What is gastric ulcer?
Gastric ulcers most often occur within the body of the stomach along the
lesser curvature above the incisura angularis.
Gastric ulcer occurs typically along the lesser
curvature. This is possibly due to the following peculiarities of the lesser curvature:
(i) It is homologous with the gastric trough of ruminants,
(ii) Mucosa is not freely movable over the muscular coat.
(Ill) The epithelium is comparatively thin,
(iv) Blood supply is less abundant and there are fewer anastomoses,
(v) Nerve supply is more abundant, with large ganglia,
(vi) Because of the gastric canal, it receives most of the insult from irritating drinks,
(vii) Being shorter in length the wave of contraction stays longer at a particular point, viz., the standing
wave of incisura.
Gastric ulcer is notoriously resistant to healing and
persists for years together, causing great degree of
morbidity. To promote healing the irritating effect of
HC1 can be minimised by antacids, partial
gastrectomy, or vagotomy.
What are Symptoms of Gastric ulcer?
Burning stomach pain
Feeling of fullness, bloating or belching
Intolerance to fatty foods
Heartburn
Nausea
The most common peptic ulcer symptom is burning stomach pain. Stomach acid makes the pain worse, as does having an empty stomach. The pain can often be relieved by eating certain foods that buffer stomach acid or by taking an acid-reducing medication, but then it may come back. The pain may be worse between meals and at night.
Many people with peptic ulcers don't even have symptoms.
Less often, ulcers may cause severe signs or symptoms such as:
Vomiting or vomiting blood — which may appear red or black
Dark blood in stools, or stools that are black or tarry
Trouble breathing
Feeling faint
Nausea or vomiting
Unexplained weight loss
Appetite changes
What are causes of Gastric ulcer?
Peptic ulcers occur when acid in the digestive tract eats away at the inner surface of the stomach or small intestine. The acid can create a painful open sore that may bleed.
Your digestive tract is coated with a mucous layer that normally protects against acid. But if the amount of acid is increased or the amount of mucus is decreased, you could develop an ulcer.
Common causes include:
A bacterium. Helicobacter pylori bacteria commonly live in the mucous layer that covers and protects tissues that line the stomach and small intestine. Often, the H. pylori bacterium causes no problems, but it can cause inflammation of the stomach's inner layer, producing an ulcer.
It's not clear how H. pylori infection spreads. It may be transmitted from person to person by close contact, such as kissing. People may also contract H. pylori through food and water.
Regular use of certain pain relievers. Taking aspirin, as well as certain over-the-counter and prescription pain medications called nonsteroidal anti-inflammatory drugs (NSAIDs) , can irritate or inflame the lining of your stomach and small intestine. These medications include ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve, Anaprox DS, others), ketoprofen and others. They do not include acetaminophen (Tylenol, others).
Other medications. Taking certain other medications along with NSAIDs, such as steroids, anticoagulants, low-dose aspirin, selective serotonin reuptake inhibitors (SSRIs), alendronate (Fosamax) and risedronate (Actonel), can greatly increase the chance of developing ulcers
STOMACH
Synonyms Of stomach
The stomach is also called the gaster or venter from which we have the adjective gastric applied to structures related to the organ.
Definition of 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 the oesophagus, and below to the duodenum. It acts as a reservoir of food and helps in digestion of carbohydrates, proteins and fats.
Location of stomach
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
DISSECTION OF STOMACH
Identify the stomach and trace it towards the abdominal part of oesophagus. Clean this part of oesophagus. Note various parts of stomach, e.g. cardiac end, fundus, body and pyloric parts. Trace the right and left gastric arteries along the lesser curvature and right and left gastroepiploic arteries along the greater curvature.
Tie two ligatures each at the lowest part of oesophagus and the pylorus. Remove the stomach by cutting between two upper ligatures through the oesophagus, left gastric artery, gastrophrenic ligament; and by cutting the pylorus between the lower two ligatures. Free the stomach from the adherent peritoneum if any and put it in a tray for further dissection.
