Stomach
Pain
the stretching or spasmodic contraction of the smooth muscle
is The main reason for sensation of pain
in the stomach which is caused by its walls and is referred to the epigastrium.
It is believed that the paintransmitting fibers leave the stomach in company
with the sympathetic nerves. They pass through the celiac ganglia and reach the
spinal cord via the greater splanchnic nerves.
Gastric
Ulcer
pepsin is produced in
The mucous membrane of the body of the stomach and, to a lesser extent, that of
the fundus produce acid. The secretion of the antrum and pyloric canal is
mucous and weakly alkaline. The secretion of acid and pepsin is controlled by
two mechanisms: nervous and hormonal. The vagus nerves are responsible for the
nervous control, and the hormone gastrin, produced by the antral mucosa, is
responsible for the hormonal control. In the surgical treatment of chronic
gastric and duodenal ulcers, attempts are made to reduce the amount of acid
secretion by sectioning the vagus nerves (vagotomy) and by removing the
gastrin-bearing area of mucosa, the antrum (partial gastrectomy). Gastric
ulcers occur in the alkaline-producing mucosa of the stomach, usually on or
close to the lesser curvature. A chronic ulcer invades the muscular coats and,
in time, involves the peritoneum so that the stomach adheres to neighboring
structures. An ulcer situated on the posterior wall of the stomach may
perforate into the lesser sac or become adherent to the pancreas. Erosion of
the pancreas produces pain referred to the back. The splenic artery runs along
the upper border of the pancreas, and erosion of this artery may produce fatal
hemorrhage. 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.
Cancer
of the Stomach
Because the lymphatic vessels of the mucous membrane and submucosa
of the stomach are in continuity, it is possible for cancer cells to travel to
different parts of the stomach, some distance away from the primary site.
Cancer cells also often pass through or bypass the local lymph nodes and are
held up in the regional nodes. For these reasons, malignant disease of the
stomach is treated by total gastrectomy, which includes the removal of the lower
end of the esophagus and the first part of the duodenum; the spleen and the
gastrosplenic and splenicorenal ligaments and their associated lymph nodes; the
splenic vessels; the tail and body of the pancreas and their associated nodes;
the nodes along the lesser curvature of the stomach; and the nodes along the
greater curvature, along with the greater omentum. This radical operation is a
desperate attempt to remove the stomach en bloc and, with it, its lymphatic
field. The continuity of the gut is restored by anastomosing the esophagus with
the jejunum.
Gastroscopy
Gastroscopy is the viewing of the mucous membrane of the stomach
through an illuminated tube fitted with a lens system. The patient is
anesthetized, and the gastroscope is passed into the stomach, which is then
inflated with air. With a flexible fiberoptic instrument, direct visualization
of different parts of the gastric mucous membrane is possible. It is also
possible to perform a mucosal biopsy through a gastroscope
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