermediate.

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Orifices of Stomach
 The stomach has two orifices through which it
communicates with the oesophagus above (cardiac
orifice) and with the duodenum below (pyloric
orifice).
1- Cardiac Orifice:
• It receives the abdominal part of the
oesophagus.
• The right border of oesophagus continuous with
lesser curvature of stomach.
• The left border is separated from the greater
curvature by an acute angle called cardiac
notch.
• Sphincter: There is no true anatomical
sphincter related to this orifice.
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Orifices of stomach

Surface anatomy of Cardiac

orifice:
• It lies (1 inch) to the left of the
midline.

• It lies behind the 7th costal cartilage

at the level of the T11 vertebra.

• It is placed (40 cm) from the incisor

teeth.

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Orifices of stomach
2- Pyloric orifice:
 The pyloric orifice lies at the junction of the stomach with
the duodenum.
 Surface anatomy: It lies on the transpyloric plane (L1), (0.5
inch to the right of the median plane).
 The pyloric sphincter: True anatomical sphincter. it is a
muscular ring, formed by a marked thickening of the circular
gastric muscle.
To identify the pylorus in surgical procedures:
a- Circular groove (pyloric constriction).
b- The prepyloric vein of Mayo (seen only in the living) which passes
vertically across the anterior surface of the pylorus. It communicates the
right gastric vein (above the pylorus) with right gastroepiploic vein (below
the pylorus).
c- Thickness of the pyloric sphincter. 7
Borders (curvatures) of the
stomach
1-Lesser curvature:
• It is the right concave border of the
stomach.
• It extends from the cardiac orifice to
the pylorus.
• It has a constant notch called angular
incisura.
• It gives attachment to the lesser
omentum.

• Related to: Rt& Lt gastric vessels and

lymph nodes between the 2 layers of
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the lesser omentum.
Borders (curvatures) of the stomach
2-Greater curvature:
• It is the left convex border of the stomach.
• It begins at the Lt margin of the oesophagus.
• It arches upward, backward and to the left forming the
fundus.
• Then it passes downwards and to the right to end at
the pylorus.
• It gives attachment to Gastrophrenic, Gastrosplenic &
Greater omentum.

• Related to: Rt & Lt gastroepiploic vessels and lymph

nodes, between the anterior 2 layers of the greater
omentum & gastrosplenic ligament. 9
Surfaces of the stomach
1- Antero-superior surface:
 It is directed forward and slightly upward.
 It is covered by peritoneum of the greater sac.

It is related anteriorly to (covered by) the

following structures:

Its left part: Diaphragm and the left 6th,

7th & 8th ribs and their costal cartilages.

Its right part: Left lobe of the liver.

Its lower part: Anterior abdominal wall.

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Surfaces of the stomach
2- Postero- inferior surface:
• It is directed backward and slightly downward.
• It is covered by peritoneum of the lesser sac.

It is related posteriorly (lies over) a number of

structures that forming the stomach bed, these are
the following:
 Diaphragm.
 Anterior surface of Lt kidney& Lt suprarenal gland.
 Anterior surface of the Pancreas& Splenic artery.
 Spleen.
 Transverse colon& transverse mesocolon.
 The lesser sac separates the stomach from the
stomach bed.
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Parts of the Stomach
The stomach consists of three parts: fundus, body
and pyloric parts.
The internal appearance and microstructure of these regions
varies to some degree.

1-The fundus:
• It is dome shaped and projects above and to the
left of the cardiac orifice.
• It lies in contact with the left dome of the
diaphragm.
• It is usually distended with gas.

2-The body of stomach:

• It is the part below the fundus and above the line
(extending from the angular incisura to the greater
curvature).
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Parts of the stomach
3-The pyloric part:
• It lies below and to the right of the body of the
stomach.
• It consists of:
a- Pyloric antrum: It is the dilated proximal part.

b- Pyloric canal: It is narrow cylindrical part that

follows the pyloric antrum.

c- Pyloric orifice with pyloric sphincter (pylorus):

It is the most distal thickened portion.

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Peritoneal relation of the stomach
 The anterior surface is covered by
peritoneum of greater sac.

 The posterior surface is covered by

peritoneum of lesser sac, except a small area
close to the cardiac orifice (bare area of the
stomach) that is related to the left crus of the
diaphragm.