Surface Marking Of stomach
(a) Cardiac orifice: It is marked by two short parallel lines 2 cm apart, directed downwards and to the left on the seventh costal cartilage, 2.5 cm to the left of the median plane
(b) Pyloric orifice: It is marked by two short parallel I lines 2 cm apart, directed upwards and to the right, on the transpyloric plane, 1.2 cm to the 1 right of the median plane.
(c) Lesser curvature: It is marked by joining the right margin of the cardiac orifice with the I uppermargin of the pyloric orifice by a J-shaped curved line. The lowest point of this I line reaches a little below the transpyloric I plane.
(d) Fundus: This is marked by a line convex upwards drawn from the left margin of the ] cardiac orifice to the highest point in the left fifth intercostal space just below the nipple.
(e) Greater curvature: This is marked by a curved j line convex to the left and downwards, drawn from the fundus to the lower margin of the pyloric orifice. It cuts the left costal margin between the tips of the ninth and tenth costal cartilages and extends down to the subcostal plane.
Shape and Position
The shape of the stomach depends upon the degree of I its distension and that of the surrounding viscera, I e.g. the colon. When empty, the stomach is somewhat I J-shaped (vertical); when partially distended, it becomes pyriform in shape. In obese persons, it is more horizontal. The shape of the stomach can be studied in the living by radiographic examination after giving a barium meal.
Size
The stomach is a very distensible organ. It is about 25cm. long, and the mean capacity is one ounce (30 ml) I at birth, one litre (1000 ml) at puberty, and \xh to 2 J litres or more in adults.
External Features
The stomach has two orifices or openings, two curvatures or borders, and two surfaces (Fig. 19.3).
Two Orifices
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 Tl 1. There is physiological evidence of sphincteric action at this site, but a sphincter cannot be demonstrated anatomically.The pyloric orifice opens into the duodenum. In an empty stomach and in the supine position, it lies 1.2 lei cm to the right of the median plane, at the level of the lower border of vertebra LI 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 (pyloros = gateguard) which feels like a large firm nodule; and
(b)by the prepyloric vein which lies in front of the constriction.
Two Curvatures
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.
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.
Two Surfaces
The anterior or anterosuperior surface faces forwards
and upwards.
The posterior or posteroinferior surface faces
backwards and downwards.
Two Parts Subdivided into Four
The stomach is divided into two parts. 1. Cardiac and 2.
pyloric by a line drawn downwards and to the left from
the incisura angularis. The larger, cardiac part is further
subdivided into the fundus and body, and the smaller,
pyloric part is subdivided into the pyloric antrum and the
pyloric canal (Fig. 19.3).
1 .a. 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.
l.b. 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 and (c) the parietal or
oxyntic cells which secrete HC1.
2.a. 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.b. The pyloric canal is about 2.5 cm long. It is
narrow and tubular. At its right end it terminates at the
pylorus.
Relations of Stomach
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
on to the diaphragm as the gastrophrenic ligament.
Cranial to this ligament a small part of the posterior
surface of the stomach is in direct contact with the
diaphragm (left crus). This is the bare area of the
stomach. 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 areas of the stomach related to these structures are
shown in Fig. 19.4. The diaphragm separates the
stomach from the left pleura, the pericardium, and the
sixth to ninth ribs. The costalB cartilages are separated
from the stomach by the transversus abdominis. Gastric
nerves and vessels 1 ramify deep to the peritoneum.
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 : (1) The diaphragm; (2) the
left kidney; (3) the left suprarenal gland; (4) the
pancreas; (5) the transverse mesocolon; (6) the splenic
flexure of the colon; and (7) the splenic artery (Fig.
19.5). 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.
DISSECTION
Open the stomach along the lesser curvature and
examine the mucous membrane with a hand lens.
Then strip the mucous membrane from one part and
expose the internal muscle coat. Dissect the muscle
coat, e.g. outer longitudinal, middle circular and
inner oblique muscle fibres. Feel thickened pyloric
sphincter. Incise the beginning of duodenum and
examine the duodenal and pyloric aspects of the
pyloric sphincter.
