2. STOMACH
The stomach is a muscular bag forming the widest
and most distensible part of the digestive tube.
It is connected:
Above – to the lower end of oesophagus
Below – to the duodenum
It is almost:-
o 25 cm long ,
o J shaped &
o it act as reservoir of food
3. Location
It lies obliquely in the upper & left part of the
abdomen. Occupying the:-
* Epigastric
* Umbilical and
* Left hypochondriac regions.
It’s mean capacity :-
At birth:- 30 ml
At puberty:- 1 litre
Adults:- 1.5 – 2 litres or more
4. External Features:
The stomach has:-
1. Two orifices or openings
2. Two curvatures or borders
3. Two surfaces and two parts
4. Two parts
5. Two Orifices
• Cardiac orifice
• Pyloric orifice
Two Curvatures
• Lesser curvature
• Greater curvature
Two Surfaces
• The anterior
• The posterior
Two Parts
Cardiac and pyloric.
Cardiac Part Divided into:
1. The fundus of the stomach
2. The body of the stomach
Pyloric Part Divided into:
1. The pyloric antrum
2. The pyloric canal
7. 1.Two Orifices/ openings
1. Cardiac orifice:
o Joined by the lower end
of the oesophagus
o It lies behind the left 7th costal cartilage
o Lies at the level of T11
2. Pyloric orifice: (pylorus means gate guard)
o It opens into the duodenum
o It lies at the transpyloric plane
8. 2. Two Curvatures
1. Lesser curvature :
o It is concave & forms the
right border of the stomach
o It provides attachment to the lesser omentum
o The most dependent part of the curvature is marked by the:
angular notch or incisura angularis
2. Greater curvature:
o It is convex & forms the left border of the stomach
o It provides attachment to the greater omentum, gastrosplenic
& gastrophrenic ligament
o At upper end there is cardiac notch which separate it from
oesophagus
o It is 5 times longer than the lesser curvature
9. 3. Two Surfaces
a. The anterior or anterosuperior surface
Faces forwards & upwards
a. The posterior or posteroinferior surface
Faces backwards & downwards
10. 4.Two Parts
1. Cardiac Part Divided into:
a. The fundus
o upper convex dome shaped part
o Commonly distended with gas
b. The body
o Lies between the fundus & the pyloric antrum
Fundus & body contains all three types of secretory cells:
a. The mucous cells
b. The chief, peptic/zygomen cells: secretes digestive
enzymes
c. The parietal/oxyntic cells: secretes HCL
11. 2. Pyloric Part:
1. The pyloric antrum
o It is separated from the
Pyloric canal by sulcus
intermedius
o It’s about 7.5 cm long
2. The pyloric canal
o it is 2.5 cm long
o It is narrow & tubular
o At its right end, it
terminates at the pylorus
12. Relations of Stomach: Peroitoneal relation
The stomach is lined by peritoneum on both of its
surfaces
• At lesser curvature its continuous with lesser
omentum
• At greater curvature its continuous with greater
omentum
• Near the fundus, the two layers forms the
gastrosplenic ligament
• Near the cardiac end, the peritoneum on the
posterior surface is reflected on the diaphragm as
gastrophrenic ligament.
13. Visceral Relations
The anterior surface of the stomach is related to :
• The liver
• The diaphragm,
• Transverse colon and
• The anterior abdominal wall.
14. Anterior relations of stomach
1. Area 1st is covered by the liver;
2. Area 2nd by the diaphragm; and
3. Area 3rd by the anterior abdominal wall
15. The posterior surface of the stomach is related to :
structures forming the stomach bed, all of which are
separated from the stomach by the cavity of the lesser
sac.
These structures are:
a. Diaphragm
b. Left kidney
c. Left suprarenal gland
d. Pancreas
e. Transverse mesocolon
f. Splenic flexure of the colon
g. Splenic artery.
17. BLOOD SUPPLY
1.The lesser curvature:
The left gastric artery, a branch of the coeliac trunk and
the right gastric artery.
2. The greater curvature:
The right gastroepiploic artery, a branch of the
gastroduodenal and
The left gastroepiploic artery, a branch of the splenic.
3. Fundus:
supplied by 5 to 7 short gastric arteries, which are also
branches of the splenic artery.
The veins of the stomach drain into the portal, superior
mesenteric and splenic veins
19. LYMPHATIC DRAINAGE
The stomach can be divided into four lymphatic territories
A. Upper part of left 1/3rd :- pancreaticosplenic nodes
Lymph vessels from these nodes travel along the splenic artery
to reach Coeliac nodes
B. Right 2/3rd :- left gastric nodes Coeliac nodes
C. Lower part of left 1/3rd right gastroepiploic nodes
subpyloric nodes hepatic nodes Coeliac nodes
D. Pyloric part: pyloric, hepatic & left gastric nodes
Coeliac nodes
21. Nerve Supply
The sympathetic nerves are derived from T6 to T10
segments of the spinal cord,
These nerves are
a. Vasomotor.
b. Motor to the pyloric sphincter, but inhibitory to the
rest of the gastric musculature.
c. The chief pathway for pain sensations from the
stomach
The parasympathetic nerves are derived from the
vagus
22. 1. The anterior gastric nerve gives: (contains left
vagal fibres)
• A number of gastric branches for the anterior
surface of the fundus and body of the stomach.
• Two pyloric branches,
2. The posterior gastric nerve (right vagal fibres)
• Smaller, gastric branches for the posterior surface
of the fundus
• Larger, coeliac branches for the coeliac plexus.
23. Nerve supply of the stomach: (a) Anterior gastric nerve, and (b)
posterior gastric nerve
24. Interior of Stomach
1 The mucosa of an empty stomach is thrown into
folds termed as gastric rugae
On the mucosal surface there are numerous
gastric pits
2 Submucous coat
3 Muscle coat:
(a) Longitudinal fibres
(b) Inner circular fibres encircle the body and are
thickened at pylorus
(c) The deepest layer consists of oblique fibres
which loop over the cardiac notch
4 Serous coat
26. FACTS TO REMEMBER (Contd.)
• Abdominal part of oesophagus is the site of
portosystemic anastomoses. Some veins drain into
hemiazygos vena azygos superior vena
cava. Other veins drain into oesophageal veins
left gastric vein portal vein.
• Stomach comprises:
Two orifices: Cardiac and pyloric
Two curvatures: Lesser and greater
Two parts: Cardiac and pyloric
Cardiac part: Fundus and body
Pyloric part: Pyloric antrum and pyloric canal.
• .
27. • Lesser curvature is the anterior border and greater curvature
is the posterior border.
• Left and right gastric arteries run along lesser curvature.
• Left and right gastroepiploic arteries lie along greater
curvature.
• Pylorus is identified by prepyloric vein
• Stomach bed is separated from the stomach by lesser sac.
• The gastric ulcer is common in people who “worry, hurry and
eat hot curries”. Gastric ulcer commonly occurs along lesser
curvature.
• Gastric cancer mostly occurs along greater curvature. Lymph
from cancer thoracic duct left supraclavicular node. It is
called Virchow’s node. This sign is called Troisier’s sign.
