Stomach

STOMA
CH
MR. ABHIJIT P. BHOYAR
ASST. PROFESSOR
CHILD HEALTH NURSING

The stomach is also called the gaster
(Greek belly) or venter from which we
have the adjective gastric applied to
structures related to the organ.
The stomach is an important organ and
the most dilated portion of the digestive
system.

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 the oesophagus, and below to
the duodenum. It acts as a reservoir of food
and helps in digestion of carbohydrates,
proteins and fats.

The stomach lies obliquely in the upper
and left part of the abdomen, occupying
the epigastric, umbilical and left
hypochondriac regions. Most of it lies
under cover of the left costal margin and
the ribs.

 The shape of the stomach depends upon the degree of tone of its muscles
and tone of muscles of the body.
 In normal active persons (sthenic), its shape is somewhat J-shaped
 In thin, tall persons (hyposthenic), its shape is J-shaped, while in broad,
strong and very active persons, its shape is horizontal.
 The shape of the stomach can be studied in the living by radiographic
examination after giving a barium meal

The stomach is a very distensible organ.
It is about 25 cm long, and the mean capacity is one ounce (30 ml)
at birth, one litre (1000 ml) at puberty, and 1½ to 2 litres or more
in adults.

The stomach has two orifices or
openings, two curvatures or
borders, two surfaces and two
parts.

1) THE CARDIAC ORIFICE is joined by the lower end of the
oesophagus.
It lies behind the left 7th costal cartilage 2.5 cm from its junction
with the sternum, at the level of vertebra T11.

2) THE PYLORIC ORIFICE opens into the duodenum. In an empty stomach and in
the supine position, it lies 1.2 cm to the right of median plane, at the level of lower
border of vertebra L1 or transpyloric plane. Its position is indicated on the surface of the
stomach:
 a. By a circular groove (pyloric constriction produced by the underlying pyloric
sphincter or pylorus; pylorus = gate guard) which feels like a large firm nodule.
 b. By the prepyloric vein which lies in front of the constriction.

TWO CURVATURES
LESSER
CURVATURE
•The lesser curvature is concave and forms the right border of the stomach. It
provides attachment to the lesser omentum. The most dependent part of the
curvature is marked by the angular notch or incisura angularis.
GREATER
CURVATURE
•The greater curvature is convex and forms the left border of the stomach. It
provides attachment to the greater omentum, the gastrosplenic ligament and
the gastrophrenic ligament. At its upper end, the greater curvature presents
the cardiac notch which separates it from the oesophagus. It is 5 times
longer than lesser curvature.

TWO SURFACES
The anterior or antero
superior surface faces
forwards and upwards.
The posterior or
postero inferior surface
faces backwards and
downwards.

 The stomach is divided into two parts—cardiac and pyloric.
 By a line drawn downwards and to the left from the cardiac end to the
angular notch (lowest point of lesser curvature).
 The line is extended further to the greater curvature.
 The larger cardiac part is further subdivided into fundus and body.
 The smaller pyloric part is subdivided into pyloric antrum and pyloric
canal

CARDIAC PART
1. The fundus of the stomach is the upper convex dome shaped part
situated above a horizontal line drawn at the level of the cardiac
orifice.
It is commonly distended with gas which is seen clearly in
radiographic examination under the left dome of the diaphragm
2. The body of the stomach lies between the fundus and the pyloric
antrum.

It can be distended enormously along the greater curvature. The
gastric glands, distributed in the fundus and body of stomach,
contain all three types of secretory cells, namely:
a. The mucous cells.
b. The chief, peptic or zymogenic cells which secrete the digestive
enzymes.
c. The parietal or oxyntic cells which secrete HCl.

PYLORIC PART
1. The pyloric antrum is separated from the pyloric canal by an
inconstant sulcus, sulcus intermedius present on the greater
curvature.
It is about 7.5 cm long.
The pyloric glands are richest in mucous cells.
2. The pyloric canal is about 2.5 cm long. It is narrow and tubular.
At its right end, it terminates at the pylorus.

 Peritoneal Relations
 The stomach is lined by peritoneum on both its surfaces.
 At the lesser curvature, the layers of peritoneum lining the anterior and
posterior surfaces meet and become continuous with the lesser omentum
 Along the greater part of the greater curvature, the two layers meet to form the
greater omentum.

Near the fundus, the two layers meet to form the gastrosplenic
ligament.
Near the cardiac end, the peritoneum on the posterior surface is
reflected onto the diaphragm as the gastrophrenic ligament
The greater and lesser curvatures along the peritoneal reflections
are also bare.

VISCERAL RELATIONS
The anterior surface of the stomach is related to the liver, the
diaphragm, and the anterior abdominal wall.
The diaphragm separates the stomach from the left pleura, the
pericardium, and the sixth to ninth ribs.
The space between left costal margin and lower edge of left lung on
stomach is known as Traube’s space.

The costal cartilages are separated from the stomach by the
transversus abdominis.
Gastric nerves and vessels ramify deep to the peritoneum.
Normally, on percussion, there is resonant note over this space; but
in splenomegaly or pleural effusion, a dull note is felt at this site.

 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

Sometimes the spleen is also included in the stomach bed, but it is
separated from the stomach by the cavity of the greater sac (and not
of the lesser sac).
Gastric nerves and vessels ramify deep to the peritoneum.