I Interior of Stomach
The stomach has to be opened to see its internal
structure.
1. The mucosa of an empty stomach is thrown into
folds termed gastric rugae. The rugae are longitudinal
along the lesser curvature and are 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,
be beware of your drinks.
2. Submucous coat is made of connective tissue,
arterioles and nerve plexus.
3. Muscle coat is arranged as under :
(i) Longitudinal fibres are most superficial, mainly
along the curvatures.
(ii) Inner circular fibres encircle the body and are
thickened at pylorus to form pyloric sphincter.
(iii) 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.
Blood Supply of stomach
B. Arterial Supply. The arterial supply of the stomach is from the following.
● Right and left gastric arteries which supply the lesser curvature (abdominal aorta → celiac trunk
→ common hepatic artery → right gastric artery; abdominal aorta → celiac trunk → left gastric
artery).
● Right and left gastroepiploic arteries which supply the greater curvature (abdominal aorta
→ celiac trunk → common hepatic artery → gastroduodenal artery → right gastroepiploic artery;
abdominal aorta → celiac trunk → splenic artery → left gastroepiploic artery).
● Short gastric arteries which supply the fundus (abdominal aorta → celiac trunk → splenic
artery → short gastric arteries).
C. Venous Drainage. The venous drainage of the stomach is to the following.
● Right and left gastric veins (right and left gastric veins → portal vein → hepatic sinusoids → central
veins → hepatic veins → inferior vena cava).
● Left gastroepiploic vein and short gastric veins (left gastroepiploic vein and short gastric veins →
splenic vein → portal vein → hepatic sinusoids→ central veins → hepatic veins → inferior vena cava).
● Right gastroepiploic vein (right gastroepiploic vein → superior mesenteric vein → portal vein →
hepatic sinusoids → central veins → hepatic veins → inferior vena cava).
The stomach is supplied by: (1) The left gastric artery, a
branch of the coeliac trunk; (2) the right gastric artery, a
branch of the common hepatic; (3) the right
gastroepiploic artery, a branch of the gastroduodenal; (4)
the left gastroepiploic artery, a branch of the splenic; and
(5) 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.
Lymphatic Drainage
The stomach can be divided into four lymphatic
territories as shown in Fig. 19.7. The drainage of these
areas is as follows:
Area a, or pancreaticosplenic area, drains into the
pancreaticosplenic nodes lying along the splenic artery,
i.e. on the back of the stomach. Lymph vessels from
these nodes travel along the splenic artery to reach the
coeliac nodes.
Area b drains into the left gastric nodes lying along
the artery of the same name. These nodes also drain the
abdominal part of the oesophagus. Lymph from these
nodes drains into the coeliac nodes.
Area c drains into the right gastroepiploic nodes that
lie along the artery of the same name. Lymph vessels
arising in these nodes drain into the subpyloric nodes
which lie in the angle between the first and second parts
of the duodenum. From here the lymph is drained further
into the hepatic nodes that lie along the hepatic artery;
and finally into the coeliac nodes.
Lymph from area d drains in different directions into
the pyloric, hepatic, and left gastric nodes, and passes
from all these nodes to the coeliac nodes.
Note that lymph from all areas of the stomach
ultimately reaches the coeliac nodes. From here it passes
through the intestinal lymph trunk to reach the cisterna
chyli.
Nerve Supply of stomach
Innervation. The innervation of the stomach is by the enteric nervous system which in the stom-
ach consists of the myenteric plexus of Auerbach only. The enteric nervous system is modulated by the
parasympathetic and sympathetic nervous systems.
1. Parasympathetic
● Preganglionic neuronal cell bodies are located in the dorsal nucleus of the vagus. Pregangli-
onic axons run in CN X and enter the anterior and posterior vagal trunks.