 The peritoneal folds attached to the

stomach are:
1- Lesser omentum.
2- Greater omentum.
3- Gastrosplenic ligament.
4- Gastrophrenic ligament. 14
Lesser Omentum
Borders& contents:
1- Hepatic border:
• It is attached to the liver (fissure for the ligamentum
venosum and margins of the porta hepatis).
2-Gastric border:
• It is attached to the lesser curvature of the somach and
1st part of the duodenum.
• It contains; Rt & Lt gastric vessels and left gastric lymph
nodes.
3-Diaphragmatic border:
• It is attached to the diaphragm.
4- Right free border:
• It is free in which the two layers are continuous with each
other.
• It contains: Portal vein, Hepatic artery & Common bile
duct.
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Peritoneal relation of the stomach
Gastrosplenic ligament:
■Attachments: It is a peritoneal fold which extends
between the upper part of greater curvature of
the stomach and the hilum of the spleen.
■Contents:
1-Short gastric vessels.
2-Part of the left gastroepiploic vessels.
3-Lymphatics and lymph nodes.
4-Autonomic nerve fibers.
5-Extraperitoneal fat.

Gastrophrenic ligament:
 It is a peritoneal fold which extends between the upper
most part of greater curvature and the diaphragm.
 It contains only fat .
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Blood supply of the stomach
Arterial supply:
• Five arteries supply the stomach.
• These arteries are derived from the branches of
the coeliac trunk.

1-Left gastric artery:

• It arises from the coeliac trunk.
• It supplies the abdominal part of oesophagus
and right part of the body of the stomach.

2-Right gastric artery:

• It arises from the hepatic artery.
• It supplies the upper part of the pyloric portion
of stomach.
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Blood supply of the stomach
3-Right gastroepiploic artery:
• It arises from the gastroduodenal artery.
• It supplies the lower part of the pyloric
portion of stomach.

4-Left gastroepiploic artery:

• It arises from the splenic artery.
• It supplies the left part of the body of the
stomach.

5-Short gastric arteries (about 5-7):

• They arise from the splenic artery.
• They supply the fundus of the stomach.
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Venous drainage of the stomach

The vein Drain into

1-Left gastric v.
Portal vein
2-Right gastric v.
3-Right Superior
gastroepiploic v. mesenteric vein
4-Left
gastroepiploic v.
Splenic vein
5-Short gastric
veins

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Lymphatic drainage of stomach

• Lymph vessels follow the course of the

arteries that supplying the stomach.
• They drain into many separate groups of
nodes in relationship to the regions of the
stomach for e.x. left gastric, right and left
gastroepiploic nodes, Pancreaticosplenic
nodes.

• Lymphatic vessels from these nodes pass

to the coeliac nodes.

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Nerve supply of the stomach
A-The sympathetic fibers:
They arise from the spinal cord segments from (T6

to T10).

Gastric Pain:
The sensation of pain in the stomach is caused by
the stretching or spasmodic contraction of the
smooth muscle and is referred to the epigastrium.

B-Parasympathetic fibers (from vagi):

From both vagus nerves through the anterior
and posterior gastric nerves.
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Surface anatomy of the stomach
1-Cardiac end: Discussed before.
2-Pyloric end: Discussed before.

3-Fundus of the stomach:

 It represents by a point in the left 5th
intercostal space, 3.5 inches to the left
of median plane.

The lesser curvature represents curved

line between points 1&2. The greater
curvature represents curved line
between1,3& 2.
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Applied anatomy
The gastric ulcers are common in the lesser curvature in the pyloric
region due to less blood supply to pyloric end in relation to size and
there is no submucosal plexus.

Since the pancreas lies behind the stomach, acute pancreatitis is

frequently diagnosed as gastritis.

An ulcer in the posterior wall of stomach may penetrate the wall
and erode the splenic artery, causing a sever hemorrhage or
become adherent to the pancreas (Erosion of the pancreas).

A penetrating ulcer of the anterior stomach wall may result in; the
escape of stomach contents into the greater sac, producing diffuse
peritonitis. The anterior stomach wall may, however, adhere to the
liver, and the chronic ulcer may penetrate the liver substance.
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