 The stomach is supplied along:
 i. The lesser curvature by: The left gastric artery, a branch of the coeliac trunk
and the right gastric artery, a branch of the proper hepatic artery.
 ii. The greater curvature: It is supplied by the right gastroepiploic artery, a
branch of the gastro-duodenal and the left gastroepiploic artery, a branch of
the splenic artery.
 iii. Fundus is 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.
 Right and left gastric veins drain in the portal vein.
 Right gastroepiploic vein ends in superior mesenteric vein; while left
gastroepiploic and short gastric veins terminate in splenic vein

FEATURES
1. The mucosa of an empty stomach is thrown into folds
termed as gastric rugae.
 The rugae are longitudinal along the lesser curvature and
may be irregular elsewhere.
 The rugae are flattened in a distended stomach. On the
mucosal surface, there are numerous small depressions that
can be seen with a hand lens. These are the gastric pits.
 The gastric glands open into these pits.

 The part of the lumen of the stomach that lies along the lesser curvature, and
has longitudinal rugae, is called the gastric canal or magenstrasse.
 This canal allows rapid passage of swallowed liquids along the lesser curvature
directly to the lower part before it spreads to the other part of stomach.
 Thus lesser curvature bears maximum insult of the swallowed liquids, which
makes it vulnerable to peptic ulcer.
 So, beware of your drinks

2 Submucous coat is made of connective tissue, arterioles and nerve plexus.
3 Muscle coat is arranged as under:
 a. Longitudinal fibres are most superficial, mainly along the curvatures.
 b. Inner circular fibres encircle the body and are thickened at pylorus to form
pyloric sphincter
 c. The deepest layer consists of oblique fibres which loop over the cardiac
notch.

 Some fibres spread in the fundus and body of stomach.
 Rest form a well-developed ridge on each side of the lesser curvature.
 These fibres on contraction form ‘gastric canal’ for the passage of fluids.
4. Serous coat consists of the peritoneal covering.

The gastric glands
also produce
hydrochloric acid
which destroys
many organisms
present in food
and drink.
The lining cells of
the stomach
produce abundant
mucus which
protects the
gastric mucosa
against the
corrosive action of
hydrochloric acid.
Some substances
like alcohol, water,
salt and a few
drugs are absorbed
in the stomach.
Stomach produces
the ‘intrinsic
factor’ of Castle
which helps in the
absorption of
vitamin B12.

 Gastric pain is felt in the epigastrium because the stomach is supplied from
segments T6 to T9 of the spinal cord, which also supply the upper part of the
abdominal wall.
 Pain is produced either by spasm of muscle, or by over-distension.
 Ulcer pain is attributed to local spasm due to irritation

 Peptic ulcer can occur in the sites of pepsin and hydrochloric acid, namely the
stomach, first part of duodenum, lower end of oesophagus and Meckel’s
diverticulum. It is common in blood group ‘O’.
 Gastric ulcer occurs typically along the lesser curvature.
 This is possibly due to the following peculiarities of lesser curvature.

a. It is homologous with the gastric trough of ruminants.
b. Mucosa is not freely movable over the muscular coat.
c. The epithelium is comparatively thin.
d. Blood supply is less abundant and there are fewer anastomoses.
e. Nerve supply is more abundant, with large ganglia.
f. Because of the gastric canal, it receives most of the insult from irritating
drinks.
g. Being shorter in length, the wave of contraction stays longer at a particular
point, viz. the standing wave of incisura.
h. Helicobacter pylori infection is also an important causative factor.

 Gastric ulcers are common in people who are always in ‘hurry’, mostly ‘worry’ about
incidents and eat ‘spicy curry’.
 Gastric ulcer is notoriously resistant to healing and persists for years together, causing great
degree of morbidity. To promote healing, the irritating effect of HCl can be minimised by
antacids, partial gastrectomy or vagotomy.
 Gastric carcinoma is common and occurs along the greater curvature. On this account, the
lymphatic drainage of stomach assumes importance.

 Metastasis can occur through the thoracic duct to the left supraclavicular lymph node
(Troisier’s sign). These lymph nodes are called ‘signal nodes’.
 It is common in blood group ‘A’.
 Pyloric obstruction can be congenital or acquired.
 It causes visible peristalsis in the epigastrium and vomiting after meals (thin and long).
 Hyposthenic stomach is (long and narrow) more prone for gastric ulcer, while hypersthenic
stomach is prone for duodenal ulcer (short and broad).

1. Describe stomach under
following headings.
 a. Position
 b. Gross features
 c. Peritoneal and visceral
relations
 d. Blood supply and lymphatic
drainage
 e. Clinical anatomy
2. Write short notes on:
 a. Abdominal part of oesophagus
 b. Portocaval anastomosis at
lower end of
 oesophagus
 c. Stomach bed

 1. Following structures form part
of the stomach bed, except:
 a. Left suprarenal gland
 b. Coeliac trunk
 c. Splenic artery
 d. Pancreas
 2. Which of the following is not
present in the bed of stomach?
 a. Splenic artery
 b. Transverse mesocolon
 c. Transverse colon
 d. Fourth part of duodenum

 3. A posteriorly perforating peptic
ulcer will most likely produce
peritonitis in the following:
 a. Greater sac
 b. Lesser sac
 c. Bare area of liver
 d. Morrison’s pouch
 4. Which of the following arteries
supplies the fundus of the stomach?
 a. Right gastric artery
 b. Splenic artery
 c. Short gastric arteries
 d. Gastroduodenal artery

 5. Which cell of gastric gland
gives it a beaded appearance?
 a. Zymogenic
 b. Oxyntic
 c. Mucus cells
 d. Columnar cell
 6. Cardiac orifice of stomach lies
behind one of the following costal
cartilages:
 a. Left fifth
 b. Left seventh
 c. Left eighth
 d. Right eighth

1. b 2. d 3. b 4. c 5. b 6. b

Stomach

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