● Postganglionic neuronal cell bodies are located in the enteric nervous system, some of which
are the “traditional” postganglionic parasympathetic neurons that release ACh as a neurotrans-
mitter.
● The postganglionic axons terminate on mucosal glands and smooth muscle.
2. Sympathetic
● Preganglionic neuronal cell bodies are located in the intermediolateral cell column of the
spinal cord (T5 to T9). Preganglionic axons form the greater splanchnic nerve.
● Postganglionic neuronal cell bodies are located in the celiac ganglion.
● Postganglionic axons synapse in the complex circuitry of the enteric nervous system.
The stomach is supplied by sympathetic and
parasympathetic nerves. The sympathetic nerves are
derived from thoracic six to ten segments of the spinal
cord, via the greater splanchnic nerves, and the coeliac
and hepatic plexuses. They travel along the arteries
supplying the stomach. These nerves are (a) vasomotor,
(b) motor to the pyloric sphincter, but inhibitory to the
rest of the gastric musculature; and (c) and are the chief
pathway for pain sensations from the stomach.
The parasympathetic nerves are derived from the
vagi, through the oesophageal plexus and gastric nerves.
The anterior gastric nerve (made up of one or two trunks)
contains mainly the left vagal fibres, and the posterior
gastric nerve (again made up of one to two trunks)
contains mainly the right vagal fibres. The anterior
gastric nerve divides into : (a) A number of gastric
branches for the anterior surface of the fundus and body
of the stomach; and (b) two pyloric branches, one for the
pyloric antrum and another for the pylorus. The posterior
gastric nerve divides into:
(a) smaller, gastric branches for the posterior surface
of the fundus, the body and the pyloric antrum; and
(b) larger, coeliac branches for the coeliac plexus.
Parasympathetic nerves are motor and secretomotor
to the stomach. Their stimulation causes increased
motility of the stomach and secretion of gastric juice
rich in pepsin and HC1 (Fig. 19.8).
Functions of stomach
1. The stomach acts primarily as a reservoir of food.
2. By its peristaltic movements it softens and mixes
the food with the gastric juice.
3. The gastric glands produce the gastric juice
which contains enzymes that play an important role in
digestion of food.
4. The gastric glands also produce hydrochloric acid
which destroys many organisms present in food and
drink.
5. The lining cells of the stomach produce abundant
mucus which protects the gastric mucosa against the
corrosive action of hydrochloric acid.
6. Some substances like alcohol, water, salt and few
drugs are absorbed in the stomach.
7. Stomach produces the "mtrinsic/actor" of Castle
which helps in the absorption of vitamin B12.
_________ HISTOLOGY OF STOMACH_________
At the cardiac end of stomach the stratified epithelium
of oesophagus abruptly changes to simple columnar
epithelium of stomach.
Cardiac End
Mucous membrane: The epithelium is simple columnar
with small tubular glands. Lower half of the gland is
secretory and upper half is the conducting part.
Muscularis mucosae consists of smooth muscle fibres.
Submucosa: It consists of loose connective tissue
with Meissner's plexus.
Muscularis externa : It is made of outer longitudinal
and inner circular layer including the myenteric plexus
of nerves.
Serosa: It is lined by single layer of squamous
cells.
Fundus and Body of Stomach
Mucous membrane: It contains tall simple tubular gastric glands. Upper one-third is conducting, while lower two-thirds is secretory. The various cell types seen in the gland are chief or zymogenic, oxyntic or parietal and mucous neck cells. Muscularis mucosae and submucosa are same as of cardiac end.
Muscularis externa: It contains an additional innermost oblique coat of muscle fibres.
Serosa is same as of cardiac end.
Pyloric Part
Mucous membrane: There are pyloric glands which consist of basal one-third as mucus secretory component and upper two-thirds as conducting part. Muscularis mucosae is made of two layers of fibres.
Submucosa is same as in the cardiac end.
Muscularis externa comprises thick layer of circular fibres forming the pyloric sphincter. Serosa is same as of cardiac END.
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